MEXICAN LONG-NOSED BAT

(Leptonycteris nivalis)

RECOVERY PLAN

September 1994
MEXICAN LONG-NOSED B~T

(Leptonycteris nivalis)

RECOVERY PLMI

Prepared by

Rodrigo A. Medellin, Ph.D.

Centro de Ecologia

UNAM, Ap. Postal 70—275

04510 Mexico, D. F.

Edited by

Carol J. Beardmore

U.S. Fish and Wildlife Service

611 E. 6th Street, Room 407

Austin, Texas 78701

for

Region 2

U.S. Fish and Wildlife Service

Albuquerque, New Mexico

Approved:

Date:
~LM~

Recovery plans delineate reasonable actions that are

believed to be required to recover and/or protect listed species.

Plans are published by the U. S. Fish and Wildlife Service,

sometimes prepared with the assistance of recovery teams,

contractors, State agencies, and others. Objectives will be

attained and any necessary funds made available subject to

budgetary and other constraints affecting the parties involved,

as well as the need to address other priorities.

Recovery plans do not necessarily represent the views nor

the official positions or approval of any individuals or agencies

involved in the plan formulation, other than the U. S. Fish and

Wildlife Service. They represent the official position of the

U.S. Fish and Wildlife Service ~jgy after they have been signed

by the Regional Director or Director as flppL2Y~4. Approved

recovery plans are subject to modification as dictated by new

findings, changes in species’ status, and the completion of

recovery tasks.

Estimates of cost and task duration as listed in Part III

have some uncertainty depending on the nature of the task.

Duration of some research tasks are unknown because they are

experimental in nature and it is difficult to predict the

interval required to complete the task or to attain required data

sets for statistical analysis. Costs of some tasks are uncertain

when they involve activities for which there exists no previous

cost experience and/or when they are dependent on earlier tasks.

LITERATURE CITKTIONS

Literature citations of this document should read as follovs:

U.S. Fish and Wildlife Service. 1994. Mexican Long-Nosed Bat

(Leptonycteris nivalis) Recovery Plan. U.S. Fish and

Wildlife Service, Albuquerque, New Mexico. 91 pp.
ACKNOWLEDGEMENTS

This work has benefited from interactions and suggestions

from H. Arita, G. Ceballos, and A. Shull. Agave censuses were

made thanks to the assistance of C. Equihua and A. Alonso—Mej Ia.

ii
EXECUTIVE SUMMARY

MEXICAN LONG-NOSED BAT RECOVERY PLAN

Current Species’ Status: This species is listed as endangered

and occurs in subtropical dry areas at medium and high elevations

in central and northern Mexico, the Big Bend area of Texas, and

Hidalgo County, New Mexico. Roost sites and foraging habitat are

crucial to this bat’s survival and have shown evidence of

disruption.

Habitat Requirements and Limiting Factors: Mexican long-nosed

bats need several roost sites distributed over the area of their

seasonal movements. They also need large areas with agaves and

other night-blooming plants for foraging. Major threats include

disturbance and destruction of roost sites, use of nectar sources

(agave plants) for production of alcoholic beverages, and

conversion of foraging habitat to agriculture.

Recovery objective: Downlisting from endangered to threatened.

Recovery Criteria: (1) at least six populations and supporting

habitat are protected and, (2) the six populations should be

maintained for 10 consecutive years and information indicates

that the populations and their supporting habitat will continue

to be maintained.

Major Actions Needed

:

(1) Develop effective roosting and foraging habitat protection.

(2) Implement increased public education.

(3) Conduct ecological studies applicable to recovery efforts

(i.e•, demography, feeding ecology, roost use).

(4) Monitor colonies/populations throughout range.

Total Estimated Costs of Recovery: (S 000’s)

Year Need 1 Need 2 Need 3 Need 4 Total

1995 100.0 110.0 62.0 9B.5 370.5

1996 157.5 91.0 333.0 77.5 659.0

1997 200.5 63.0 523.0 20.0 806.5

1998 79.5 12.0 107.0 20.0 218.5

1999 56.5 12.0 43.0 10.0 121.5

2000—2014 152.0 69.0 95.0 80.0 396.0

Total 746.0 357.0 1,163.0 306.0 2,572.0

Date of Recovery: If the plan is implemented as outlined, the

anticipated year that the downlisting criteria should be met is

2014.

iii
TABLE OF CONTENTS

Disclaimer and Literature Citation .. 1

Acknowledgements ii

Executive Si.1m~nary. . iii

Table of Contents......... . . iv

List of Tables and Figures v

I. Introduction and Background.. .... . . ... . . . . . .1

A. Legal Status andRecoveryPriority 2

B. Description.... . . . . . . . . . . . . . .3

D. Distribution...... . . . . . . . . . . . . 5

F. Life History/Ecology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Reproduction 10

Diet andFeedingBehavior...... 10

Population Size...... .14

Other Ecological Information ... .... 19

G. Reasons for Listing and Current Threats..........20

H. Conservation Measures .. 28

I. Recovery Strategy .. 29

II. Recovery . . . . . . . . . . . 33

A. Objective and Criteria. 33

B. Recovery Outline. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

C. Narrative Outline for Recovery Actions 39

D. Literature Cited........ ........... .. 53

III. Implementation Schedule . . . .60

IV. Appendices . . . . . . . .68

Appendix A: Preliminary list of food plants......68

Appendix B: Individuals and Agencies

Providing Comments on the Draft

Recovery Plan for the Mexican

Long—nosed Bat. . . . . . . . . . . . 69

Appendix C: Sunmary of Comments Received on

the Draft Mexican Long—nosed

Bat Recovery Plan and Service

Response 71

iv
LIST OF TABLES AND FIGURES

Tables

Table 1.

Table 2.

Population estimates of Leptonycteris nivalis

in Mt. Emory Cave, Big Bend National Park,

Texas . . . . . . . 16

Comparison of Leptonycteris nivalis roost

population estimates in Mexico 17

PaQe

Figure 1. Distribution of Leptonycteris nivalis Saussure... 6

Figure 2. Generalized physiographic areas of Mexico 24

Figure 3. Suggested locations of six populations of

Leptonycteris nivalis . ... ..... 30

V
I. INTRODUCTION AND BACKGROUND

The Mexican long-nosed bat (Leptonycteris nivaJlis) (also

known as greater long—nosed bat) inhabits northern and central

Mexico, the Big Bend area of Texas, and Hidalgo County, New

Mexico in the Upper Sonoran and Transition life zones (Brown

1982) that correspond to elevations ranging from 1,550 feet (500

m) to over 9,300 feet (3,000 in). Long-nosed bats feed on nectar

and pollen of agave and cacti flowers. The Mexican long—nosed

bat may be critically important as a pollinator for various

species of the plant genus Agave (Wilson 1985). Several caves in

central Mexico known to contain considerable numbers of bats in

the past now contain only small colonies or lack bats altogether

(Wilson 1985, Schinidly 1991). The reasons for the decline of

this species are not entirely clear, but are probably associated

with disruption and destruction of roosting sites and food

sources. Bat roost sites are increasingly subject to disturbance

by vandals and citizens attempting to control vampire bats.

Excessive harvest of agaves for the production of alcoholic

beverages may also be contributing to the decline of this

species.

1
A. LeQal Status and Recoverv Priority

The Mexican long—nosed bat was listed as endangered on

September 30, 1988 (USFWS 1988). This species was added to the

Texas Parks and Wildlife Department’s list of endangered species

on December 30, 1988 (Executive Order No. 88-002). The New

Mexico Department of Game and Fish listed this species as

endangered on November 30, 1990 (NMGF Reg. 682) (in ii~.). L.

nivalis was listed in the Mexican “Endangered Species Act” on May

17, 1991 (Diario Oficial 1991), as an endangered species.

The Mexican long—nosed bat has a recovery priority of 5.

According to the Service’s criteria, this indicates a species

with a high degree of threats and a low potential for recovery.

2
B. Description

The Mexican long-nosed bat is a medium-sized bat, 23⁄4-33⁄4

inches (70-90 mm) long and weighing 3~ — 1 ounce (18—30 g) (Wilson

1985). The third finger is more than 4 inches (105 mm) long

(Barbour and Davis 1969). The back is pale brown to gray. There

is no visible external tail; however, the tail actually consists

of three vertebrae (Wilson 1985). The interfemoral membrane

(uropatagium), a narrow strip of skin along the inside of each

leg, has long hairs extending beyond its edge (Schinidly 1991).

The snout is elongated and has a small, prominent, triangular

noseleaf on the tip. These bats have a long, protruding tongue

with inward-pointing, elongated papillae at its tip. Diagnostic

characters include the long snout and tongue, minute tail, and

hairs extending beyond the edge of the interfemoral membrane.

Species that might be confused with this bat are the lesser

long—nosed bat (L. curasoae yerbabuenae = L. sanborni) and the

long—tongued bat (Choeronycteris mexicana). The lesser long—

nosed bat, which is also listed as endangered, is slightly

smaller than the Mexican long—nosed bat, has shorter, stiffer

hair that is brown-tinged rather than gray, and the third finger

is shorter than the Mexican long-nosed bat’s (Schinidly 1991).

The lesser long—nosed bat’s range overlaps the western and

central portion of the Mexican long—nosed bat’s range. The long—

tongued bat can be distinguished by the wide uropatagiuin that

encases a visible tail and a muzzle that is longer and narrower

than the Mexican long-nosed bat (Schniidly 1991). The range of C.

rnexicana overlaps the Mexican long—nosed bat’s range completely

except the long-tongued bat is not found in west Texas (ArroyoCabrales et al. 1987).

3
C. Taxonomy

The Mexican long-nosed bat is a member of the family

Phyllostomidae (New World leaf—nosed bats) and is grouped in the

subfamily, Glossophaginae, with several other pollen—,

fruit-, and nectar-eating bats. The genus Leptonycteris is

characterized by two dental features, lack of the third molar and

presence of lower incisors (Walker 1975). Leptonycteris means

“slender bat” (leptos - slender, nycteris — bat), and the

specific name nivalis refers to the fact that the type specimen

was caught near snow line on the 17,816 feet (5,747 m)

extinguished volcano, Mt. Orizaba, in Veracruz, Mexico. The

original description by Saussure (1860), named these bats

Ischnoglossa nivalis. Many changes in nomenclature have

characterized these bats, and only recently the situation seems

to have been settled by Arita and Humphrey (1988, see their paper

for a review of classification and nomenclature). Arita and

Humphrey (1988) analyzed measurements from 1,951 long—nosed bat

specimens in the genus Leptonycteris and determined that L.

nivalis is a monotypic species. Some studies prior to 1988 may

have referred to L. nivalis, but because of Arita and Humphrey’s

determination those individuals were actually found to be L.

curasoae. Thus, literature prior to this time should be

carefully scrutinized before conclusions about L. nivalis are

made.

4
D. Distribution

Mexican long—nosed bats are known from medium— to high—

elevations, 1,550 to 9,300 feet (500 in to 3,000 in), in northern

and central Mexico, southwestern Texas, and southwestern New

Mexico (Figure 1) (Arita and Humphrey 1988, Hensley and Wilkins

1988). The Mexican states from which specimens have been

collected include Coahuila, Durango, Guerrero, Hidalgo, Jalisco,

Estado de Mexico, Michoacan, Morelos, Nayarit, Nuevo Leon,

Puebla, Queretaro, San Luis Potosi, Sinaloa, Tainaulipas,

Zacatecas, and the Distrito Federal (Arita and Humphrey 1988).

In Texas, the Mexican long—nosed bat is known from Big Bend

National Park (BBNP)(Borell and Bryant 1942, Easterla 1972) and

from the Chinati Mountains area (Mollhagen 1973).

Two specimens taken in Hidalgo County (in 1963 and 1967) in

southwestern New Mexico were recently determined to be L. nivalis

(Wilson 1985, Arita and Humphrey 1988). Their presence was

recently reconfirmed when they were netted over a tank in Hidalgo

County on August 26, 1992 (Hoyt ~ ~., in press). However, the

roost site has not been located and the status of the New Mexico

population has not been determined. The New Mexico locality is

over 400 miles (640 kin) disjunct from the Texas locality and over

437 miles (700 kin) from the northernmost record in central

Sinaloa.

Formerly, the Mexican long—nosed bat was thought to occupy a

much larger area, extending from southern Mexico to Guatemala,

but specimens collected from these areas have been assigned to L.

curasoae (Arita and Humphrey 1988).

The migratory path and nature of L. nivalis is not well

known. There are no references in the literature to roosts that

5
Figure 1. Distribution of LeptonycLeris ni vail, Sussure

6
are occupied year round nor whether seasonally occupied roosts

are occupied by the same colony when they return. A particular

colony may use one or more winter roosts, several migratory

roosts, and still other summer roosts. Food resource

availability probably drives this bat’s migratory “wanderings”.

Howell (jj3 litt.) speculated that Leptonycteris are more

accurately referred to as “nomadic”, taking advantage of peaking

food sources as they wander to traditional sites. L. nivalis’

sporadic use of Mt. Emory cave in Big Bend National Park may

reflect use in years when flower production is low in Mexico

(Easterla 1972). Conversely, bats may not move into BBNP if

flower production in northern Mexico is abundant.

7
E. Habitat

Mexican long-nosed bats mainly occupy mid- to highelevational [1,550—9,330 feet (500—3,000 meters)] desert scrub,

open conifer—oak woodlands, and pine forest habitats in the Upper

Sonoran and Transition Life Zones (Wilson 1985). They are one of

the most arid-adapted members of the Glossophaginae subfamily

(Koopinan 1981). Typical of the desertic part of the bat’s range

are species of columnar cacti, such as the card6n (Pachycereus

pringlei), and other plants such as creosotebush (Larrea

tridentata), elephant tree (Bursera sp.), and ocotillo

(Fouquieria splendens). In the mountainous part of the range,

vegetation is dominated by oaks (Quercus grisea, Q. emory, Q.

gravesei, and others), pines (Pinus cembroides), white cedar

(Cupressus sp.), juniper (Juniperus sp.), and other plants such

as tepoz~n (Buddleia sp.) and tejocote (Crataegus sp.).

Mesquites (Prosopis sp.), yucca (Yucca sp.), and agave plants

(Agave sp.) are shared by both major habitat types (Hensley and

Wilkins 1988, Rzedowski 1978).

Because of an apparent mutualistic relationship between

Mexican long—nosed bats and agaves, a decline in L. nivalis

populations might be reflected in the vegetation and

environmental conditions of the area. If this is the case, L.

nivalis could be considered a keystone species (Arita and Wilson

1987), which is a species that is considered critical to the

maintenance of habitat and species diversity of a community.

Easterla’s (1972) and Howell’s (1983) research at BBNP are

the only two known Mexican long-nosed bat foraging habitat

studies. Other study sites are either occupied by lesser long—

nosed bat or both Leptonycteris species where results might be

ambiguous. Easterla (1972) found Mexican long-nosed bats

(presumably foraging) in the following five ecological

associations, including some at lower elevations than previously

8
thought:

(1) arroyo-mesquite—acacia,

(2) lechuguilla-creosote bush-cactus,

(3) deciduous woodland,

(4) pinyon-juniper-oak woodland, and

(5) cypress-pine—oak.

The Mexican long—nosed bat is a colonial species that

usually roosts in caves, but can also be found in mines,

culverts, and hollow trees (Hensley and Wilkins 1988). Mt. Emory

cave in BBNP, the only roost site that has been described in

detail, is a shallow fault block cave with a small crumbling

entrance in which roosting occurs in an upper level on a high

ceiling (Wilson 1985). It is also described as having

considerably cooler air inside than outside during the summer and

a breeze blowing through at all times (Hensley and Wilkins 1988).

There are very few reports of Mexican long—nosed bats occupying

human-inhabited structures. Hall and Dalquest (1963) found a

group of about 200 bats in a hacienda in San Luis Potosi, and

Novick (1963) captured this species in two other haciendas in

Morelos and Veracruz. Generally, a lack of information

characterizes the state of knowledge about this species’ roosting

habitat.

9
F. Life Historv/Ecolocrv

Although L. nivalis has been known to science for over 130

years, no comprehensive ecological study has been conducted. This

is at least in part due to the fact that this species seems to be

scarce throughout its range (Barbour and Davis 1969; Easterla

1972). A major problem in comprehensively understanding the

bats’ situation is the virtual absence of almost any kind of

feeding, roosting, or reproductive ecology information. Many

reports in the literature are anecdotal and refer only to brief

encounters with these bats.

Reproduction - Reproductive information is limited to a few

records of lactating or pregnant females and speculation made on

the basis of observations of age structure, seasonal movements,

and sexual segregation (Alvarez 1963, Davis 1960, Easterla 1972

and 1973, Hall and Dalquest 1963, Wilson 1979 and 1985, Wilson et

al. 1985). Easterla (1973) took no pregnant bats and found no

direct evidence that parturition took place in Mt. Emory cave,

BBNP. He speculates that young are born elsewhere (probably

Mexico) before their arrival at Mt. Emory. He found lactating

females from June 18 to July 3, flying juveniles by the end of

June, and post-lactation females on July 15. Probably most

parturition occurs in May, although single late records of

possible late term females in July have been reported (Easterla

1972 and 1973). Wilson (1979 and 1985) has suggested that this

species might show the reproductive characteristic of two birth

peaks a year. The first and more noticeable peak occurs in the

spring, and the second may occur in September (Wilson 1979).

Diet and FeedinQ Behavior - Although most bats belonging to the

Phyllostomidae are confined to the American tropics,. L. nivalis

is one of three species that have evolved into nectarivorous

species adapted to desertic conditions in subtropical and

temperate regions. These bats eat nectar, and probably pollen

10
and some soft fruits; they may incidentally eat insects

associated with flowers or fruit. They become active late in the

night and leave their roosts in search of food plants, which are

mostly night-blooming plants that produce nectar at night, such

as agave plants (Davis 1960, Easterla 1972 and 1973, Gardner

1977, Hall and Dalquest 1963, Hensley and Wilkins 1988).

The following discussion of the genus Agave and its human

uses may be helpful to understanding the ecological relationship

between L. nivalis and Agave (Powell 1988).

“The large agaves are among the most spectacular desert

plants of the southwestern United States and Mexico. The

big long-lasting succulent leaves easily draw the attention

of those who appreciated plants, but the agaves perhaps are

best noted for the tall, attractive flowering stalks that

appear once in the life of each plant. The name century

plants, properly applied to any of the large agaves,

originated from the erroneous belief that each plant lives

for 100 years before it produces a flowering stalk during

the last year of its life. Actually the age of flowering is

variable, from eight to 20 (except reportedly 3-4 years in

Agave lechuguilla), after which a plant does produce one

rapidly growing flower stalk and dies, seemingly exhausting

all of its resources.

One of the most famous uses of agaves, especially in

Mexico, is the production of alcoholic beverages known as

pulque, mescal, and tequila. A sugary juice, which is the

source of pulque, is obtained from the starchy central stems

(crowns or heads) of certain large Mexican maguey agaves.

In order to obtain the juice for making pulgue, a deep hole

(juice basin) is made in the center of the crown of mature

plants by cutting out the terminal leaf bud, allowing the

green, yellowish, or whitish sap to exude into the cavity.

The juice is collected from the plants and transported to a

central locality where it is allowed to undergo

fermentation, a brewing process, yielding pulque. Pulque

has been described as the national drink of Mexico. Mescal

and tequila are distilled products of mash made from the

starchy crown. Tequila has become especially well—known for

its use in making “margaritas”, a favorite cocktail drink.

Agaves are cultivated extensively in Mexico and Central

America for the production of fibers known as sisal hemp and

heneguen. Indians of the southwestern United States also

used the native species for fibers, and as sources of food,

medicine, drink, and soap. The sweet food, mescal, was

11
prepared from the crowns of several of the larger agave

species, such as A. parryi, by removing the leaves and

baking the crowns or heads (“cabezas”) in pits lined with

hot stones. Heat converts the starches to sugars. The

Mescalero Apache derived their name from the extensive use

of mescal as food, but other Indians including the

Chiricahua Apache also ate mescal. Indians prepared a

highly intoxicating drink, also known as mescal, from

roasted crowns which were cut into pieces, pounded to a soft

pulp, and allowed to ferment.”

Agave flowers produce nectar only at night, mostly between

8:00 pm and 4:00 am (Howell 1979). Davis (1960) offered agave

panicles to L. nivalis, and had the following observations.

“It immediately began probing into the deep flowers with its

long snout. It lapped up nectar from some half—dozen

individual flowers before its hunger was appeased. The long

tongue was effective in reaching the bottoms of the deep

flowers.”

Howell (1983) described flock foraging behavior in L.

nivalis at BBNP. Flock foraging may benefit bats by increasing

foraging efficiency (e.g., discovering peak nectar production

periods), reducing predation risks, facilitating navigation, and

allowing penetration of new adaptive zones (i.e., by the

increased search and surveillance abilities provided by flock

foraging, they may enter areas not used previously) (Howell 1979,

Wilson 1979). An example of the latter might be when agaves are

introduced to an area (by man) or agave density increases, bats

may discover these areas more easily by flock foraging.

Howell (1979) analyzed the energetic relationships of the

closely—related lesser long-nosed bat. To have a balanced energy

budget, L. curasoae must consume at least 9.67 kilocalories

(kcal) each day. The study bats ingested about 4 grams (g) of

nectar in 20 minutes, which represented a net gain of 2.17 kcal.

By far the most energy-consuming activity was flight, which

included foraging. L. curasoae expended 63% of its daily energy

budget in only 13% of their daily activities (3 hours flying/24

12
hour period). Grooming, stretching, roosting, and interacting

with other bats also consumes energy. Between 20—minute foraging

bouts, L. curasoae flocks retire and cluster together on a tree

branch or other surface. This clustering behavior may save

energy spent in maintaining a high temperature. Even though L.

nivalis is slightly larger than L. curasoae, their energetics are

probably similar.

More recently, a series of studies by T.H. Fleming and his

students provided new information on L. curasoae. For example,

Sahley (1990) calculated that these bats would have to visit only

seven flowers of Pachycereus pringlei to replenish the estimated

3,244 joules (meter/kilogram/second unit of energy) expended in

flying the 15.5 miles (25 kin) that separate roosting and foraging

areas. Fleming ~ ~. (1990a) and Homer ~ ~J.,.(1990) found

that L. curasoae is highly predictable in its time of arrival to

and departure from feeding grounds (2200 and 0200 hours

respectively) and documented that some individuals visit the same

feeding areas for up to 2 weeks and could fly about 15.5 miles

(25 kin) nightly, spending at least 5 hours in flight each night.

Easterla (1972) noted that the century plants Agave scabra

(possibly misidentified = A. havardiana?, M. Fleming, NPS, pers.

comm.) and A. chisosensis (= A. glomeruliflora) were probably the

main foods of L. nivalis in the Chisos Mountains. However, he

found Mexican long—nosed bats at lower elevations where these two

plants do not occur. He suggested that the heretofore unknown

food source, A. lechuguilla, might be used at lower elevations.

Howell (1981) found lechuguilla pollen in the feces of Mexican

long-nosed bats in 1980, which was a drought year. In 1981 she

found no evidence of lechuguilla in the bats’ feces, leading her

to speculate that Mexican long—nosed bats may use alternate food

sources during environmental perturbations. However, A.

lechug’uilla’s flower structure and nectar production is not

consistent with chiropterophily (bat pollination). Thus, this

13
agave should not be considered a food source for Mexican long—

nosed bats (Howell 1981 and in litt.). A preliminary list of

plant species that may be used by these bats is presented in

Appendix A.

Evidence indicates an interdependence between some of the

food plants and bats. Bats obtain food from plants that need to

be pollinated. These plants depend at least in part on bats for

effective pollination (Howell 1979, Fleming ~ ~.J,.1990a and

1990b). While it is true that these bats depend on the plants

for food, the plants depend on bats only for cross pollination,

as the plants can reproduce vegetatively by sending shoots from

the bottom of the main stem. Tens of these small clones

frequently surround the parent plant, and if one dies there are

many remaining plants (G6mez-Pompa 1963, Howell 1979, Gentry

1982). Nevertheless, to guarantee an adequate amount of genetic

recombination and allow for natural selection to properly

operate, a species needs sexual reproduction, for which the bats

are apparently required (G6mez—Pompa 1963, Howell 1979).

PoDulation size — The Mexican long—nosed bat’s current population

size is difficult to estimate primarily because of uncertainty

concerning movements and the rarity of the species. Seasonal

movements are probably connected with climatic conditions that

stimulate flower blooming. These bats may also be somewhat

opportunistic in that they switch areas or remain in areas

depending on nectar availability. A group of bats may move to an

alternate roost making double counting a possibility, or,

conversely, if the second roost site is unknown, making it appear

as if the colony had disappeared.

The rarity of L. nivalis is indicated by Arita and

Humphrey’s (1988) examination of Leptonycteris specimens

deposited in collections in Mexico and the United States. They

found only 15% of the 1,951 specimens to be L. nivalis.

14
The most continuously monitored roost site is Mt. Emory cave

at BBNP, Texas (Table 1). Easterla (1972) calculated roosting

densities of 168 bats per square foot at Mt. Emory and estimated

population sizes from 1967 to 1971 for the colony (Table 1). In

1970, he found no bats in the cave, but in 1971 he estimated

8,025 bats were present. Later, Howell (1988) conducted a census

of this species in Mt. Emory cave also by counting the number of

bats per square foot and multiplying by the surface area covered

by the bats. Her estimates yielded a figure of about 4,942—5,990

bats in 1988. Howell’s density of bats per unit area is double

that of Easterla’s. The difference between Howell’s and

Easterla’s density figures is also an indication of the

difficulty in estimating population size.

During a survey for L. nivalis in central and northeastern

Mexico and adjacent United States, Wilson (1985) and Wilson ~

~j. (1985) found most colonies had decreased significantly or

disappeared (Table 2). The large groups of thousands of bats

reported in earlier accounts seem to have become rare or

disappeared altogether (Wilson ~, ~. 1985). However, some of

Wilson’s survey sites may have been located at water—holes, which

are not an important resource for a nectarivorous bat that has

kidneys to deal with a surplus of water in the nectar they

consume (D. Hafner, New Mexico Museum of Natural History, in

litt.).

15
Table 1. Population estimates of Leptonycteris nivalis in Mt.

Emory Cave, Big Bend National Park, Texas.*

YEAR NUMBERS SOURCE

1967 10,650 Easterla 1972, 1973

1968 5,000

1969 3,900

1970 0

1971 8,025

1983 1,000 ±200 Wilson 1985

1988 4,942 — 5,990 Howell 1988

1990 250 in late July M. Fleming (BBNP

pers. comm.):

Hollander—survey

1991 5,000 + M. Fleming (pers.

comm.): Neighborsurvey

1992 0 M. Fleming (pers.

comm.

1993 2,859 P. Homer, TX Parks

& Wildlife Dept.

(pers. comm.) & R.

Skiles, BBNP (pers.

comm.)

1994 present R. Skiles (pers.

comm.)

• Tfle metnocio±ogies&hdAatesof these estimates vary, result7ihg

in difficulty in making comparisons among years (see Cockrum and

Petryszn (1991) for discussion of Easterla’s estimates).

16
Table 2. Comparison of Leptonycteris nivalis roost population

estimates in Mexico *

SITE HISTORIC NUMBERS NUMBERS FROM

WILSON’S 1985

SURVEY

near Arteaga,

Nuevo Leon

24

(Baker 1956) 0

Cerro Potosi (3,505

m) near La Joha,

Nuevo Leon

10,000

Koestner (1941) 0

Cueva de los

Coyotes, Los

Amoles, Nuevo

Leon

no previous

estimate

25 - 50

Cueva del Diablo

Tepoztlan, Morelos

large #s in 1950

and 1960

(Wilson 1985)

30 — 50

Cueva de la Poza de

Moctezuma in

Oaxtepec, Morelos

no previous

estimate 2

Cueva del Cerro

Lago — near

Tequesquitengo,

Morelos

significant #s in

past (Wilson 1985)

large numbers —

unable to census

2 caves near Valle

de Bravo, Mexico

large colonies in

past (Wilson 1985)

10

17
SITE HISTORIC NUMBERS NUMBERS FROM

WILSON’S 1985

SURVEY

Near Los Ramones

(mine), Nuevo Leon

“ceiling covered w/

newborn young” in

1956

(Villa—R 1967)

1

near La Reforma,

San Luis Potosi

no previous

estimate 1

El Cedrito,

Coahuila

no previous

estimate 1

near Avandaro,

Mexico

no previous

estimate 5

near La Cienaga,

Nuevo Leon

no previous

estimate 10

near Aramberri,

Nuevo Leon

no previous

estimate

1

* The methodologies and dates of these estimates vary, resulting

in difficulty in making comparisons among years.

18
Other ecoloQical information — Mexican long—nosed bats are hosts

to a number of species of parasitic flies (families Streblidae

and Nycteribiidae), fleas (family Ischnopsyllidae), and mites

(families Spinturnicidae, Macronyssidae, and Argasidae). A

peculiar parasitic association has been noted by Phillips ~

(1969). Macronyssid mites infest the mouth tissue, particularly

the edges of gums and tissue surrounding molar roots. These

parasites damage the bone and leave characteristic perforations

that represent a useful taxonomic attribute (Phillips ~ kJ.

1969). All bats showing these perforations belong to L. nivalis,

although not all L. nivalis show the infestation; while none of

the L. curasoae examined exhibited the infestation (Phillips ~

al. 1969). Arita and Humphrey (1988) also found several L.

nivalis individuals without mite damage.

An additional confusing factor that reduces the information

on this species is that from 1940 through 1962, this species was

considered conspecific with the lesser long—nosed bat.

Undoubtedly, many of the occasional reports of L. nivajiis

actually belong to L. curasoae. This confusion was due to an

absence of valid and effective diagnostic characters to separate

the two species and the fact that, at least in some areas, the

two species coexist. Thus, at least part of the currently

available biological information on L. nivalis should be

attributed to L. curasoae, which leaves even less knowledge to

use in recovering the species.

19
G. Reasons for Listing and Current Threats

Mexican long-nosed bat populations appear to have

dramatically decreased during the last three decades. As judged

by the numbers of individuals in museum collections and by the

evidence in literature, L. niva.Lis was probably never a very

abundant species, although it was a fairly easy species to find

and collectors reported some roosts containing large numbers. In

the 1970s, scientific articles began showing that the species was

going through a serious decline (Howell and Roth 1981, Wilson

1985). Wilson (1985) (Table 2) found Mexican long-nosed bats

either completely absent or present in reduced numbers in known

roosts. The number of bats found represented only a fraction of

the populations reported in previous studies.

Causes of the decline have not been identified with complete

certainty, but they probably relate to human activities.

Modification or destruction of roost sites and foraging habitat

are probably the major threats (USFWS 1988). Other threats may

include pesticides, competition for roosts and nectar, natural

catastrophes, disease, and predation.

As with other colonial roosting bats, Mexican long—nosed

bats are probably limited by the number of sites that provide the

proper roosting environment especially for parturition (for other

species see Tuttle and Stevenson 1977 and Kunz 1982). The

availability of roost sites free from disturbance may be a

significant limiting factor for L. nivalis. While no known

Mexican long—nosed bats’ roosts have been rendered unusable, in

general roosting caves are becoming increasingly subject to human

destruction and disturbance (see Tuttle and Stevenson 1982 for a

list of articles). Vandalism and willful destruction of roosts

can affect both the bats that are present at the time of the

destruction and the physical conditions in the roost. A major

problem for bats all over Mexico (and other tropical Latin

20
American countries) is that frequently uninformed citizens

destroy all bats in a roost, believing them to be vampire bats.

An environmental education campaign is urgently needed in this

respect, particularly in the areas where the common vampire bat

(Desmodus rotundus) and Mexican long—nosed bat inhabit the same

roost.

L. nivalis is particularly sensitive to perturbation of the

roost; several authors have noted that Mexican long—nosed bats

are the first bats to take flight when humans intrude (Wilson

1985, Wilson et al. 1985). These bats are frequently found near

roost entrances, in the twilight region, and take to flight very

easily with the slightest noise or movement (Wilson ~ ~ 1985).

Generally, bat nursery colonies are sensitive and can be

destroyed with little effort (Gillette and Kimbrough 1976,

McCracken 1989).

Foraging habitat disruption and destruction has also been

identified as a threat to L. nival is. Foraging habitat can be

modified or destroyed by the harvesting of agave for inescal and

pulque, the expansion of agriculture, and other land uses. The

main threat to food plants is from “moonshining” not from

government regulated liquor industries (D. Howell and G. Nabhan,

pers. comm.). The large fields of planted agaves like those

around Jalisco probably supplanted few natural agaves prior to

the tequila industry. Public relations people from Jos6 Cuervo

tequila have investigated the advisability of letting a few rows

in each cultivated field go to flower to provide a food source

for bats (Howell, pers. comm.). Nabhan and Fleming (1993) have

estimated that bootleg inescal makers are eliminating between

500,000 and 1,200,000 wild paniculate agaves a year in Sonora

alone. Nabhan (pers. comm.) indicated that in no place were

agaves completely wiped out but that the agaves left to bloom in

the Sonora study area are often widely dispersed or in

inaccessible areas which make harvesting unproductive. Although

21
it is not known how far L. nivalis will fly to forage or how

clumped the resource must be to be energetically productive, at

some point widely spaced flowering stalks and distance to clumps

become inefficient and affects reproduction and survival. Nabhan

and Fleming (1993) suggest that the “tequila connection” is not

as important as was once thought. “There are few places in

Sonora or elsewhere in Mexico where wild Aaave harvesting has

eliminated a significant percentage of nectar—producing genets...

because indigenous harvesters know how to disrupt apical

dominance.., to encourage vegetative offshooting... before

removing the ‘mother plant’ for mescal production.” However, by

removing the flowering stalk “head” thus encouraging vegetative

offshooting, they delay flowering (until the vegetatively

produced plants mature) and eliminate the possibility of the

flowering stalk becoming available to the bats that year. The

impact of alcoholic beverage production on Mexican long—nosed bat

foraging and survival is far from clear.

Although traveling through Mexico one can see large

quantities of potential food plants for this species (i.e.

agaves), these are, in fact, rarely left to flower and thus be of

use to the bats. Agave head sugar content is highest precisely

when the plant is about to send up the flowering stalk, and thus,

the plants are harvested before the panicle flowers. An informal

census (Medellin, pers. obs.) of conspicuous agave inflorescences

was carried out along a 120-mile (200-kin) section of highway

(within the original range of the species), from Puebla to

Orizaba. This area is flat, about 4,650—5,270 feet (1,500—1,700

meters) above sea level, and has been disturbed primarily for

agriculture for several decades. Adjacent land plots are

frequently separated by lines of agaves and/or the exotic piru

(“brazilian pepper”, Schinus molle). The agaves are used mostly

for local, domestic, low-scale production of pulque. All highly

visible, live, yellow flower—bearing agave inflorescences were

counted in a 930 feet (300 in-wide) transect (465 feet (150 in) on

22
each side of the road) during the peak of flowering in the area.

Even though, due to lack of mechanization and irregularity of

exploitation, agaves are allowed to produce inflorescences in

this area, a density of only 5.82 inflorescences per square mile

(2.21 inflorescences per square kin) in May 1990 and 6.15

inflorescences per square mile (2.34 inflorescences per square

kin) in June 1990 was counted. This represents a low density,

although knowledge of the foraging needs of these bats prevents

further comment on minimum required food plant densities. It is

interesting to note that while censusing the flowering agaves,

none were found in the stretch of road going from Mexico City to

Puebla, which contained significant L. nivalis populations in the

past.

Because of the apparent mutualistic relationship between

Mexican long-nosed bats and agaves discussed earlier, a decline

in L. nivalis populations could possibly mean an accompanying

change in agave reproduction and distribution. Wild agave stock

would be important as the source of new genetic material for an

industry that exploits vegetatively cultivated lineages (Arita

and Wilson 1987).

Large areas of both Sierra Madre Oriental and Occidental,

and the Mexican Plateau (Figure 2) have been transformed to

agriculture or to other land uses that destroy or modify the

original habitat. This bats’ habitat may have been converted to

crops or rangeland species in certain areas. Habitat

transformation in an area is often entire and no significant

amount of original vegetation is left in the area.

23
Figure 2. Generalized physiographic areas of Mexico.

Pacific slope and plain

E Gulf slope and plain

~ Sierra Madre Oriental and Occidental

E Mexican Plateau

24
The use of pesticides may also negatively affect L. nival is.

Because long—nosed bats are nectarivorous, they are probably not

as susceptible to pesticide effects as insectivorous bats.

However, pesticides may be applied in a way that covers

everything that is exposed, and thus, might fall on the bat’s

food plants. When bats feed on the nectar, soft fruits, or

incidentally on insects, pesticides might be consumed by the

bats. Reidinger (1976) found lesser long-nosed bats in Arizona

and Sonora, Mexico contained the least amount of organochlorine

residues of all bats sampled. Reidinger (1976) did not speculate

on the possible effects of the pesticide level he did find in

Leptonycteris.

Mexican long—nosed bat populations may be affected by some

natural limiting factors such as increased competition for

roosts and nectar, and predation that are exacerbated by human—

caused activities. Even though competition and predation are

integral parts of the biology of any species, both may have

increased due to human activities and might have a compounded

detrimental effect on an already low Mexican long—nosed bat

population. Interspecific competition may occur between L.

nivalis and L. curasoae and Choeronycterls xaexicana.

Nevertheless, all three species seem to be of concern at the

moment, with L. curasoae also listed as endangered and C.

mexicana listed as a candidate species.

Competition for roost space may also occur with other bat

species, particularly where caves are not abundant and cattle

ranching and livestock production have artificially increased

vampire bat populations by providing easy and abundant prey.

Vampire bats commonly occupy the highest, darkest, warmest places

in caves (Medellin, pers. obs.; Turner 1975). On several

occasions, vampire bats have been found to replace non—vampire

species (Medellin, pers. obs.). Turner (1975) also noted a

similar trend; when the number of vampire bats increased, the

25
number of non—vampire bats in the roost decreased or remained

constant, but rarely increased.

In addition, some avian nectar “robbers” may negatively

affect nectar availability for L. nivalis. Several birds (among

them Diglossa spp., honeycreepers or flower—piercers) obtain

nectar by perforating the base of closed nectar—laden flowers

during the day, thus removing the resource with no advantage to

the plant and decreasing nectar availability for bats (Arizmendi

and Dirzo 1992).

Although there are no documented cases of predation of L.

nivalis, they probably experience predation from owls, hawks,

snakes, and mammals (including raccoons, cats, and ringtails)

similar to other bat species (Tuttle and Stevenson 1982). In the

case of L. nivalis, predation does not seem to be a particularly

important limiting factor. However, the impact of predation is

likely much greater than generally realized and low reproductive

rates of most bats greatly increase the importance of even low

predation rates (Tuttle and Stevenson 1982). Anthropogenicallycaused increased populations of domestic or feral cats and other

predators may affect survival of bat colonies, particularly

maternity colonies near human habitations.

Other natural events that may impact Mexican long—nosed bats

are climate and natural catastrophes. Some particularly severe

winters may have an effect on the amount of food availability.

For example, in mid—elevation areas a late— or early—season

freeze may dramatically reduce the number of live flowers,

particularly since these flowers are open at night when the

coldest temperatures occur. Such conditions could cause

starvation or migration of bat colonies. Additionally, roost

destruction due to earthquakes, floods, or other natural causes

may destroy entire bat colonies. These factors would not pose a

serious threat to the species if populations were at their

26
original numbers. However, if the species is receiving

additional pressure from human activities, natural disasters may

play a critical role in the species’ survival.

One study has suggested that rabies may be present in

Mexican long-nosed bats (Villa-R and Jim6nez 1962). However,

there is some doubt regarding the specific identification of the

bats in that report. Additionally, the incidence of rabies is

very low in non-sanguivorous (non-blood eating) bats, less than

half of 1 percent (no higher than that seen in many other

animals) (Tuttle 1988). No real threat is apparently posed by

other diseases for this species, although this factor can not be

completely discounted.

27
H. Conservation Measures

Most research on long—nosed bats has been done on the lesser

long—nosed bat, with some projects in northern Mexico and Arizona

ongoing. Very few studies have examined L. nival is, and even

fewer have been published. The surveys examining the majority of

the species’ range were done in 1983 and 1984 (Wilson 1985). No

known complete surveying or monitoring of these or other sites

has since been conducted.

Big Bend National Park’s Mt. Emory cave is the only known

protected Mexican long—nosed bat roost on public land in the U.S.

and is the only roost that has had a multi-year monitoring

effort. The National Park Service plans to continue this

monitoring effort (M. Fleming, BBNP, pers. comm.).

An on-going project conducted by Dr. Alfonso Valiente, of

the Centro de Ecologia, Universidad Nacional Autonoina de Mexico,

indirectly involves L. nivalis. He is monitoring nectar and

pollen production, determining pollinating agents, and studying

the reproductive biology of the cactaceae in the xeric Valle de

Tehuachn, State of Puebla, which is within an area of known L.

nivalis occupancy (Medellin, pers. obs.).

A vampire bat control/education project is intermittently

ongoing in different areas of Mexico and is planned to coalesce

into a national program. Also, an initiative is planned to

approach tequila producers in the highlands of Jalisco with

information about protecting bats. This project is planned to

begin operation in mid-1994.

28
I. Recovery Stratecrv

This recovery plan outlines the steps needed to downlist the

Mexican long-nosed bat from endangered to threatened. Two steps

should be taken immediately to prevent further population

declines and possible extinction. The most crucial of these two

steps is the protection of known occupied and unoccupied roost

sites, which will provide needed shelters along the bat’s

migratory path and maternity roosts. These actions should be

accomplished quickly. Roosting habitat is probably the most

critical limiting factor for the Mexican long—nosed bat. A

“grassroots” education program targeted at communities near key

roosts may be effective in changing misperceptions about bats.

Protecting suspected foraging habitat follows protecting

roosting habitat in importance. Because locations and densities

of food resources are not well known, this step will be more

difficult to accomplish. Several recovery tasks address the

collection of data on the foraging requirements of these bats and

will assist in determining foraging habitat needs. Until this

work is done, agaves and other night—blooming plants that are

possible food sources for L. nivalis should be protected at least

within 24 miles (40 kin) of known roosts. This distance is based

on movements documented by Sahley (1990) and Homer ~ ~j,. (1990)

and the distances bats travel in BBNP from Mt. Emory cave to

suspected foraging areas (Easterla 1972).

At least six populations of L. nivalis should be protected

before downlisting is considered. The six suggested populations

are based on Arita and Humphrey’s (1988) grouping of L. nivalis

specimens (Figure 3). To meet this criterion, considerable work

will need to be done on defining Mexican long-nosed bat

populations, and determining their seasonal movements so that

roosting and foraging habitats can then be protected.

Information gathered from recovery tasks may refine the numerical

29
Figure 3. Suggested location of six populations of Leptonycteris nivalis (based

on Arita & Humphrey 1988).

30
target (six) of populations needed, especially if the bats’

movements cloud the distinction of populations. In the same

regard, the BBNP and New Mexico colonies are considered as parts

of separate populations for this criterion. This also may be

revised, if it is discovered they are part of the same

population. The locations of the six populations were made

relatively large to allow for movement if natural fluctuations in

nectar production and other natural events cause the bats to

move. The six areas were also designed to be distributed

throughout the range of the species. Whether the clusters of the

locations represent six distinct populations or 1 — 6 populations

that move between these areas, the thought is that by protecting

these areas the species will be provided for over a significant

portion of its range (about 80%).

Landowners and communities in areas where existing

populations occur should be informed of the presence and

importance of the species, as well as the requirements of United

States and Mexican laws. Additionally, they should be supplied

with information about the biology of L. nivalis (including its

vulnerability) and steps recommended for protection. Landowners

should be kept continuously informed of any new information

obtained on the species and conservation opportunities,

particularly about monitoring programs, vampire bat education

programs, leaving certain percentages of blooming agaves,

possible cave gating, locating funding sources for protection

efforts, and debt—for—nature swaps.

Additionally, new roost sites may be discovered fortuitously

or may be unknowingly destroyed through other actions. Thus, any

mines (or other possible roost sites) that are proposed to be

closed or gated within the possible range of this species in the

United States should have surveys conducted at the appropriate

season to determine if they are used by Mexican long—nosed bats.

31
Population biology data needed to analyze the viability and

structure of L. nivalis populations needed for recovery can be

collected at the same time protection efforts are underway. This

research does not have as high a priority as the immediate roost

and foraging habitat protection and education needs. These data

may be used to refine or revise the reclassification criteria

contained in this plan and to determine whether delisting is

possible.

Other actions needed to affect L. nivalis recovery are less

well defined because of the lack of basic biological information

on this species. Therefore, many of the recovery tasks outlined

discuss research that is needed to determine further recovery

needs. Factors such as disease, predation, parasites, pollution,

interspecific competition, and catastrophes should be studied and

evaluated to determine their impacts on limiting the recovery of

the Mexican long—nosed bat.

32
II. RECOVERY

A. Objective and Criteria

Objective: The objective of this recovery plan is to outline

steps necessary to recover the Mexican long—nosed bat to a point

where it can be reclassified from endangered to threatened. The

prospects for complete recovery and delisting of this species are

uncertain primarily because of the lack of knowledge about what

constitutes a viable population for this species. Therefore, an

interim recovery objective of reclassification is identified.

Criteria: The Mexican long—nosed bat will be considered for

reclassification from endangered to threatened when:

(1) at least six populations and supporting habitat are

protected. These populations should be distributed

throughout the range of the Mexican long—nosed bat

similar to those indicated in Figure 3. Habitat to

support the summer, migratory, and winter roosts and

foraging of the populations should be protected within

each area. The BBNP, Texas, and Hidalgo County, New

Mexico, sites in the U.S. should be part of two of the

populations and the remaining four should be entirely

in Mexico, and

(2) the six populations should be maintained for at least

10 consecutive years and information should indicate

that roost sites, foraging habitat, and populations are

well established and will continue to be maintained.

All known roost sites (whether occupied or not) and

associated habitat (especially foraging habitat) should be

protected and maintained at least until the recovery criteria are

established. Because so little is known about what constitutes a

33
population and which roost sites are essential, the loss of one

crucial roost site might preclude one of the six populations from

being established. The recovery strategy for this species

intends to protect and enhance (where appropriate) existing

Mexican long—nosed bat roosting sites and associated foraging

habitat.

Reclassification to threatened cannot occur until what

constitutes a population and how a population migrates and uses

habitat is understood. Criterion 1 will entail considerable work

to determine what constitutes a Mexican long—nosed bat

population. Currently (1994), there are no data that describe a

population of Mexican long—nosed bats. This information will be

collected as the result of research described in the recovery

tasks and should include searches for other roost sites as well.

Then, protection for at least six populations should be

established. The six populations is a tentative number based on

Arita and Humphrey’s (1988) grouping of specimens. Information

gathered from recovery task implementation can be used to refine

the number of populations required for downlisting.

Data should also be collected to determine what a viable

Mexican long—nosed bat population is, how many populations are

needed, and whether full recovery is possible and, if so, what

will be necessary to fully recover the species. The feasibility

of total recovery and delisting will be examined as part of this

plan. If found to be feasible, criteria for determining when

delisting could occur, will be developed as part of this plan,

and the plan will be revised to incorporate these new objectives

and criteria.

These reclassification criteria are preliminary and may be

revised as new information becomes available (including research

specified as recovery tasks in this plan). The estimated date

for attaining the objective of this plan (downlisting to

34
threatened) is the year 2014. This estimated date is based on

about 10 years to complete the research necessary to determine

the 6 populations and 10 years after that to ensure the protected

populations are maintained.

35
B. Recovery Outline

This section outlines recovery tasks needed to attain the

objective of this plan: reclassification of the Mexican longnosed bat to threatened. Section II. C of this plan includes

more detailed information on the tasks outlined here.

1. Protect, monitor, and locate roosting sites

1.1 Protect Mexican long—nosed bat roosts

1.11 Contact private and public landowners/managers

1.111 Identify landowners/managers of roost sites

and offer information on Mexican long—nosed

bats

1.112 Work cooperatively with landowners/managers

to establish protected roost sites

1.12 Develop and implement informational/educational

programs about bats for the general public

1.121 Develop public support through a bat

education program

1.122 Develop and implement a program that

addresses vampire bat issues

1.13 Determine if cave gating is appropriate for this

species and install cave gates if appropriate

1.14 Ensure compliance with Federal and State laws and

regulations

1.141 Ensure compliance with Federal and State

laws in the United States

1.142 Ensure compliance with environmental laws in

Mexico

1.15 Investigate other protective actions

1.151 Investigate debt-for-nature swaps

1.152 Investigate enacting new environmental laws

(both Federal and State) in Mexico

1.153 Develop Spanish translation of this

Recovery Plan

36
1.2 Monitor known occupied and unoccupied roost sites

1.21 Develop a standard method for monitoring roosts

1.22 Monitor known occupied and unoccupied roost sites

1.3 Survey for new roosts

1.31 Characterize existing roosts

1.32 Predict where roosts might occur

1.33 Locate possible roost sites

2. Determine foraging needs and protect foraging habitat

2.1 Determine foraging habitat needs during all parts of the

bat’s life cycle

2.11 Determine feeding behavior

2.111 Inventory food plants used by the bats

2.112 Determine amount of nightly food intake

per bat and per colony

2.113 Determine nightly flight distances traveled

to obtain food

2.12 Identify and study foraging habitat

2.2 Protect foraging habitat

2.21 Determine impact of agave harvest on Mexican

long—nosed bat survival and recovery

2.22 Work with liquor industry and local producers to

protect foraging habitat

2.23 Work with agricultural users to protect foraging

habitat

2.24 Ensure compliance with laws and regulations

that protect foraging habitat where needed and

appropriate

2.25 Protect foraging habitat through other methods

including education

3. Determine and control other threats and limiting factors

3.1 Identify other threats and limiting factors

3.2 Eliminate or reduce limiting factors/threats

37
4. Model population viability

4.1 Obtain demographic data

4.2 Determine and monitor migration times, routes, and

habitats

4.3 Determine levels of genetic variability within and among

populations in different geographic areas

4.4 Perform a population viability analysis

4.5 Determine size, location, and configuration of habitat

needed to support viable populations

38
C. Narrative Outline for Recovery Actions*

1. Protect. monitor. and locate roost sites. The availability

of roosting habitat and its freedom from disturbance may be

the most crucial limiting factor for these bats. Known

occupied and unoccupied roost sites should be protected

through a number of methods. These sites should be monitored

to detect population trends. Also, searches for other roost

sites should be conducted, and any that are found should be

protected and monitored.

1.1 Protect known Mexican long—nosed bat roosts. Protection

of occupied and unoccupied roost sites should be

accomplished through contacts with landowners/managers

and enforcement of laws and regulations. In addition,

bat education programs targeted at the general public

near important roost sites and other creative protection

methods should be employed.

1.11 Contact ~~rivate and Dublic landowners/managers

.

Information and assistance should be offered to

private and public landowners/managers (and ejido

people in Mexico) of known occupied and unoccupied

roost sites to encourage bat protection efforts.

1.111 Identify landowners/inana~ers of roost sites

and offer information on Mexican lona—nosed

bats. Provide information on the biology,

economic value, and ecological importance

of Mexican long—nosed bats and the

fragility of roost sites.

* Tasks will be developed and conducted in the language

appropriate to the situation, Spanish and/or English.

39
1.112 Work cooperatively with landowners/inanaQers

to establish protected roost sites. Advise

landowners of the significance of their

property to the survival of this species,

what they can voluntarily do to protect

roost sites, and of activities known to be

detrimental to the bats. Develop roost

site management plans if appropriate. A

land ownership pattern prevalent in Mexico

is the ejido system. People live on

government—owned land and come to treat it

as if it were their own. In some areas,

ejido people may be a key factor in

implementing local roost protection

programs and later may become bat educators

themselves. Maintaining contact with the

landowners/managers over the years is

necessary to assure support. Funding

assistance may be sought for specific

management projects.

1.12 Develop and implement informational/educational

proarains about bats for the aeneral public. Human

disturbance of roosts is believed to be one of the

major reasons for the decline of the Mexican long—

nosed bat. Many times the reasons for disturbing

bat roosts is born out of long—held misconceptions

and misinformation about bats in general.

“Grassroots” education programs in communities

near key roosts are often the most effective.

1.121 Develop public su~~ort through a bat

education program. The fate of endangered

bats depends in large part upon public

support and cooperation. The pursuit of

40
public support must be carefully planned to

encourage concern for the survival of the

species and its habitat without increasing

disturbance to roosts by curious

individuals. An education program should

address basic bat biology, myths and facts,

and benefits bats provide. Good education

materials should be provided. If informed

of the benefits bats provide, local people

may serve as educators to inform others of

the need to maintain healthy bat

populations.

1.122 Develoo and implement a program that

addresses vampire bat issues. In many

instances, local citizens kill all bats in

a colony because they believe every bat is

a “vampire bat”. Frequently, the result is

that all bats except vampire bats are

killed. This program should include

information on how to identify vampire bats

and, if they are a problem, appropriate

management techniques that can be used to

keep vampire bats from feeding on

livestock.

1.13 Determine if cave patina is appropriate for this

species and install cave aates if appropriate. If

cave gating would prevent disturbance and have no

adverse effects on bats, then this option should

be studied and its effectiveness and

appropriateness assessed. If found to be

appropriate, installing cave gates should be

pursued with the landowner/managers on a case—by—

case basis.

41
1.14 Ensure compliance with Federal and State laws and

recrulations. The protection provisions of the

Endangered Species Act (Act) should be enforced in

the United States. Mexico can apply the

protective measures of applicable laws in Mexico.

1.141 Ensure compliance with Federal and State

laws in the United States. Roosts and

habitat should be protected through

regulatory measures provided by the Act.

Section 9 of the Act specifically prohibits

take of an endangered species without the

appropriate permit. Section 7 of the Act

requires that Federal agencies consult with

the Service on any action they authorize,

fund, or carry out that may affect listed

endangered or threatened species. Several

other Federal, State, and local regulations

(such as the Lacey Act, state endangered

species regulations) also contain

protective provisions for endangered

species and should be enforced.

1.142 Ensure compliance with environmental laws

in Mexico. Bat colonies and habitat should

be protected through Mexican laws and

regulations. Cave vandalism and vampire

bat “control” is of particular concern.

The Mexican Ministry of Ecology (Secretarla

de Desarrollo Social) has suggested

employing grassroots resources to fulfill

the task of protection.

1.15 Investicrate other protective actions

.

Wherever appropriate, alternative protective

42
actions should be sought to supplement those

discussed above. A combination of creative and

cooperative actions will be needed to recover the

Mexican long—nosed bat.

1.151 Investicrate debt—for—nature swans. Examine

the feasibility of debt-for-nature/

conservation swaps and prepare and submit

proposals for them if appropriate. These

proposals could include land acquisition,

environmental education, or enforcement

efforts. Swaps may be used to fund

operations and management. Mexico has

begun to be involved in such actions; the

first was signed in March 1991 to protect

the region known as Selva Lacandona in the

south. The involvement of Mexican nongovernmental organizations (currently

undergoing a significant expansion and

growth process) and international

conservation agencies is often essential to

the success of these projects.

1.152 Investicrate enactina new environmental laws

(both Federal and State) in Mexico. Other

legal options should be investigated to

protect the Mexican long-nosed bat. At

present, there is a new environmental law

being prepared for submission to the

Senate. The Federal government and many

states in Mexico are at present undertaking

ecological tasks as their responsibility.

New environmental laws may include (but are

not confined to) Federal and State

endangered species laws, protection decrees

43
(such as presidential decrees), and the

recent entrance of Mexico to the Convention

on International Trade in Endangered

Species (CITES).

1.153 Develop Spanish translation of this

recovery plan. To facilitate use in

Mexico, a Spanish translation of this

recovery plan should be developed.

1.2 Monitor known occupied and unoccupied roost sites. Data

are needed to help determine Mexican long—nosed bat

population estimates, to detect declines and the response

of populations to recovery efforts.

1.21 Develop a standard method for monitorina roosts

.

The monitoring effort could be conducted at

various levels from a very minimal effort such as

presence/absence to a more comprehensive level

such as complete roost censuses. However, a

minimum level of monitoring effort should be

standardized over the bat’s entire range. More

comprehensive monitoring can be done at selected

sites. One possible census method is the use of a

photographic assessment of the bat—covered

ceiling, showing scale to properly estimate the

number of bats. Monitoring maternity roosts may

be an efficient way of monitoring population

trends because it is believed that females are

faithful to maternity roosts while young are

nonvolant and they do not fly with young (Peggy

Homer, pers. comm.) Exodus counts may be

unreliable because Mexican long—nosed bats swirl

and go in and out of the entrance. Consideration

should also be given to seasonality, cave

44
temperature, time of day, and frequency of

monitoring. Presence may be indicated by locating

the “gold—colored” (pollen—colored) fecal material

outside of the roost. This technique may prevent

or minimize disturbance of roost inhabitants.

Precautions needed to avoid disturbing the bats

(such as moving slowly and with extreme caution,

covering headlainps with a deep red filter, and

avoiding any loud noises) should also be included

in the standardized method. Additional details on

precautions can be obtained in Thomas and LaVal

(1988) and Protection of Bat Roost Guidelines

subcommittee (1992).

1.22 Monitor known occupied and unoccupied roost sites

.

Monitoring should serve two purposes: (1) to

determine if recovery efforts are effective, and

(2) to document colony size fluctuations. Because

of this species’ migratory nature, monitoring a

particular roost may not produce an accurate

population estimate. A particular colony may use

one or more winter roosts, several migratory

roasts, and still other summer roosts. A mark—

recapture project may be needed to provide

information on short—term movements among roosts

and indicate how often “double counting” occurs.

Significant fluctuations or declines over a period

of years may forewarn of possible local

extirpation or even extinction.

1.3 Survey for new roosts. Identification and protection of

additional roasts is needed to recover the Mexican longnosed bat. To do this, existing roasts (summer, winter

and migratory) should be characterized, and searches for

others with similar characteristics should be conducted.

45
Roosts may also be located by other methods including

radio-tracking captured individuals.

1.31 Characterize existing roosts. Study existing

roosts that are used during all parts of the bat’s

life cycle and during all seasons. Studies should

include microclimate, soils, geology, geography,

altitude, and surrounding habitat.

1.32 Predict where roosts miaht occur. Based on the

information found in Task 1.31, location of roosts

should be predicted using geology, remote sensing,

and other information and equipment available.

1.33 Locate possible roost sites. Survey for possible

roost sites using the predictions from Task 1.32,

prioritized by public lands and interested

landowners. Once roosts are located, they should

be protected and monitored (Tasks 1.1 and 1.2).

Roost sites may also be located by radio—tracking

captured individuals (S. Altenbach, University of

New Mexico, j~.n 1i~.)

2. Determine foracrmna needs and protect foraging habitat

.

Many aspects of the Mexican long—nosed bat’s foraging

habitat, such as the distance they will travel from the roost

site to obtain food, seasonality of plant species used, and

the density of flowering stalks needed are unknown.

Protection of foraging habitat should focus on working with

large and small scale liquor producers and people converting

undisturbed land to agricultural use.

2.1 Determine foracrmna habitat needs during all tarts of the

bat’s life cycle. Foraging habitat requirements will

46
determine how and where protection efforts should be

focused.

2.11 Determine feeding behavior. Studies of feeding

behavior should include variation in foraging by

sex, age, time of year, and locale; plant species

used; and flight distances traveled to secure food.

Protection of a variety of foraging habitat types

may be needed, depending on these variables.

2.111 Inventory food plants used by the bats. An

inventory of plants used by the bats as food

is needed to further protection efforts.

Plants other than agaves may be important

food sources at certain times of the year,

locations, etc. Additionally,

investigations should determine if food

resources used vary by sex and age of the

bat, time of year, and locality,

particularly if one plant species is crucial

to the bat at a particular point in the

bat’s life cycle.

2.112 Determine amount of nicrhtlv food intake oer

bat and ~er colony. This information will

assist in assessing the plant population

size, plant density, and size and

configuration of the area required to be

protected to sustain specific colonies.

2.113 Determine nightly fliaht distances traveled

to obtain food. The distances bats fly to

foraging habitat is needed to help design

foraging habitat protection efforts.

47
2.12 Identify and study foracrmncr habitat.

Characterization of foraging habitat should include

determining species distribution and plant density,

distribution and size of foraging areas, and

threats to foraging areas. This information is

needed to determine which areas have suitable

habitat with an adequate concentration of food

plants to support viable populations.

2.2 Protect foraging habitat. Foraging habitat should be

protected as needed, based on the information collected

in Task 2.1. In areas where conflicts over food resource

use may occur (primarily with agave harvesting), the

above mentioned studies should identify the foraging

needs of the Mexican long—nosed bat, and agave not needed

for bat recovery could continue to be harvested.

2.21 Determine impact of aaave harvest on Mexican lona

—

nosed bat survival and recovery. More complete

information is needed to determine whether the

agave harvest for alcoholic beverage production has

any adverse impact on the survival and recovery of

this species. This may involve further study of

the apparent inutualistic relationship of bats and

agave (and possibly other plants), particularly the

degree to which bats depend on certain plants, and

dependence of certain plants on bats’ pollination

and/or seed dispersal.

2.22 Work with liquor industry and local producers to

protect foraging habitat. Tequila, mescal, and

pulque manufacturers should be approached to

explore ways of permitting coexistence of agave

harvesting and the bats. The goal should be to

allow a proportion of the agaves to flower every

48
year, thus providing a reliable food source for the

bats. This can probably be achieved by approaching

key people in the liquor industry and local

harvesters and explaining the role bats have played

in the evolution of agaves, and that bats depend on

the plants for their food supply, and plants depend

on bats for sexual reproduction. This alternative

might represent a feasible, relatively easy way of

restoring food supply levels for the bats. A

cooperative effort to cultivate agave may benefit

both producers and bats. Protection efforts such

as initial contacts and informational offerings,

can begin immediately. However, a more refined

approach to protecting foraging habitat is

dependent on the results of Tasks 2.1 and 4.0.

2.23 Work with agricultural users to protect foraging

habitat. The same approach as Task 2.22 should be

used with agricultural users, who might also be

reducing or eliminating bat food sources.

2.24 Ensure compliance with laws and regulations that

protect foragincr habitat where needed and

appropriate. In the United States, foraging

habitat is protected under the Endangered Species

Act if disruption of that habitat would result in

death or injury to the bats by altering essential

behavioral patterns, which include feeding.

2.25 Protect foragincr habitat throucrh other methods

including education. Local solutions to protecting

foraging habitat may be devised through or as a

result of education on the importance of bats

(particularly Tasks 1.121 and 1.111).

49
3. Determine and control other threats and limiting factors.

In addition to roasting and foraging habitat, other factors

may limit Mexican long-nosed bat populations. In a situation

where the species is not endangered, these limiting factors

might not be of concern; however, in the case of an

endangered species, they might affect the recoverability of

the species.

3.1 Identify other threats and limiting factors. Causes of

mortality such as pesticide levels, disease, predation,

parasites, pollution, interspecific roost and foraging

competition, and catastrophes should be identified and

assessed. Study of pesticide effects (e.g.,

physiological and behavioral) might be conducted in the

laboratory with a non—endangered bat species. The other

factors should be studied in the field.

3.2 Eliminate or reduce limiting factors/threats

.

Appropriate actions should be taken to eliminate or

reduce the threats found in Task 3.1 if they hinder

maintenance of viable populations.

4. Model population viability. Modeling population viability

will assist in determining delisting criteria. Information

derived as a result of these tasks will also be useful in

determining habitat protection needs, particularly in

relation to the size and configuration of habitat needed to

support the six populations that have the needed age

structure, sex ratios, and other characteristics.

4.1 Obtain demographic data. Information needed for

analyzing population viability should be collected

including reproductive success, survival, mortality

rates, population—age structure, age—specific fecundity,

and aspects of coloniality and territoriality as they

50
relate to population structure. It may take 10 years to

obtain an adequate picture of the demography of L.

nivalis. Dr. T. H. Fleming took about 10 years to

develop the life table of the relatively abundant shorttailed bat (Carollia perspicillata). Some information

may be available from Arita and Humphrey (1988), Wilson

(1988), and others. These reports should be reviewed and

compiled for location, numbers seen, sex, date, maturity,

and reproductive condition.

4.2 Determine and monitor migration times. routes. and

habitats. Information on Mexican long—nosed bat

migration will be essential to determine if the locations

and extent of the six population areas are realistic. A

possible first step is to examine existing specimen

records for information on localities, sex, date,

reproductive condition, and numbers seen. Also, radio—

tracking or uniquely marking individual (e.g., banding)

bats may be useful to study migration.

4.3 Determine levels of crenetic variability within and amoncr

populations in different aeoara~hic areas. Information

on genetic variability within and among i4exican longnosed bat populations may be needed to model population

variability. Reduced genetic variation increases the

chances of extinction due to genetic drift and inbreeding

effects. An estimate of genetic variability may alert

workers to significant reductions in genetic variation

and possible genetic bottlenecks, before genetic

variability reaches dangerously low levels. Genetic

variability may need to be sampled periodically.

4.4 Perform a population viability analysis. The data

collected in Tasks 4.1 and possibly 4.2 and 4.3 will be

used to model population viability. An analysis of

51
population vulnerability also can be done such as the one

suggested by Gilpin and Soul6 (1986). These authors

presented an approach to analyze the vulnerability of a

population based on population, environmental, and

autoecological (ecology dealing with the relationship

between organisms and their environment) parameters.

4.5 Determine size. location, and configuration of habitat

needed to suPPort viable populations. The information

collected in Tasks 1.2, 1.3, 2.11, 2.12, and 4.4 should

be used to determine areas needed for the species’ long—

term recovery. However, many protection efforts (Tasks

1.1 and 2.2) should not wait for the outcome of this

task.

52
D. Literature Cited

Alvarez, T. 1963. The recent mammals of Tainaulipas, Mexico.

University of Kansas Publications, Museum of Natural History

14:363—473.

Alvarez, T., and L. Gonz~lez-Quintero. 1970. AnAlysis polinico

del contenido gAstrico de murci6lagos Glossophaginae de

Mexico. Anales de la Escuela Nacional de Ciencias Biol6gicas

(M6xico) 18: 137—165.

Arita, H. T., and S. R. Humphrey. 1988. Revisi6n taxon6mica

de los inurci6lagos inagueyeros del g6nero Leptonycteris

(Chiroptera: Phyllostoinidae). Acta Zoologica Mexicana

(n.s.), 29:1—60.

Arita, H. T., and D. E. Wilson. 1987. Long—nosed bats and

agaves: the tequila connection. BATS 5(4):3-5.

Arizinendi, M. C., and R. Dirzo. 1992. Ladrones de n6ctar.

Oikos = (Boletin Centro de Ecologia, UNAM, Mexico) 14:1.

Arroyo-Cabrales, J., R. R. Hollander, and J. K. Jones, Jr. 1987.

Choeronycteris mexicana. Mammalian Species # 291:1—5.

American Society of Mammalogists.

Baker, R. H. 1956. Mammals of Coahuila, Mexico. Univ. Kansas

Publ., Mus. Nat. Hist. 9:125—335.

Barbour, R. W., and W. H. Davis. 1969. Bats of America.

University of Kentucky Press, Lexington, 286 pp.

Borell, A. E., and M. D. Bryant. 1942. Mammals of the Big Bend

area of Texas. Univ. California Publ. Zool. 48:1—62.

53
Brown, D. E. 1982. Biotic Communities of the American Southwest

-- United States and Mexico. Desert Plants 4(1-4):1—342.

Cockrum, E. L., and Y. Petryszyn. 1991. The long—nosed bat,

Leptonycteris: an endangered species in the southwest?

Occas. Papers Mus. Texas Tech. Univ. 142:1—32.

Davis, W. B. 1960. The mammals of Texas. Texas Game and

Fish Commission, Austin. Bulletin 27, 252 pp.

Diario Oficial. 1991. May 17:7—31.

Easterla, D. A. 1972. Status of LeptonycteriS nivalis

(Phyllostomatidae) in Big Bend National Park, Texas.

Southwestern Naturalist 17:287-292.

Easterla, D. A. 1973. Ecology of the 18 species of

Chiroptera at Big Bend National Park, Texas. Northwest

Missouri State University Studies 34:1—165.

Fleming, T. H., M. A. Homer, and M. D. Tuttle. 1990a.

Preliminary observations on the foraging behavior of the

flower—visiting bat, Leptonycteris curasoae. Bat Research

News 31(4):64.

Fleming, T. H., M. D. Tuttle, and M. A. Homer. 1990b.

Preliminary observations on the importance of Leptonycteris

curasoae as a pollinator of Sonoran desert columnar cacti.

Bat Research News 31(4):64.

Gardner, A. L. 1977. Food habits. Pp. 293-350, in Biology of

bats of the New World Family Phyllostomatidae, part II (R.

J. Baker, J. K. Jones, Jr., and D. C. Carter, eds.). Special

Publications of the Museum, Texas Tech University, Lubbock,

13:1—364.

54
Gentry, H. 5. 1972. Agaves of continental North America.

University of Arizona Press, Tucson, 670 pp.

Gillette, D. D. and J. D. Kimbrough. 1976. Chiropteran

mortality. Pp. 262-283, in About bats: a chiropteran biology

symposium (B.H. Slaughter and D.W. Walton, eds.). Southern

Methodist University Press, Dallas, Texas. 339 pp.

Gilpin, M. E., and M. E. Soul6. 1986. Minimum viable

populations: processes of species extinction. Pp. 19—34, jn:

Conservation Biology. The Science of Scarcity and Diversity

(M. E. Soul6, ed.). Sinauer Associates, Inc., Sunderland,

Mass., 548 pp.

Gomez—Poinpa, A. 1963. El genero Agave. Cact. Succulent. Hex.

8:3—28.

Hall, E. R., and W. W. Dalquest. 1963. The mammals of

Veracruz. University of Kansas Publications, Museum of

Natural History 14:165—362.

Hensley, A.P., and K. T. Wilkins. 1988. Leptonycteris nivalis.

Mammalian Species # 307:1-4. American Society of

Mammalogists.

Homer, M. A., T. H. Fleming, and H. D. Tuttle. 1990. Foraging

and movement patterns of a nectar feeding bat: Leptonycteris

curasoae. Bat Research News 31(4):81.

Howell, D. J. 1979. Flock foraging in nectar—feeding bats:

advantages to the bats and to the host plants. Amer. Nat.

114:23—49.

Howell, D. J. 1981 (unpubl.). Investigator’s annual report to

the U.S. Department of the Interior-National Park Service,

55
Big Bend N.P. Project title: Foraging behavior of

LeptonycteriS nivalis on Agave havardiana and Pollination

ecology of Agave havardiana. 3pp.

Howell, D. J. 1983 (unpubl). InvestigatOr’s annual report to

the U.S. Department of the Interior-National Park Service,

Big Bend N. P. Project title: Foraging behavior of

Leptonycteris nivalis on Agave havardiana. 15 pp.

Howell, D. J. 1988 (unpubl.). Report on LeptonyCteris nivalis

for Big Bend National Park. Population estimate for 1988,

census methods, management recommendations, general biology

and bibliography. 12 pp.

Howell, D. J., and B. s. Roth. 1981. Sexual reproduction in

agaves: The benefits of bats; the cost of seinelparous

advertising. Ecology 62:1—7.

Hoyt, R. A., J. S. Altenbach, and D. J. Hafner. in press

Observations on long-nosed bats (Leptonycteris) in New

Mexico. Southwestern Nat.

Koestner, E. J. 1941. An annotated list of mammals collected

in Nuevo Le6n, Mexico, in 1938. Great Basin Nat. 2:9-15.

Koopinan, K. F. 1981. The distributional patterns of New World

nectar-feeding bats. Ann. Missouri Bot. Gard. 68:352-369.

Kunz, T. E. 1982. Roosting ecology of bats. Pp. 1-56, ~

Ecology of bats (T. H. Kunz, ed.). Plenum Press, New York,

425 pp.

McCracken, G. F. 1989. Cave conservation: special problems of

bats. National Speleological Society Bulletin 51:47—51.

56
Mollhagen, T. 1973. Distributional and taxonoinic notes on

some West Texas bats. Southwestern Nat. 17:427—430.

Nabhan, G. P. and T. Fleming. 1993. The conservation of New

World mutualisms. Cons. Biol. 7(3):457—359.

Novick, A. 1963. Orientation in Neotropical bats. II.

Phyllostoinatidae and Desinodontidae. J. Mamin. 44:44—63.

Phillips, C. J., J. K. Jones, Jr., and F. J. Radovsky. 1969.

Macronyssid mites in oral inucosa of long—nosed bats:

occurrence and associated pathology. Science 165:1368—1369.

Powell, A. M. 1988. Trees and shrubs of Trans-Pecos Texas. Big

Bend Natural History Association, Inc. Big Bend National

Park, Texas. 536 pp.

Protection of Bat Roost Guidelines Subcommittee. 1992.

Guidelines for the protection of bat roosts. J. Mamin.

73(3) :707—710.

Reidinger, R. F., Jr. 1976. Organochlorine residues in adults

of six southwestern bat species. J. Wildl. Manage.

40(4) :677—680.

Rzedowski, J. 1978. Vegetaci6n de Mexico. Editorial Liinusa,

Mexico, D.F., 432 pp.

Sahley, C. T. 1990. Power output during commuting flight of a

nectar feeding bat, Leptonycteris curasoae. Bat Research

News 31(4).

Saussure, M. H. 1860. Mammiferes du Mexique. Revue et

Magazine du Zoologie, Series 2. 12:479—494.

57
Schmidly, D. J. 1991. The Bats of Texas. Texas A & M

University Press, College Station, Texas. 188 pp.

Thomas, D. W., and R. K. LaVal. 1988. Survey and Census

Methods. Pp. 77-89, jn Ecological and Behavioral Methods for

the Study of Bats (T. H. Kunz, ed.). Smithsonian Institution

Press, Washington, D. C., 533 pp.

Turner, D. C. 1975. The vampire bat. A field study in behavior

and ecology. Johns Hopkins University Press, Baltimore.

Tuttle, M. D. 1988. America’s neighborhood bats. Univ. of

Texas Press, Austin. 96 pp.

Tuttle, M. D. 1978. Variation in the cave environment and its

biological implications. Pp. 108-121, j.n Proceedings of the

National Cave Management Symposium. (R. Zuber, J. Chester,

S. Gilbert, and R. Rhodes, eds.) Adobe Press, Albuquerque,

New Mexico, 140 pp.

Tuttle, M. D., and D. Stevenson. 1982. Growth and survival of

bats. Pp. 105-150, i~a Ecology of bats (T. H. Kunz, ed.).

Plenum Press, New York, 425 pp.

U. S. Fish and Wildlife Service. 1988. Endangered and

threatened wildlife and plants; Determination of endangered

status for two long-nosed bats. Fed. Reg. 53(190): 38456—

38460.

Villa—R, B. 1967. Los Murcielagos de Mexico. Univ. Nac.

Autonoina Mexico. 491 pp.

Villa-R, B., and A. G. Jim6nez. 1962. Tres casos in~s de

rabia en los murci4lagos de Mexico. Anales del Instituto de

58
Biologia, Universidad Nacional Aut6noma de Mexico 32:391-395.

Walker, E. P. 1975. Mammals of the World. The Johns Hopkins

University Press, Baltimore, Maryland. 1,500 pp.

Wilson, D. E. 1979. Reproductive patterns. Pp. 317—378, jfl

Biology of bats of the New World family Phyllostomatidae,

Part III (R. J. Baker, J. K. Jones, Jr., and D. C. Carter,

Eds.). Special Publications of the Museum, Texas Tech

University. 16: 1—441.

Wilson, D. E. 1985. Status report: Leptonycteris nivalis

(Saussure) Mexican long—nosed bat. Prepared for: Office of

Endangered Species, U. S. Fish and Wildlife Service. 35 pp.

Wilson, D. E., R. A. Medellin, D. V. Lanning, and H. T. Arita.

1985. Los murci6lagos del Noreste de Mexico, con una lista

de especies. Acta Zool. Mexicana 8:1—26.

59
III. IMPLEMENTATION SCHEDULE

The following Implementation Schedule outlines actions and

estimated costs for the Mexican long—nosed bat recovery program.

It is a guide for meeting the objective (reclassification from

endangered to threatened) discussed in Part II of this Plan.

This schedule indicates task priorities, task numbers, task

descriptions, duration of tasks, the responsible agencies, and

estimated costs. These actions, when accomplished, should bring

about the reclassification of the species and protect its

habitat. It should be noted that the estimated monetary needs

for all parties involved in recovery are identified for the first

three years only. This recovery plan does not obligate any

involved agency to expend the estimated funds. Though work with

private landowners is called for in the recovery plan, private

landowners are also not obligated to expend any funds.

Task Priorities

Priority 1 -

Priority 1.

Priority 2 -

Priority 3 -

An action that must be taken to prevent

extinction or to prevent the species from

declining irreversibly in the foreseeable

future.

An action that by itself will not prevent

extinction, but is needed to carry out a

Priority 1 task.

An action that must be taken to prevent a

significant decline in species

population/habitat quality, or some other

significant negative impact short of extinction.

All other actions necessary to meet the recovery

objective.

60
Key to Acronyms used in Implementation Schedule

ECI - Bat Conservation International

FWS - U.S. Fish and Wildlife Service

ES — Ecological Services

IA — International Affairs

LE - Law Enforcement

PA - Public Affairs

MEX-G - Mexican Governmental Agencies-primarily SEDESOL

(Secretaria de Desarrollo Social)

MEX—N — Mexican Non—governmental Organizations

MEX-U - Mexican Universities/Research Entities

NBS - National Biological Survey

NMGF - New Mexico Game and Fish

NPS - National Park Service

TNC — The Nature Conservancy

TPWD - Texas Parks and Wildlife Department

61
~ICAU LONG-NOSED MT RE~ERT PLAN IWLEJEETATION SCUEDULE

PRIORITY U TASK

U TASK DESCRIPTION

TASK

DURATION

CYRS)

RESPONSIBLE PARTY COST ESTIMATES (3000)

CWPIENTS

FUS

REGION PROGRAM OTHER YEAR 1 YEAR 2 YEAR 3

11.112 Work cooperativeLy with

Landowners/managers to

estabLish protected roost

sites

continuous 9

9

ES

IA

TPW

NHGF

TNC

HEX-G

HEX-N

HEX-U

10.0

1.0

.25

.5

2.0

10.0

10.0

10.0

¶0.0

1.0

.25

.5

2.0

5.0

5.0

5.0

2.0

2.0

.25

.25

2.0

5.0

5.0

5.0

Dependent on task 1.111.

11.122 Develop and iq~tement a

program that addresses vutpire

bat issues

continuous 9

9

9

ES

IA

PA

BCI

HEX-G

HEX-N

HEX-U

5.0

2.5

2.5

10.0

10.0

10.0

10.0

5.0

2.5

2.5

5.0

5.0

5.0

5.0

5.0

2.5

2.5

5.0

5.0

5.0

5.0

In coordination with task

1.121.

Vaipire bet eradication can

be potentially devastating

to a colony.

11.13 Determine if cave gating Is

appropriate for this species

and install cave gates if

appropriate

3 9

9

ES

IA

HEX-G

HEX-N

HEX-U

10.0

10.0

10.0

5.0

5.0

10.0

10.0

10.0

S.D

5.0

Disturbance is a potentially

devastating activity.

12.22 Work with liquor industry and

local producers to protect

foraging habitat

continuous 9

9

ES

IA

ICI

HEX-G

HEX-H

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

12.23 Work with agriculturaL users

to protect foraging habitat

continuous 9

9

ES

IA

MEX-G

HEX-H

HEX-U

2.0

2.0

4.0

4.0

4.0

2.0

2.0

4.0

4.0

4.0

0~
lEXICAl LONG-NOSED MT REWVERY PLAN WLEJEUIAT IOU SCIBMJLE

PRIORITY U TASK

N TASK DESCRIPTION

TASK

DURATION

(YRS)

RESPONSIBLE PARTY COST ESTIMATES ($000)

COMMENTS

FWS

REGION PROGRAM OTHER YEAR 1 YEAR 2 YEAR 3

12.25 Protect foraging habitat

through other methods

including education

continous 2 ES

SCI

MEX-G

HEX-N

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

5.0

Using information from Tasks

2.111. 2.112. 2.113. 1 2.12.

1. 1.111 Identify landowners/managers

of roost sites and offer

information on Mexican Longnosed bats

continuous 2 ES

9 IA

TPW

NHGF

TNC

HEX-G

HEX-N

HEX-U

.25

.25

.25

.25

3.0

2.0

3.0

3.0

.25

.25

.25

.25

3.0

3.0

3.0

3.0

.25

.25

.25

.25

3.0

3.0

3.0

3.0

In coordination with task

1.112.

1.

1.

2

1.153

2.111

1.121

Develop Spanish translation of

recovery plan

c

c

continuous

2 ES

2 ES

9 IA

2 ES

9 IA

UPS

HEX-G

HEX-U

NPS

BC!

NEX-6

HEX-N

HEX-U

3.0

5.0

10.0

30

5.0

5.0

10.0

3.0

5.0

10.0

10.0

3.0

1.0

5

5.0

50

3.0

2.0

2.0

2.0

3.0

2.0

10.0

10.0

3.0

1.0

5

5.0

2.0

2.0

2.0

3.0

2.0

2.0

2.0

1.0

1.0

Possibly in cooperation with

drafter.

Inventory food plants used by

the bats

In coordination with Task

1.122.

Develop xd~lic sL~port through

a bet education program

—

—

—

1.141 Ensure couupliance with Federal

and State laws in the United

States

1.142 Ensure coopliance with

envirorguental laws in Hexico

— -

continuous 2 ES

9 LE

continuous

— - = - —

TPUD

NHGF

UPS

MEX-G

=

2.0

.25

.25

.25

3.0

LO

=

2.0

.25

.25

.25

3.0

3.0

=

2.0

.25

.25

.25

3.0

3.0

--

0~
MEXICAN LONG-NOSED MT RECOVERY PLAN NIFLEJEETAT IOU SCHEDULE

PRIORITY

A

TASK

A TASK DESCRIPTION

TASK

DURATION

CYRS)

RESPONSIBLE PARTY COST ESTIMATES ($000)

COMMENTS

FUS

REGION PROGRAM OTHER YEAR 1 YEAR 2 YEAR 3

2 1.21 DeveLop a standard method for

monitoring roosts

2 9

9

ES

IA

TPW

NPS

HEX-G

HEX-U

5.0

5.0

2.0

4.0

3.0

3.0

5.0

5.0

2.0

4.0

3.0

3.0

2 1.22 Monitor known occt~ied and

tmocc~.pied roost sites

continuous 9

9

ES

IA

NPS

HEX-G

HEX-N

HEX-U

10.0

5.0

5.0

15.0

¶0.0

15.0

5.0

5.0

1.0

10.0

8.0

10.0

Dependent on Task 1.21.

IncLudes equipment purchase

start tq money.

2 1.31 Characterize existing roosts 3 9

9

ES

IA

NPS

HEX-G

HEX-U

5.0

5.0

2.0

10.0

10.0

2.0

2.0

5.0

5.0

2.0

2.0

5.0

5.0

In cooperation with Task

1.112.

2 1.32 Predict iiere roosts might

occur

1 9

9

ES

IA

HEX-G

HEX-U

1.0

1.0

2.0

2.0

Dependent on Task 1.31.

2 1.33 Locate possible roost sites 5 9

9

ES

IA

TPW

NPS

NHGF

HEX-G

HEX-N

HEX-U

5.0

2.0

2.5

3.0

3.0

3.0

5.0

2.0

2.5

3.0

3.0

3.0

Some surveys may be

conducted immediately.

Others inust wait for

information generated by

Tasks 1.31 11.32.

Ir~.
MEXICAN ILNIG-MOSED MT EIXJVERY PLAN I~LENENTATIU SCHJULE

PRIORITY 9 TASK 9

TASK DESCRIPTION

TASK

DURATION

CYRS)

RESPONSIBLE PARTY COST ESTIMATES ($000)

COMMENTS

FUS

REGION PROGRAN OTHER

YEAR 1 YEAR 2 YEAR 3

2 2.112 Determine amo..ait of nightly

food intake per bat and per

colony

3 2 ES

9 IA

NBS

NPS

HEX-G

HEX-U

10.0

10.0

5.0

5.0

10.0

100

10.0

10.0

5.0

5.0

10.0

100

Not necessary to begin in

year 1. Can be done in

coniwiction with tasks

2.113 and 2.111.

2 2.113 Determine nightly flight

distances traveled to obtain

food

2 2 ES

9 IA

NBS

NPS

HEX-G

HEX-U

10.0

10.0

5.0

10.0

20.0

20.0

10.0

10.0

5.0

10.0

20.0

20.0

Can be done in

conjtmction with tasks

2.112 and 2.111.

Includes radio telemetry

work.

2 2.12 Identify and study foraging

habitat

4 2 ES

9 IA

NPS

MEX-G

HEX-U

10.0

10.0

S.D

10.0

10.0

10.0

10.0

5.0

10.0

10.0

Can be done in

coniwiction with and is

dependent on tasks 2.112

and 2.113.

2 2.21 Determine impact of agave

harvest on Mexican long-nosed

bat survival and recovery

3 2 ES

9 IA

SCI

HEX-G

HEX-N

HEX-U

10.0

10.0

10.0

10.0

10.0

¶0.0

Dependent on tasks 2.111,

2.112, 2.113. and 2.12.

2

I

2.24

-

Ensure compliance with laws continuous 2 ES 2.0 2.0 2.0

and regulations that protect LE .S .5 .5

foraging habitat where needed NPS 3.0 3.0 1.0

and appropriate TPW .5 .S .5

NHGF .S .5 .5

HEX-G 3.0 3.0 3.0

m.----

U,
HEX1CM LIUG-NOSED MT REO3VERY PUN I~LBENTATIOU SCHEDULE

PRIORITY 9 TASK 9

TASK DESCRIPTION

TASK

DURATION

CYRS)

RESPONSIBLE PARTY COST ESTIMATES ($000)

COMMENTS

FUS

OTHER

YEAR 1 YEAR 2 YEAR 3

REGION PROGRAM

2 4.2 Determine and monitor

migration times, routes, and

habitats

6 2 ES

MRS

HEX-G

HEX-U

HEX-N

20.0

20.0

10.0

10.0

10.0

In coordination with Task

1.33 to locate new roosts

1 Task 1.22 to monitor

known roosts.

2 4.4 Perform a population viability

analysis

2 9

9

ES

IA

HEX-G

HEX-U

Dependent on Tasks 4.1

and 4.2.

2 4.5 Determine the size, location

and configuration of habitat

needed to seq~port viable

populations

2 9

9

ES

IA

HEX-G

HEX-N

HEX-U

Completion dependent on

Task 4.4.

3 1.151 Investigate debt-for-nature

swaps

continuous 2 IA

ICI

TNC

HEX-G

HEX-N

10.0

10.0

10.0

10.0

10.0

3 1.152 Investigate enacting new

enviro.uental laws (both

Federal and State) in Mexico

continuous 9 IA

UCI

TNC

HEX-G

HEX-N

.5

5.0

1.0

5.0

5.0

.5

5.0

1.0

5.0

50

3 3.1 Identify other threats and

limiting factors

4 9

9

ES

IA

HEX-G

HEX-U

10.0

10.0

10.0

10.0

5.0

5.0

5.0

5.0

0~
lEXICAl LONG-NOSED MT RECOVERY PUN IW’LBENTATIOU SCHEDULE

PRIORITY

3

3

3

• TASK U

3.2

4.1

4.3

TASK DESCRIPTION

TASK

DURATION

(YRS)

continuous

10

4

RESPONSIBLE PARTY COST ESTIMATES ($000)

COMMENTS

FUS OTHER

MEX-G

HEX-N

HEX-U

HEX-G

HEX-U

HEX-G

HEX-U

REGION PROGRAM

2 ES

9 IA

2 ES

9 IA

2 ES

9 IA

YR 1 YR 2 YR 3

5.0

5.0

5.0

5.0

5.0

10.0

10.0

10.0

10.0

20.0

20.0

20.0

20.0

Eliminate or reduce limiting

factors/threats

20.0

20.0

20.0

20.0

Duration continuous if

significant threats have

been identified in Task

3.1.

Can be done in conjuction

with tasks 1.22. 1.33.

2.112, 2.113, 3.1, and

4.2.

Obtain demographic data

Determine levels of genetic

variability within and among

populations in different

geographic areas

Can be done in

conjw,ction with task

0~ 4.1.
IV• APPENDICES

Preliminary list of food plants

Agave sp.

Agave scabra

Agave chisosensis

Alnus sp.

Anoda sp.

Apocynaceae

Bombax

Calliandra

Ceiba

Coinpos itae

Crescentia

Datura stramoniuzn

Ficus

Grainineae

Eucalyptus

Ipomoea

Labiatae

Leguininosae

Li 1 iaceae

Malvaceae

Malvaviscus acerifolius

Myrtillocactus

Oenothera

Pinus

Sal via

Care must be taken when considering this list; noinenclatural

changes and taxonomical ambiguities have characterized this bat

species. Thus, some of the studies that report feeding

information, may include the related Leptonycteris curasoae.

For example, it is unlikely that L. nivalis feeds on pollen of

such clearly tropical species as Ceiba sp. or Ficus sp. In

addition, pollen blown from non—target flowers is likely consumed

by the bats while feeding at a bat flower. Such is certainly the

case of the pollen of the Pinus and Gramineae reported. Other

taxa listed here are also suspect such as Eucalyptus and

Oenothera.

In addition, some soft fruits are almost certainly used by

these bats; an example is the garainbullo, Myrtillocactus

geoi’netrizans.

Sources for this list are Alvarez and Gonz~lez—Quintero

(1970) and Hensley and Wilkins (1988).

68
Appendix B. Individuals and Agencies Providing Comments on the

Draft Recovery Plan for the Mexican Long—nosed Bat

.

J. Scott Altenbach, Professor, Department of Biology, University

of New Mexico, Albuquerque, New Mexico

Val Clark Beard, County Judge, County of Brewster, Texas

Donald R. Clark, Jr., Leader, Gulf Coast Research Group, National

Biological Survey, College Station, Texas

B. Lendell Cockrum, Department of Ecology and Evolutionary

Biology, University of Arizona, Tucson, Arizona

John E. Cook, Southwest Regional Director, National Park Service,

Santa Fe, New Mexico

Noreen Damude, Nongame and Urban Program, Texas Parks and

Wildlife Department, Austin, Texas

Jennifer Fowler—Propst, State Supervisor, New Mexico Ecological

Services State Office, Fish and Wildlife Service,

Albuquerque, New Mexico

David J. Hafner, Curator, Vertebrate Zoology, New Mexico Museum

of Natural History, Albuquerque, New Mexico

Peggy Homer, Zoologist, Endangered Species Program, Texas Parks

and Wildlife Department, Austin, Texas

Donna J. Howell, Ph.D., Tucson, Arizona

Norma J. Kiser, Davis Mountains Trans—Pecos Heritage Association,

Alpine, Texas

Terry C. Maxwell, Professor, Angelo State University, San Angelo,

Texas

Bonnie McKinney, Nongaine and Urban Program, Texas Parks and

Wildlife Department, Austin, Texas

Rodrigo A. Medellin, Ph.D., Centro de Ecologia, UNAM, Mexico,

D.F.

Homer E. Milford, Environmental Coordinator, Abandoned Mine Land

Bureau, Energy, Mineral and Natural Resources Department,

Santa Fe, New Mexico

Bill Montoya, Director, New Mexico Department of Game and Fish,

Santa Fe, New Mexico

69
Patricia A. Morton, Research Associate, Texas Agricultural

Experiment Station, Texas A&M University, Galveston, Texas

Merlin D. Tuttle, Executive Director, Bat Conservation

International, Austin, Texas

Matt Wagner, Nongaine and Urban Program, Texas Parks and Wildlife

Department, Austin, Texas

Kenneth T. Wilkins, Associate Professor and Director of Graduate

Studies in Biology, Baylor University, Waco, Texas

70
ADpendix C. Summary of Comments Received on the Draft Mexican

Long—nosed Bat Recovery Plan and Service Response

This draft recovery plan was available for public review and

comment on May 6, 1994. The United States Fish and Wildlife

Service (Service) requested comments by July 5, 1994. The

Service distributed over 80 copies of the draft recovery plan to

agencies, academic researchers, conservation groups, local

officials, and other interested parties in the United States and

agencies, conservation groups, academic researchers and

government officials in Mexico. In addition, 18 letters were

distributed notifying addressees that the plan was available for

public review and comment.

All comments were considered when developing the final plan. The

Service appreciates the time that each of the commenters took to

review the draft and to submit their comments.

The comments discussed below represent a composite of those

received. Comments of a similar nature are grouped together.

Substantive comments that question approach, methodology, or

financial needs called for in the draft plan, or suggest changes

to the plan, are discussed. Comments received that related to

the original listing decision that did not relate to the recovery

planning process are not discussed here. Comments regarding

simple editorial changes or providing additional biological

information were incorporated as appropriate without discussion.

Favorable, supportive comments were also received but not

summarized.

Several agencies and individuals expressed interest in

cooperating with the Service in implementing the recovery

program. The Service wishes to thank these entities for their

71
interest and contributions and looks forward to a cooperative and

successful effort to achieve the recovery objective.

All comments received are retained as a part of the

Administrative Record of recovery plan development in the Austin,

Texas, Ecological Services office.

Comment. on Recovery Plan

Aciave connection

:

Comment: The production of alcoholic beverages is a minor, not

major, threat.

Response: The effect of local harvesting of agaves for alcoholic

beverage production is not clear. The text has been changed to

reflect the uncertainty surrounding this issue. Nabhan and

Fleming (1993) refer to 100,OOOs of paniculate agave harvested in

Sonora but say nowhere is agave eliminated (see the text for a

discussion of Nabhan’ s and Fleming’s statements). (Mexican long—

nosed bats are only peripheral in Sonora). The drafter of this

recovery plan, Rodrigo Medellin, found a very low density of

flowering agave in his road—side survey. Other researchers are

also concerned about agave harvesting (Howell, pers. comm.).

Obviously, the question of the impact of alcoholic beverage

production has not been settled and consequently, several

recovery tasks address this issue.

Comment: “Virtually the entire plan is devoted to changing a

centuries old tradition in the Republic of Mexico, the gathering

of agave for fermentation. Whether or not to change this ancient

practice of gathering agave in Mexico is a matter for Mexicans to

decide.”

72
Response: The Service agrees that it is for Mexico to decide how

they implement recovery for this species. Recovery plans do not

dictate what other countries (or entities) should do. They

outline a plan for conserving endangered and threatened species.

In the case of the Mexican long-nosed bat, we realize that the

conservation of the species depends largely upon what happens in

Mexico, which is why we chose to contract with a Mexican

zoologist, Dr. Rodrigo Medellin to draft this plan. We believed

that he would be in a better position to know what the best

approach to conservation is in Mexico.

Comment: Several places in the text use the phrase “agaves and

century plants”. Century plants are agaves.

Response: This has been changed in the final recovery plan.

Also, an expanded descripion of agaves that clarifies the usages

of the two words was added.

Comment: The cultivation of agaves should be investigated.

Response: This is included in Task 2.22.

Comment: What about lechuguilla? It can increase on

deteriorated land. It is not harvested for liquor. Is it

important to L. nivalis?

Response: Lechuguilla has been noted in one instance in Mexican

long-nosed bat’s feces by Howell at BBNP in 1980. However, Donna

Howell made further comments on this situation during the public

comment period on this recovery plan. She indicated that 1980

was a drought year and the bats may have been seeking alternative

food sources. Lechuguilla does not have a flower that would

73
indicate it is bat pollinated and should not be considered an

important bat food source. The discussion of this information

was added to the final plan.

Comment: The Service needs to address the life cycle of century

plants. A discussion of the uses of Agave plants for liquor

production would be useful to understand the relationship between

bats and their food source.

and

A discussion of the differences among pulque, mescal, and

tequilla might be useful.

Response: The Service agrees. A discussion of the agave

blooming cycle and how the various alcoholic beverages are made

was added to the final plan.

Comment: How could cattle or horses destroy habitat? Cattle and

horses inadvertently provide water for bats by ranchers

maintaining “pilas” in Mexico. Neither cattle nor horses browse

agaves.

Response: Livestock are not directly implicated in destroying

long-nosed bat habitat. Rather, it is the conversion of native

habitat, including the agave plants, to cropland or pasture that

destroys or disturbs bat foraging habitat. These bats are not

thought to drink free water such as would be provided by a stock

pond.

74
Biological backcrround and threats:

Comment: The common name Mexican long—nosed bat should be

changed to greater long—nosed bat.

Response: “Mexican long—nosed bat” is the common name that was

used at the time of listing. Until the name is changed

officially, such as in a scientific article, the Service prefers

to continue using the name it was listed under. We have added

that Mexican long—nosed bats are also referred to as greater

long—nosed bats in the Background Section.

Comment: Some of the locations in Table 2 from Wilson’s data

could have been L. curasoae.

Response: The locations that Rodrigo Medellin has determined

were L. curasoae were deleted from Table 2.

Comment: The statement that Mexican long—nosed bat populations

have dramatically decreased is based on poor historical data.

Care should be used because L. curasoae has higher population

numbers than were previously thought and maybe the same is true

for nivalis.

Response: The information we have at present indicates a

decrease for L. nivalis. L. curasoae has had considerably more

attention paid to the study of its distribution and numbers,

particularly in the U.S., and appears to have a higher population

than once thought, but that information does not necessarily mean

L. nivalis is the same in that regard.

75
Comment: “Because of the species’ feeding habits, I doubt that

it would encounter much exposure to pesticides either through its

food because it feeds on nectar and pollen or through direct

exposure since it does not feed over agricultural fields as do

some insectivorous species.”

and

Aerial pesticides are usually applied during the day. Bat

flowers open at night and bats visit at night. Nectar is

unlikely to be contaminated.

Response: Reidinger (1976) did find organochlorine residues in

L. nivalis’ congener, L. curasoae. As one would suspect the

levels were lower than what was found for insectivorous bats in

the study. Although the recovery plan suggests that pesticide

effects be investigated; these studies are a lower priority than

other tasks related to more demonstrable limiting factors.

Nabhan (pers. comm.) suggests that pesticides should be

investigated because L. nivalis often forages near agricultural

fields and could be exposed to pesticides via drift onto flowers

and incidental consumption of insects.

Comment: It was suggested that “ ..the possibility of cyanide

poisoning from gold and silver mining (should) be investigated.

In California, a colony of big-eared bats was apparently

eradicated when cyanide ponds were opened nearby...”

Response: It is not thought that L. nivalis drinks free water

like other non—nectarivorous bats do.

Comment: It was suggested that “... all action regarding this

plan be held in abeyance until such time as U.S.F.W.S. has

76
performed surveys within the United States to establish some base

line information before recovery criteria are adopted.

Population estimates for Emory Cave are grossly inadequate and

totally absent for any other location in the U.S. Surveys should

also include much more detailed information regarding food plants

and habitat.”

and

Surveys should be conducted outside of BBNP, particularly at

Texas Parks and Wildlife Department land holdings.

and

More research should be done, particularly on the species’ status

and movement patterns, before the Recovery Plan is written.

Response: Research (including surveys) is often the primary need

in early stages of conservation work and provides the basis for

developing specific, effective recovery actions. Recovery

planning is an iterative process, and plans may be amended or

revised as necessary to include more specific tasks that have

been developed as a result of research.

Both the recovery strategy and recovery criteria sections contain

caveats that deal with the lack of complete knowledge about this

species and how this may require revisions in downlisting

criteria pending the outcome of recovery tasks. Recovery tasks

outline the need for surveying for L. nivalis, developing

standard methodologies, and for collecting information on food

plants and habitat. We have added TPWD to the Implementation

Schedule for Task 1.33 (locate possible roost sites).

77
Comment: “The wide swings of the long-nosed bat population in

the U.S. is another fact not addressed in the Plan. The

population is obviously responding to conditions in Mexico and

cannot be expected to recover at all in the U.S.”

and

The bat population is protected during their stay at Big Bend

National Park.

Response: The plan speculates that bats found in BBNP are

responding to conditions in Mexico that relate to blooming

phenology, impacts to agave, or population fluctuations. Habitat

in the U.S. provides this species with foraging and roosting

sites during a part of its’ seasonal “wanderings”. Because the

use of u.s. sites is seasonal, the species can not be recovered

in the U.S. alone. Instead, a series of roosting and foraging

habitat areas along their migratory path (much of which is found

in Mexico) must be protected. The Recovery Criteria and Strategy

refer to the roost at Big Bend National Park being protected as a

part of the suggested population that is located in northern

Coahuila and Texas. The Service and other U.S. entities can

undertake recovery actions within the U.S. and support recovery

efforts in Mexico. The Service is optimistic that our Mexican

counterparts will also make progress on recovery.

Comment: Caves in Mexico are owned by the government and are

considered public and protected.

Response: It is the Service’s understanding that Mexican caves

are owned by the government. However, management and protection

of this resource varies considerably and caves may or may not

actually receive protection that would extend to the bat fauna.

78
Sometimes caves are used for mining guano, dumping trash, etc.

that could be detrimental to Mexican long-nosed bats.

Comment: The incidence of rabies and other diseases communicable

to the human population must be included in Recovery Plan tasks.

Response: The incidence of rabies is discussed in the Plan.

Because these bats are nectarivores, the incidence of rabies is

extremely low. The incidence of rabies is greater in vampire

bats because they prey on mammals that could be infected with

rabies. Often because of human interference, vampire bats

supplant long-nosed bats in roosts. Thus, human health would

benefit by leaving roost sites and the native bat fauna intact.

The Service knows of no other diseases this species could

transmit to humans.

Comment: Will any effort be made to designate critical habitat?

Response: The final rule listing the Mexican long-nosed bat

addresses whether to designate critical habitat. The Service

found that designation of critical habitat was not prudent

because publication of precise descriptions of roost locations

would increase the vulnerability of these sites to vandals and

could lead to disturbance by well-meaning tourists.

Comment: Is this species active year—round?

Response: Yes, no mention of hibernation is made in the

literature.

79
Comment: The population estimates found in Tables 1 and 2 may

reflect the time of season that the roost visits were made not

the actual population estimate.

Response: Footnotes have been added to these Tables to reflect

this uncertainty.

Comment: Regarding references to Hayward and Cockrum (1971),

they were reporting on what is now known as L. curasoae.

Response: Modifications to the final recovery plan have been made

accordingly.

Comment: The statement “no Mexican long—nosed bats’ roosts have

been made unusable” is probably not true. It has been

demonstrated for other species within their range and not all

roosts have been identified. Studies (unpublished) have shown

that vandalism (burning tires) in caves have rendered Mexican

free—tailed bat roost unusable.

and

Comment: There is no direct evidence that Mexican long—nosed bat

roosts have been destroyed.

Response: We changed the wording in the final recovery plan to

“no known Mexican long—nosed bat roosts”. Many authors (see

Tuttle and Stevenson 1982 for a list of articles on roost

disturbance) have stated that bat roosts in general have

increasingly been subject to destruction by citizens killing

vampire bats, using caves as trash dumps, mining for guano, and

vandalizing roosts.

80
Comment: Some of the wildest most remote areas of North America

are found in Mexico — domestic cats climbing on the ceilings of

caves? Is this speculation?

Response: Some of the caves listed in this plan are very near

human habitations and towns where domestic and/or feral cats are

a real possibility as a predator of L. nivalis. Raccoons,

ringtails, snakes, and owls have been observed preying on bat

outflights by hanging onto the top of the cave entrance and

swiping through the emerging bat column to grab a bat and preying

on bats inside the cave by climbing the uneven surfaces of walls.

The discussion of predation was expanded in the final plan.

Comment: Several commenters indicated that the “die—off”

reported by Wilson (1985) may have been due to other factors

rather that habitat conversion because the bats would have just

moved rather than died if their food source was eliminated.

Response: The Service has taken the reference to the “die—off”

out of the final recovery plan.

Recovery objective, criteria, tasks. and iin~lementation schedule

:

Comment: “Maintained” (in the recovery criteria) may be

ambiguous and unobtainable since the number of bats present may

be more correlated with nectar phenology of plants rather than an

indication of population status (i.e., if nectar production is

high, lots of bats may be present, but if nectar production is

low 50% of the population may leave an area and it may appear

that overall population has declined when in fact they are just

absent).

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and

The suggested locations of the six populations does not take into

account the seasonal movements and possibly inultiannual

fluctuations in movements of this species.

Response: “Maintained” refers to the idea that the six

populations should remain stable throughout a 10 year period

before downlisting is considered. The monitoring program (Task

1.2) that is developed should indicate whether the populations

are stable. Viable and self-sustaining populations (not just

stable) would probably be a criteria for delisting. The

locations of the six populations that need to be protected and

maintained were made relatively large to allow for movement if

natural fluctuations in nectar production and other natural

events cause the bats to find alternate food sources. The six

areas were also designed to be distributed throughout the range

of the species.

The six populations were based on the grouping of specimen

records that Arita and Humphrey (1988) determined were L.

nival is. As discussed in the plan, if research outlined in the

recovery tasks find that there is another configuration of

populations that is more appropriate, then the criteria can be

revised. For example, tracking studies may show that there is

only one population of Mexican long—nosed bats that migrate from

central Mexico northward and then return following blooming

phenology or some other factor. The bats may migrate over areas

or have established roosts in areas where Arita and Humphrey

found no specimens records. Whether the clusters of locations

represent six distinct populations or 1 — 6 populations that move

between these areas, the thought is that by protecting these

areas the species will be provided for over a significant portion

of its range (about 80%). While several commenters criticized

82
the plan’s approach to the recovery criteria, no alternatives

were offered to improve it.

Comment: Section B, the Recovery Outline, should be deleted

because it is redundant to Section C, the Narrative Outline for

Recovery Actions.

Response: The Service and other agencies have found this concise

overview of the recovery tasks useful for summary sheets and

briefings. Also, it is helpful to some people to get a quick

overview of tasks and their relationship to one another, which is

hard to see in the Narrative Outline.

Comment: Why protect unoccupied roosts?

Response: Bats, in general, are known to recolonize abandoned

roosts when population declines have been reversed. Also, L.

curasoae seems to have reoccupied some roosts in Arizona that

were abandoned.

Comment: “The recovery criteria are implausible in the face of

the existing lack of knowledge regarding this species. To adopt

recovery criteria, such as (la) of the Plan, that attempt to

protect ‘all known roost sites and associated foraging habitat’,

puts the cart before the horse, particularly if U.S.F.W.S.

seriously expects to work cooperatively with landowners.”

Response: The Service agrees that there is a lack of knowledge

about much of this species’ biology and ecology. But to recover

the species we feel that the known roosting and foraging sites

should be protected as we are learning more about the bat,

particularly if known sites turn out to be all there is.

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Comment: A goal of protecting at least 90% of the roosting sites

might be set rather than 100% as a prerequisite for delisting.

Because this does not allow for the possibility that one site

might not be protectable.

Response: Criterion (la) to protect all roost sites has been

changed in the final plan. It is no longer included as a

criterion for downlisting but rather as part of the recovery

strategy that should be in effect until criterion 1 is

implemented. Because of the uncertainty of what constitutes a

population and how they use roost sites and how many roost sites

are available, we do not believe that the knowing destruction of

a roost site is advisable.

Comment: Are the six suggested populations separate populations

or the same bats at different times of the year? Does the entire

Mexican long—nosed bat population gather at one area during some

time of the year, then move out to different areas?

Response: What constitutes a population is not known (although

the specimens from Arita and Humphrey’s study show clumping, this

may be a result of other factors), so the Recovery Strategy

section discusses the possibilities mentioned above and states

that the six suggested population areas are tentative pending

work indicated in the Recovery Outline.

Comment: Recovery task 2.24, to ensure compliance with laws

protecting foraging habitat in the U.S., “sounds like the

destruction of one agave is illegal.”

Response: The definition of “harm” as included in the Endangered

Species Act’s regulations includes the disruption of habitat to

the extent that it kills or injures endangered wildlife by

84
altering essential behavioral patterns including feeding. It is

doubtful that the destruction of one agave would alter bat

feeding behavior.

Comment: “The actions of the Plan also are unspecific as to

country. Which of the actions are to be applied in Mexico and

which are to be applied in the United States? We believe that

the Recovery Plan developed by USFWS should pertain to the United

States only. The confusion over where recovery tasks are to take

place and where and how taxpayer dollars are to be spent are

serious flaws to this Plan.”

Response: The final plan attempts to clarify in which country

the tasks are to be performed. In general, the actions described

in this Plan apply to both Mexico and the United States unless

stated otherwise. Potential cooperators are identified in the

Implementation Schedule by country. While the USFWS is

responsible for coordinating recovery planning in the U.S., we do

not have authority to do so in Mexico. Because the majority of

this species’ range is in Mexico, the Service wanted the Plan to

be applicable to Mexico and written in a cooperative spirit.

This is one reason the Service contracted with Dr. Rodrigo

Medellin, a Mexican zoologist and bat expert, to draft the Plan.

The Implementation Schedule is a planning tool. It does not

commit any agency or any agency’s money to a task. It can be

used to prioritize tasks, estimate costs, and serve as a basis

for requesting appropriations. The tasks are implemented as time

and money are available. The work identified in the Plan for

Mexico can be funded through a number of different avenues.

Private conservation organizations or foundations both in the

U.S. and in Mexico fund work in Mexico. The Mexican government

or Mexican universities may fund research and

information/education projects. The Service contributes some

85
funds to endangered species work in Mexico through the Joint

Mexico/U.S. Committee for species that occur in both countries.

Comment: “The costs outlined to accomplish recovery goals are

excessive.”

Response: The Service attempts to estimate the costs for each

recovery task based on experience working with contractors and/or

academicians on other, analogous projects. The costs are

estimates and can vary with a number of factors such as whether

graduate students or contract biologists are employed. As noted

in the recovery plan disclaimer, costs listed are uncertain as

the feasibility of several tasks in the Plan are dependent on the

results of other tasks.

Comment: Could the presence of “gold—colored” fecal material at

cave entrances be utilized as an indicator of this species’

presence?

Response: Yes, this has been added to the monitoring tasks. It

would be particularly helpful as an indicator of presence without

creating the disturbance involved in entering a roost.

Comment: It would be helpful to break out costs by responsible

party in the executive summary.

Response: The executive summary is intended to be a j~

synopsis of the plan, including the costs of the plan. Costs are

broken down in the implementation schedule by responsible party.

Comment: National programs in Latin American countries are

rarely successful. What is needed is grassroots education in

86
communities near key roosts and foraging habitat. This is often

best facilitated through non-governmental organizations.

Response: The Service agrees. It is important to target

education to the group that is most involved (or could

potentially be involved) in bat conservation. We have added this

emphasis to the discussions on education in the Recovery Strategy

and Narrative Outline sections.

Comment: An international banding program may be useful to

determine and monitor age, migration, etc. There are some pros

and cons to banding bats, but if it is reviewed by the Service or

other scientists it might be beneficial.

Response: The Service agrees and has added this as a possible

technique in Task 4.2 (determining and monitoring movements,

times, and routes).

Comment: Factors such as disease, predation, parasites,

pollution, interspecific competition, and catastrophes are a low

priority compared to management and education.

Response: The Service agrees. This is reflected in the task

priorities given in the Implementation Schedule.

Comment: Several commenters indicated that cave gating may not

be appropriate for this species.

Response: Task 1.13 discusses cave gating as an option to

prevent disturbance to this species. Cave gating should be

investigated, and if found not harmful to the bats could be

pursued where vandalism is a problem.

87
Comment: Researchers should be extremely careful when doing

studies on Mexican long-nosed bats. Roosts have been abandoned

even though utmost care was taken in minimizing light, high

frequency sound, and time in the roost. Any research should have

direct application to recovery.

Response: The Service agrees. Several protective measures are

mentioned in the tasks involving monitoring. Also, studies

carried out in the United States that may harm an endangered

species are reviewed during the section 10(a) (1) (A) permit

process. These permits are granted for work applicable to

recovery.

Comment: Exodus counts for Leptonycteris are unreliable because

of the swirling effect of the bats actually going in and out of

the cave entrance.

Response: This problem has been mentioned in the task on

monitoring.

Comments: Several commenters stated that the protection of

foraging habitat should be a priority 1 task.

Response: The Service has reconsidered the priority level of

this task and has changed protection of foraging habitat to a

priority 1.

Comment: Foraging habitat requirements should be identified

before protecting foraging habitat.

88
Response: The studies to determine foraging habitat requirements

may take many years to complete, meanwhile habitat around known

roost sites may be destroyed or substantially modified, if not

protected. This destruction could preclude possibilities for

recovery. Therefore, possible and known food sources for L.

nivalis should be protected at least within 24 miles (40 kin) of

known roosts. This distance is based on movements documented by

Sahley (1990) and Homer ~ ~J,.(1990) and the distances bats

travel in BBNP from Mt. Emory cave to suspected foraging areas

(Easterla 1972).

Comment: Foraging habitat protection could never be accomplished

in BBNP because the tourist development is between Mt. Emory cave

and the sewage ponds that the bats need for a water source.

Response: Leptonycteris nivalis is not thought to require free

water because it is a nectarivorous species. Foraging habitat

protection can still be accomplished in this area by avoiding

and/or minimizing the impact of additional development to

possible bat foraging substrate in the Chisos Mountain basin.

Comment: The protection of foraging habitat included in Task

2.24 (ensure compliance with laws and regulations) will not be

regarded favorably in Mexico.

Response: This task was directed at protecting foraging habitat

in the United States as is discussed under Task 2.24 in the

Narrative Outline. The plan includes other strategies for

protecting foraging habitat in Mexico.

89
Comment: The past and present status of L. nivalis should be

investigated. Perhaps distribution and movements can be pieced

together with some of the existing information.

Response: We have added using specimen records to determine

movements and timing (Task 4 • 2). The present status of this

species should be determined as part of the monitoring tasks

(Tasks 1.2)

Comment: The opportunity to locate roosts exists currently.

This task should not wait for characterization of roost sites.

Response: The task that deals with locating roost sites has been

augmented to reflect this comment and the Implementation Schedule

has been changed to show that part of this task could occur in

the first three years.

Comment: Surveys for possible roost sites should be a Priority

1.

Response: The Service agrees that this should be an important

effort. But priority one tasks are tasks that must be taken to

prevent extinction or, prevent the species from declining

irreversibly in the foreseeable future. Some surveys can be

conducted almost immediately in areas where there are reasons to

believe that Mexican long—nosed bats are roosting nearby.

However, the surveys based on roost site predictions will

necessarily have to wait until roost sites are characterized and

extrapolated over the landscape.

90
Comment: Task 4.4 (in the draft plan), to determine the size,

location, and configuration of habitat needed to support viable

populations, should have a higher priority.

Response: Population and spatial (habitat) modeling can be a

valuable tool to locate sensitive parameters. Research can then

be directed to study particular factors rather than studying all

parameters. The Service agrees that sensitivity

analysis/modeling can be conducted fairly soon, without all of

the information called for in Tasks 4.0 and can provide

information instru]uental to protection efforts. Task 4.4 (in the

draft plan) was moved to a priority 2 level. However, completion

of Task 4.4 (in the draft plan) is dependent on the data

collected in other tasks. The amount of time it will take to

gather this data may be as much as 10 years. As mentioned in the

plan, it took Dr. Fleming 10 years to gather demographic data on

another bat species.

Also, the importance of studying the bats’ movements to determine

the size, location, and configuration of habitat to be protected

was emphasized and made into a task of its own (Task 4.2, given a

priority of 2.0) in the final recovery plan.

91