November 13, 2023

Colonel Robert A. Rowlette Jr.

District Engineer

U.S. Army Engineer District

Louisville

P.O. Box 59

Louisville, Kentucky 40201

Attn: Ms. Brenda Carter CELRL-OP-FN

Dear Colonel Rowlette:

This document transmits the U.S. Fish and Wildlife Service=s (Service)
biological opinion resulting from our review of the proposed issuance of
a Section 404 permit for the Big Monon Ditch reconstruction project
located in Pulaski, Starke and White Counties, Indiana. The biological
opinion provides the Service=s evaluation of the effects of the project
and permit issuance on the federally endangered Indiana bat (*Myotis
sodalis*), in accordance with section 7 of the Endangered Species Act
(Act) of 1973, as amended (16 U.S.C. 1531 et seq.). Your January 7, 2003
request for formal consultation was received on January 13, 2003.

This biological opinion is based on: information provided in the
September 11, 2001 biological assessment and the November 1, 2002
supplement to the biological assessment by the Monon Ditch Joint
Drainage Board and its agent, Beam, Longest and Neff; numerous telephone
conversations with your staff, the Joint Drainage Board, Beam, Longest
and Neff, and the Joint Drainage Board=s attorney (Mr. Larry Vanore of
Sommer and Barnard); field investigations; and other materials and
sources of information. A complete administrative record of this
consultation is on file at the Service=s Bloomington, Indiana Field
Office.

Sincerely,

Scott E. Pruitt

Field Supervisor

cc: Regional Director, USFWS, Twin Cities, MN (ES-TE) Attn: Jennifer
Szymanski

Marty Maupin, IDEM, Water Quality Standards Section, Indianapolis, IN

Christie Kiefer, Indiana Division of Fish and Wildlife, Indianapolis, IN

Monon Ditch Joint Drainage Board, Winamac, IN

Larry Vanore, Sommer and Barnard Attorneys at Law, Indianapolis, IN

Steve Verseman, Beam, Longest and Neff, LLC, Indianapolis, IN

USFWS, Chesterton, IN

ES: Mlitwin/812-334-4261/November 13, 2023/Big Monon-BO

2

Endangered Species Act Section 7 Consultation - Biological Opinion

Action Agency: US Army Corps of Engineers, Louisville District

Action Considered: Issuance of Section 404 permit to the Monon Ditch
Joint Drainage Board for a drainage improvement project on Big Monon
Ditch in Pulaski, Starke and White Counties, Indiana

Consultation By: Region 3, U.S. Fish and Wildlife Service

Date of Issuance: November 13, 2023

**Consultation History**

On July 14, 1998, staff of the U.S. Fish and Wildlife Service (Service)
participated in a multi-agency meeting and site inspection for a
proposed drainage improvement project on Big Monon Ditch. The meeting
was held pursuant to Indiana State law regulating State agency review of
proposed drainage maintenance projects. The Service attends such
meetings when it appears that the project may require a Section 404
permit from the U.S. Army Corps of Engineers (Corps), in order to
coordinate our review and recommendations with those of the State
natural resource agencies.

In its review letter of August 4, 1998 to the Joint Drainage Board=s
agent, Beam, Longest and Neff (BLN), the Service stated that the project
area contained suitable summer habitat for the Indiana bat (*Myotis
sodalis*). The Service=s letter pointed out that while habitat along the
project corridor is linear and narrow, the length of the project
(approximate 30 miles) indicated that there was adequate riparian
forest, small woodlots and connectivity along Big Monon Ditch and its
tributaries to provide sufficient habitat to support a nursery colony of
Indiana bats in the affected area. The Service recommended that a bat
survey be conducted in connection with the probable future need for a
Section 404 permit. In a follow-up letter of October 8, 1998 the Service
provided a set of acceptable bat survey protocols and a recommended
geographic scope of the survey (i.e. the project reach that contained
suitable summer habitat for the Indiana bat). The geographic scope was
identified as the reach from the mouth of Big Monon Ditch at Lake
Shafer, upstream to Pulaski County Road 200 North (approximately 17
miles).

A bat survey was conducted August 1-10, 1999 by Jacqueline Belwood of
the Ohio Biological Survey, with appropriate State and Federal permits.
The survey report of October 8, 1999 stated that a post-lactating female
Indiana bat was among the 262 bats captured during the survey, and
concluded that a maternity roost was likely to be present nearby. The
Indiana bat was captured at a site near the point where Big Monon Ditch
and the original Big Monon Creek channel diverge, at Pulaski County Road
1100 West. Based on the survey results the Service sent a letter to BLN
on November 2, 1999 stating a preliminary conclusion that the project as
proposed at that time would result in a take of the Indiana bat (since
virtually all habitat would be removed in the action area), and
recommending project modifications to avoid take. The recommended
modifications included avoidance of tree clearing in the best habitat at
the downstream reach of the project, coupled with reduced tree-clearing
in upstream areas.

On January 19, 2000 a coordination meeting was held between the Service,
the Joint Drainage Board and BLN to discuss options. Follow-up letters
by BLN and the Service addressed the issues discussed at the meeting,
including suggested project modifications and approaches to satisfying
requirements of the Endangered Species Act (ESA). Because it was not
certain at that time that a federal permit would be needed for the
project, participants discussed the option of applying for a Section 10
(a)(1)(B) incidental take permit under the ESA. A Section 10 permit
would have required the applicant to develop a Habitat Conservation Plan
(HCP).

In a letter of June 1, 2000, in response to additional information
provided by BLN, the Service submitted a more thorough evaluation of
where the most significant Indiana bat habitat occurs in the action
area, and revised its recommendations regarding what project
modifications would be necessary to avoid a take of the listed species.
The Service also specified additional information to assist in making a
determination of impacts and measures that would be needed to minimize
take.

On October 3, 2000 another meeting was held, including representatives
of the Joint Drainage Board, BLN, the State natural resource agencies,
the Service and the Corps of Engineers (Corps). Based on the exchange of
information at that meeting the Corps determined that it would have
jurisdiction over the entire project. In a follow-up letter of October
16, 2000 the Service indicated that formal consultation under Section 7
of the ESA would be the appropriate method of addressing ESA
requirements.

In July, 2001 BLN provided a draft Biological Assessment (BA) to the
Service for review. The Service sent a response in its letter of July
26, 2001, providing comments on the BA and recommendations concerning
additional information that would be necessary to provide an adequate
Section 7 evaluation. The final BA was completed in September, 2001 and
a copy was provided to the Service on February 25, 2002. During the
period the BA was being developed, the Service and BLN exchanged
correspondence regarding options to minimize take of Indiana bats.
Options discussed included design measures to preserve habitat, and
replacement of habitat which would be destroyed by the project. The
Service addressed these issues in its letters of September 19, November
14, and December 6, 2001.

On July 30, 2001 the Service initiated a telephone conversation with the
Corps to discuss the Section 7 consultation process for the Big Monon
Ditch project. Prior to this time, all correspondence and other
coordination reflecting informal consultation had occurred between the
Service and BLN (representing the Joint Drainage Board).[^1] On March
18, 2002 the Corps notified the Service that it was considering
authorization of the Big Monon Ditch project under a Nationwide Permit
rather than an individual permit. The Corps stated that the change in
permit type would not affect its handling of the Section 7 consultation
process.

Between April and December, 2002 the Service participated in several
coordination actions with BLN, the Joint Drainage Board and the Drainage
Board=s legal representative, Sommer and Barnard Attorneys, regarding
various aspects of project design and Section 7 consultation. This
process included several telephone conversations, a meeting with the
Joint Drainage Board and BLN on April 9, a meeting with Larry Vanore of
Sommer and Barnard on June 21, and a site inspection/meeting with all
parties on September 13. Later in September the Service was notified
that work was proposed on approximately one mile of the original Big
Monon Creek channel downstream from the point where Big Monon Ditch
diverges from the original stream channel. This portion of the project
was not covered by the BA submitted in July, 2001. On November 1 the
Service received a Supplement to the BA, dated October, 2002 for the
work on Big Monon Creek.

On November 26, 2002 the Service sent a letter to the Joint Drainage
Board addressing previous comments by Mr. Vanore and notifying them that
the Service had received sufficient information to proceed with formal
Section 7 consultation. On December 17, after a review by the Joint
Drainage Board and Mr. Vanore, copies of the letter were sent to the
Corps and other relevant parties. The Corps of Engineers responded with
a letter dated January 7, 2003 requesting the initiation of formal
consultation. The Service responded in a letter of January 23, 2003 that
it concurred with the conclusion and that formal consultation was
initiated on the date the Corp=s letter was received.

**BIOLOGICAL OPINION**

**DESCRIPTION OF THE PROPOSED ACTION**

The proposed action, as described in the BA and supplement, consists of
a drainage improvement project on approximately 29 miles of Big Monon
Ditch and one mile of the original Big Monon Creek channel downstream
from the point where Big Monon Ditch diverges. The Action Area includes
all areas along the subject waterways and tributaries where drainage
improvement work and other construction will be conducted as part of
this project contract, plus all adjacent areas which may experience
indirect effects (e.g. tree loss resulting from construction-related
root damage or from blow-down in newly exposed areas). The general
project features include clearing of riparian vegetation, excavation
within the stream channels, placement of riprap, repair or replacement
of outlet structures, and construction of temporary sediment traps.
Clearing of forested habitat within a specified reach of Big Monon Ditch
is the project component which will result in a take of Indiana bats.
The BA describes the project design as follows.

Big Monon Ditch

According to the BA the project scope is the reconstruction of Big Monon
Ditch to its original 1940 profile and cross section (which would
contain all runoff from the 100 year storm event within the ditch
channel) . The project purpose is to reduce flooding on agricultural
fields and to provide the Joint Drainage Board with better access for
future maintenance work. Of several project alternatives considered, the
selected alternative involves mechanical excavation by dragline within
the ditch throughout the entire project length. The stream/ditch section
which is of primary concern for loss of Indiana bat habitat extends from
the ditch mouth upstream to Pulaski County Road 800 South (the Aarea of
effects@). The Service concluded that project-related habitat loss in
this section would result in a take of the Indiana bat, and recommended
design alternatives which would have avoided take of the Indiana bat,
however the Joint Drainage Board rejected them as being inadequate to
fulfill the project purpose. The Service=s recommended alternatives
focused on avoidance of continuous tree clearing on both banks within
the area of effects, either by reduction in the project scope or through
use of a portable hydraulic dredge working from within the channel. The
Joint Drainage Board=s reasons for rejecting these option were: 1)
failure of the project to provide adequate flood relief if excavation is
eliminated from the area of effects; 2) the difficulty and expense of
disposal of dredge spoil from a portable dredge to sites above and away
from the steep, high forested banks; 3) the project scope=s requirement
for removal of all trees below the 100-year flood elevation to allow for
unobstructed flow; and 4) the difficulty of future maintenance work by
boat from within the channel.

Under the Joint Drainage Board=s preferred plan, all excavation work in
the area of effects would be accomplished from the east/north bank, and
all vegetation would be removed from that bank from the lowest growth
elevation up the bank slope and eastward to the landward edge of the
75-foot drainage easement. On the west/south bank, existing vegetation
would be removed from its lowest elevation of growth up the bank slope
to the 100 year flood elevation (a short distance), leaving undisturbed
all woody vegetation above and west of that point. Most of the subject
vegetation to be removed consists of mature growth of several species of
hardwood trees. The estimate in the Biological Assessment for total area
of trees to be cleared for ditch reconstruction is 68 acres of 139 total
acres within the subject stream reach, with additional tree loss from
removal of leaning trees and from construction of temporary sediment
traps as required in the State of Indiana=s floodway permit.

Upstream from County Road 800 South all work would be accomplished in
accordance with state permits (typically all excavation work would be
done from one stream bank), with all vegetation to be removed from the
75 foot easement on the work side and from both bank slopes. This would
result in the removal of virtually all woody vegetation from the Big
Monon Ditch corridor since tree growth is mostly limited to the bank
slopes in this reach, however small amounts of riparian woody vegetation
would remain along some tributaries and a few small woodlots near the
ditch corridor. This additional habitat loss is not included in the
Incidental Take Statement because: 1) No Indiana bats were captured at
several mist net sites upstream from the divergence of the old Big Monon
Creek channel at County Road 1100 West (the site of the single Indiana
bat capture); and 2) The distance from the Indiana bat capture site
upstream to County Road 800 South is approximately two miles, which is a
typical maximum distance that the Indiana bat captured during the bat
survey would have flown from the capture site.

Project features in addition to the excavation and vegetation clearing
include construction of one or more temporary sediment traps prior to
construction, removal of log jams, placement of riprap at numerous
locations, and grading and seeding of disturbed areas after work is
completed. Construction of sediment traps on some tributary stream/ditch
mouths may eliminate additional forested summer habitat for Indiana
bats, however the amount of additional habitat loss would be
insignificant compared to the habitat loss along Big Monon Ditch.

Big Monon Creek

This project component was part of the original project proposal, but
was subsequently eliminated (along with proposed work on several
tributaries), and was not included in the bat survey or the Biological
Assessment. It was reinserted into the project in early 2002, and the
FWS was notified of this fact in September, 2002. A Supplement to the
Biological Assessment to address Big Monon Creek was developed in
October, 2002 and provided to the Service in a letter dated November 1,
2002.

Work proposed for Big Monon Creek is similar in nature to the work on
Big Monon Ditch. The approximate one-mile reach of Big Monon Creek that
would be affected, although it is downstream from the divergence point,
has a higher bottom elevation than the excavated Big Monon Ditch
channel, due to a bedrock outcrop in the Big Monon Creek channel
approximately one mile south of the divergence point. Therefore the
subject one-mile reach of the Creek flows 'backward=(north) towards the
ditch during periods of normal flow. During high flows it receives water
from the upstream Big Monon Ditch channel. According to the Supplement,
proposed work on the northernmost 1000 feet and the southernmost 700
feet of the channel would consist of vegetation clearing only as needed
for equipment access, removal of leaning trees, removal of log jams, and
placement of riprap and other minor excavation. On the remaining 4100
feet of the project reach work would include complete tree clearing on
the least wooded side of the channel and excavation of the channel
bottom, in addition to the aforementioned project features.

Wooded habitat along the affected reach of Big Monon Creek is of lower
quality than that along Big Monon Ditch. The amount of Indiana bat
habitat loss from this project component has been estimated at about a
maximum of 5 acres, however this wooded corridor serves as a connection
between the bat capture site and better habitat further downstream along
Big Monon Creek.

**Conservation Measures**

The Joint Drainage Board has modified the project in the following ways
to reduce the level of take of the Indiana bat.

1\. Tree clearing along Big Monon Ditch south of CR 800 South has been
reduced by limiting clearing on the west side of the channel to areas
below the 100 year flood elevation, and by leaving suitable roost trees
on the east side where feasible without restricting work access (a
suitable roost tree is defined as a tree with a minimum dbh of 5 inches
but ideally with a dbh of at least 14 inches, either dead with
exfoliating bark or live with protruding bark such as in a shagbark
hickory).

2\. Work on several tributary streams has been eliminated from the
project, which will reduce the amount of riparian vegetation clearing.

**STATUS OF THE SPECIES** (rangewide and/or recovery unit)

The Indiana bat was officially listed as an endangered species on March
11, 1967 (Federal Register 32\[48\]:4001) under the Endangered Species
Preservation Act of October 15, 1966 (80 Stat. 926; 16 U.S.C.
668aa\[c\]). The Endangered Species Act of 1973 extended full protection
to the species. The Service has published a recovery plan (U.S. Fish and
Wildlife Service 1983) which outlines recovery actions. Briefly, the
objectives of the plan are to: (1) protect hibernacula; (2) maintain,
protect, and restore summer maternity habitat; and (3) monitor
population trends through winter censuses. The recovery plan is
currently being updated to reflect new information.

Thirteen winter hibernacula (11 caves and two mines) in six states were
designated as Critical Habitat for the Indiana bat in 1976 (Federal
Register, Volume 41, No. 187). In Indiana, two winter hibernacula are
Designated Critical Habitat, including Big Wyandotte Cave in Crawford
County and Ray=s Cave in Greene County. Neither of these caves are in
the vicinity of the proposed project.

Based on censuses taken at hibernacula in 2001, the total known Indiana
bat population is estimated to number about 382,000 bats. The most
severe declines in wintering populations have occurred in two states:
Kentucky, where 145,000 bats were lost between 1960 and 1975, and
Missouri, where 250,000 Indiana bats were lost between 1980 and 1995. In
Indiana populations dropped by 50,000 between the earliest censuses and
1980, but have rebounded to former levels in recent years. In the
2000-2001 cave census, approximately 45% of all the hibernating Indiana
bats in existence (approximately 173,000 bats) wintered in Indiana. This
represents a decline from the 1998-1999 Indiana cave census of 13,000
bats (approximately 7%) (Brack 2001).

A variety of factors have contributed to Indiana bat population declines
(U.S. Fish and Wildlife Service 1983). Sometimes their winter
hibernacula are flooded, ceilings of the hibernacula collapse, or cold
temperatures kill the bats through hypothermia. Exclusion of bats from
hibernacula through blocking of entrances, installations of gates that
do not allow for bat ingress and egress, disruption of cave air flow,
and human disturbance during hibernation have been documented causes of
Indiana bat declines. Because many known threats are associated with
hibernation, protection of hibernacula has been a management priority.

Despite the protection of most major hibernacula, population declines
have continued. Continued population declines of Indiana bats, in spite
of efforts to protect hibernacula, have led scientists to the conclusion
that additional information on summer habitat is needed (Romme et al.
1995). In addition to increased focus on summer habitat, attention is
also being directed to pesticide contamination. Insecticides have been
known or suspected as the cause of a number of bat die-offs in North
America, including endangered gray bats in Missouri (Clark et al. 1978).
The insect diet and longevity of bats also exposes them to persistent
organochlorine chemicals which may bioaccumulate in bat tissue and cause
sub-lethal effects such as impaired reproduction.

**[Description and Distribution]{.underline}**

The Indiana bat is a medium-sized bat with a head and body length that
ranges from 41 to 49 mm. It is a monotypic species that occupies much of
the eastern half of the United States, from Oklahoma, Iowa, and
Wisconsin east to Vermont, and south to northwestern Florida. The
Indiana bat is migratory, and the above described range includes both
winter and summer habitat. The winter range is associated with regions
of well-developed limestone caverns. Major populations of this species
hibernate in Kentucky, Indiana, and Missouri. Smaller winter populations
have been reported from Alabama, Arkansas, Georgia, Illinois, Maryland,
Mississippi, New York, North Carolina, Ohio, Oklahoma, Pennsylvania,
Tennessee, Virginia, and West Virginia. More than 85% of the entire
known population of Indiana bats hibernates in only nine caves.

**[Life History]{.underline}**

Generally, Indiana bats hibernate from October through April (Hall 1962;
LaVal and LaVal 1980), depending upon local weather conditions. Bats
cluster on cave ceilings in densities ranging from 300-484 bats per
square foot. Hibernation facilitates survival during winter when prey
are unavailable. However, the bat must store sufficient fat to support
metabolic processes until spring. Substantial risks are posed by events
during the winter that interrupt hibernation and increase metabolic
rates.

After hibernation ends in late March or early April, most Indiana bats
migrate to summer roosts. Female Indiana bats emerge from hibernation in
late March or early April, followed by the males. The period after
hibernation but prior to migration is typically referred to as staging.
Most populations leave their hibernacula by late April. Migration is
stressful for the Indiana bat, particularly in the spring when their fat
reserves and food supplies are low. As a result, adult mortality may be
the highest in late March and April.

Summering Indiana bats roost in trees in riparian, bottomland, and
upland forests. Roost trees generally have exfoliating bark which allows
the bat to roost between the bark and bole of the tree. Cavities and
crevices in trees also may be used for roosting. A variety of tree
species are known to be used for roosts including (but not limited to)
silver maple (*Acer saccharinum*), shagbark hickory (*Carya ovata*),
shellbark hickory (*Carya laciniosa*), bitternut hickory (*Carya*

*cordiformis*), green ash (*Fraxinus pennsylvanica*), white ash
(*Fraxinus americana*), Eastern cottonwood (*Populus deltoides*),
northern red oak (*Quercus rubra*), post oak (*Quercus stallata*) ,
white oak (*Quercus alba*), shingle oak (*Quercus imbricaria*), slippery
elm (*Ulmus rubra*), American elm (*Ulmus americana*), sassafras
(*Sassafras albidum*), and sugar maple (*Acer saccharum*) (Romme et al.
1995). At one site in southern Indiana, black locust (*Robinia
psuedoacacia*) was used extensively by roosting bats (Pruitt 1995).
Structure is probably more important than the species in determining if
a tree is a suitable roost site; tree species which develop loose,
exfoliating bark as they age and die are likely to provide roost sites.
Male bats disperse throughout the range and roost individually or in
small groups. In contrast, reproductive females form larger groups,
referred to as maternity colonies.

Maternity colonies, which may be occupied from mid-May to mid-September,
usually contain 100 or fewer adult female bats. Females each give birth
to a single young in late June or early July. Young Indiana bats are
capable of flight within a month of birth. They spend the latter part of
the summer foraging to accumulate fat reserves for the fall migration
and hibernation. Maternity colonies occupy roost sites in trees in
forested riparian, floodplain, or upland habitats (Romme et al. 1995).
Female Indiana bats exhibit strong site fidelity to summer roosting and
foraging areas, that is, they return to the same summer range annually
to bear their young. Traditional summer sites are essential to the
reproductive success of local populations. It is not known how long or
how far female Indiana bats will search to find new roosting habitat if
their traditional roost habitat is lost or degraded. If they are
required to search for new roosting habitat, it is assumed that this
effort places additional stress on pregnant females at a time when fat
reserves are low or depleted and they are already stressed from the
energy demands of migration.

Indiana bat roosts are ephemeral and frequently associated with dead or
dying trees. Most roost trees may be habitable for only 2-8 years
(depending on the species and condition of the roost tree) under natural
conditions. Gardner et al. (1991[a]{.underline}) evaluated 39 roost
trees and found that 31% were no longer suitable the following summer,
and 33% of those remaining were unavailable by the second summer. A
variety of suitable roosts are needed within a colony\'s traditional
summer range for the colony to continue to exist. Indiana bat maternity
sites generally consist of one or more primary maternity roost trees
which are used repeatedly by large numbers of bats, and varying numbers
of alternate roosts, which may be used less frequently and by smaller
numbers of bats. Bats move among roosts within a season and when a
particular roost becomes unavailable from one year to the next. It is
not known how many alternate roosts must be available to assure
retention of a colony within a particular area, but large, nearby forest
tracts appear important (Callahan 1993). In addition to having
exfoliating bark, roost trees must be of sufficient diameter. Trees in
excess of 40 cm diameter at breast height (dbh) are considered optimal
for maternity colony roost sites, but trees in excess of 22 cm dbh
appear to provide suitable maternity roosting habitat. Male Indiana bats
have been observed roosting in trees as small as 8 cm dbh.

In Illinois, Gardner et al. (1991[b]{.underline}) found that forested
stream corridors, and impounded bodies of water, were preferred foraging
habitats for pregnant and lactating Indiana bats, which flew up to 2.4
km from upland roosts to forage. Females typically utilize larger
foraging ranges than males (Garner and Gardner 1992). Bats forage at a
height of approximately 2-30 meters under riparian and floodplain trees
(Humphrey et al. 1977). They forage between dusk and dawn and feed
exclusively on flying insects, primarily moths, beetles, and aquatic
insects. Riparian habitat is occupied by Indiana bats from mid-April to
mid-September. Romme et al. (1995) cite several studies which document
that Indiana bats also forage in upland forests.

After the summer maternity period, Indiana bats migrate back to
traditional winter hibernacula. Some male bats may begin to arrive at
hibernacula as early as July. Females typically arrive later and by
September numbers of males and females are almost equal. Autumn
Aswarming@ occurs prior to hibernation. During swarming, bats fly in and
out of cave entrances from dusk to dawn, while relatively few roost in
the caves during the day. By late September many females have entered
hibernation, but males may continue swarming well into October in what
is believed to be an attempt to breed late arriving females.

Swarming is important to the life history of the bat as most copulation
occurs during this time. Females store sperm through the winter and
fertilization occurs in the spring. Females are pregnant when they
arrive at the maternity roost. Fecundity is low; female Indiana bats
produce only one young per year.

**ENVIRONMENTAL BASELINE**

The project area is in the Northern Moraine and Lake natural region of
Indiana and is underlain predominantly by sandy glacial outwash soils
(Gray 2000). In pre-settlement times the land cover was chiefly a
mixture of wetlands and oak-hickory forest with a small prairie
component. At that time it contained abundant summer Indiana bat
habitat, which was subsequently reduced during settlement and later
development. About 100 years ago the area was extensively ditched and
drained for farming and most of the remaining habitat was eliminated at
that time. Current summer habitat consists of forest blocks and
fragments and forested riparian corridors along natural streams and
streams that have been altered for agricultural drainage but have not
been maintained regularly. There are no known winter hibernaculae for
Indiana bats in the project area, and the area does not contain the
karst geological formations usually associated with caves which are used
for hibernacula.

Big Monon Creek was first channelized for agricultural drainage around
1930. In 1940 it was reconstructed and a new channel was excavated
through upland terrain from approximately Pulaski County Road 1100 West
to a new mouth at the Tippecanoe River (now Lake Shafer) (Beam, Longest
and Neff 2001). This channel relocation was considered necessary due to
a bedrock outcrop downstream from that point which prevented excavation
to a desired elevation. The entire channel from the source near North
Judson to the mouth of the new channel is now known as Big Monon Ditch.
The old Big Monon Creek channel from the point of divergence downstream
to Lake Shafer still receives flow from its own watershed, however
approximately the northern mile of channel, from the bedrock outcrop
north to the point of divergence, flows \>backwards= (north) during
normal and low flows. During flood conditions it also receives
downstream flows from Big Monon Ditch.

Suitable summer habitat in the action area is present along Big Monon
Ditch in the form of forest on the banks slopes and in the riparian
zone, from its mouth upstream for approximately four miles to the
Pulaski County line. Continuing upstream the width of the riparian
forest narrows, then becomes limited mostly to the bank slopes, and
eventually it is replaced entirely by herbaceous vegetation and crop
fields. During informal consultation the Service concluded that the
riparian forest between Pulaski County Road 800 South and the mouth of
Big Monon Ditch provides adequate habitat to support an Indiana bat
nursery colony, and that taking issues would be confined to that reach
(the area of effects). The reproductive female Indiana bat was captured
approximately two miles downstream from County Road 800 South.

Additional habitat is present along the old Big Monon Creek channel, in
isolated woodlots between the two channels (some of which are of
substantial size) and in smaller woodlot fragments in surrounding land
upstream from the diversion point. Since no telemetry studies were
performed the location of the maternity roost tree is not known. The
capture was near the diversion point of the ditch and the old channel,
and it is most likely that the nursery roost is located in or near the
best habitat, which is along Big Monon Ditch downstream from the capture
point or downstream along the old Big Monon Creek channel. A major
function of the forested Big Monon Ditch corridor is providing
connectivity among all of these forested habitat elements. Previous
research has found that reproductive female Indiana bats fly a maximum
of approximately two miles from the nursery colony to forage, however
during critical reproductive phases their flight range is less, and the
range of newly volant juveniles is considerably less (Gardner et.al.
1991b). It is possible that in environments where habitat is limited to
narrow, forested stream corridors, reproductive females may fly farther
to forage, but juveniles are limited by their lesser flying abilities.
There is no documentation of a maternity colony having a roost tree
network and foraging range which consist solely of widely scattered and
unconnected forest fragments not associated with water resources, and
connectivity is believed to be very important for maintenance of a
maternity colony. All observations of foraging area use has been
associated with riparian forest, upland forest and field edges, with no
documentation of regular foraging over open fields distant from forest
(Menzel et.al. 2001). In addition to amount and distribution of foraging
habitat, limiting factors for nursery colony distribution include the
availability of an adequate supply of roost trees. This is due to the
constant need for a network of alternate roost trees and the high
attrition rate of dead or senescent trees which are preferred for roosts
(Garner et. al.1991a, Callahan 1993).

The Biological Assessment stated that there is approximately 139 acres
of summer habitat on, along, and adjacent to the Big Monon Ditch banks
in the area of effects for the Indiana bat, as discussed previously. On
May 18, 2000 BLN provided the Service with aerial photographs depicting
the location and approximate size of all forest habitat within two miles
on either side of Big Monon Ditch. From this information the Service
concluded in a letter of June 1, 2000 that the most abundant habitat is
located along Big Monon Ditch and Big Monon Creek downstream from the
divergence point. Between the two channels, a maximum distance of
approximately two miles, there is roughly 500 acres of additional
habitat in the form of woodlots ranging up to 160 acres in size. An
additional approximate 200 acres of habitat is present in several small
woodlots east of Big Monon Ditch in the area of effects. All of these
habitat fragments are within 2 mile of at least one of the two wooded
waterways. Upstream from the divergence point there are several hundred
acres of forest fragments, but all are separated from Big Monon Ditch by
at least a mile of agricultural land. Given the extent of habitat
isolation and the increasingly meager habitat on the ditch itself, we do
not consider these habitat fragments to be useable by the subject
Indiana bat nursery colony.

Prior to the initiation of consultation on the Big Monon Ditch project
there have been no documented bat surveys in the Big Monon Ditch
watershed. Several surveys have been conducted in other areas of the
Tippecanoe River watershed with mixed results regarding capture of
Indiana bats. Since the species distribution is statewide and its summer
presence (at least within the heart of its range) is assumed to be
related to quality and amount of forest habitat rather than geographic
location, only site-specific surveys can address the possibility of its
presence. The bat survey conducted for this Section 7 consultation
process captured a total of 262 bats at 11 sites, including one
post-lactating female Indiana bat (Belwood 1999). As previously
discussed, the Indiana bat was captured near the divergence point from
the original Big Monon Creek channel; this was also the site of the most
bat captures (57 bats compared to an average of 24 bats for all sites).
This is a fairly high capture rate in view of the fact, as pointed out
in the study report, that many mist net sites were not ideal because
they lacked complete canopy closure across the ditch channel. Most bat
captures and observations occurred at mist net sites along the ditch as
opposed to sites in adjacent woodlots. The survey report concluded that
A\...the female Indiana bat was not likely to be a transient, indicating
the presence of a nearby maternity roost, most likely numbering from 25
-100 females and their young.@ The Service considers the presence of a
reproductive female or a juvenile as adequate evidence that a maternity
colony is present near the capture site. The report also concludes that
the colony would be dependent upon the ditch as a flyway and foraging
area, and would be unlikely to use surrounding agricultural fields for
those purposes. The report mentions that the ditch also supports a group
of the state-endangered evening bat (*Nycticaeus humeralis*) and a large
population of red bats (*Lasiurus borealis*), a solitary species which
roosts singly. We cannot conclude from this bat survey where the
maternity roost is, nor can we determine whether another maternity
colony is present near the action area (e.g. along the Big Monon Creek
channel or the Tippecanoe River).

Indiana bat habitat is affected by ongoing agricultural and drainage
maintenance activities in the action area. The last major reconstruction
of Big Monon Ditch by the Joint Drainage Board occurred in 1940. Given
the drainage maintenance practices typical of that period, most habitat
was probably eliminated in reconstructed segments. Since then the
aforementioned riparian habitat has become reestablished. Private
activities during the intervening time, including the removal of
woodlots and riparian trees along the ditch and tributaries, and
application of agricultural pesticides, have undoubtedly had an adverse
effect on habitat, however we are not aware of any public records of
these activities to allow an evaluation of the extent of impacts. The
abundance of red bats and the presence of the state-endangered evening
bat and an Indiana bat indicate that the reestablished riparian forest
provides substantial wildlife habitat. This is reinforced by at least
two recent records of the state-endangered river otter (*Lutra
canadensis*) along Big Monon Ditch and Big Monon Creek (Scott Johnson,
IDNR, monthly non-game mammal report, December, 2002).

**EFFECTS OF THE ACTION**

From the mouth of Big Monon Ditch at Lake Shafer upstream to
approximately the White/Pulaski County line (a distance of approximately
4 miles) the ditch corridor contains a mostly continuous mature forested
riparian border on the slope and top of the banks on both sides, ranging
150-300 feet in width (total width for both sides combined). This
riparian forest constitutes high-quality Indiana bat roosting and
foraging habitat.

From the county line upstream to central Pulaski County the tree border
is still mostly continuous but is chiefly limited to the bank slopes,
ranging from less than100 feet (downstream end) to 30-40 feet (upstream
end) in total width. From central Pulaski County upstream the riparian
vegetation is limited to scattered trees on one or both sides for a few
miles, with no woody vegetation at all for the last few upstream miles
to the project terminus in Starke County. Nearby habitat in the form of
woodlots and riparian trees along tributaries generally becomes less
abundant in an upstream direction.

Although the location of the maternity roost for the captured
reproductive female Indiana bat has not been determined, during informal
coordination the FWS concluded that the maternity roost and major
foraging area were most likely to be located downstream from the
divergence point of Big Monon Ditch on or near either the ditch or the
old Big Monon Creek channel. We further concluded that the area upstream
of Pulaski County Road 800 South constitutes marginal foraging habitat
due to the negative bat survey results (which reflect the habitat
abundance), and loss of that habitat would not adversely affect the
maternity colony. This upstream area has been excluded from the Aarea of
effects@.

The approximate one-mile project component on the old Big Monon Creek
channel contains a narrow border of young, scrubby woody vegetation. We
have concluded that take from this project component can be minimized by
implementing seasonal tree-clearing and by working from one side of the
ditch only, to maintain woody vegetation on the non-work side for
connectivity between the habitats upstream along Big Monon Ditch and
downstream along Big Monon Creek. We have included the Big Monon Creek
work in the incidental take statement because of its direct connection
with the area of effects, its proximity to the Indiana bat capture site,
and its connection to good habitat further downstream along Big Monon
Creek.

The affect of the proposed action will be to eliminate the majority of
forested habitat along Big Monon Ditch from its mouth upstream to
Pulaski County Road 800 South, including all forest from one side of the
ditch, and to degrade the forested travel corridor along that reach and
approximately one mile of Big Monon Creek south of the divergence of Big
Monon Ditch. The latter corridor is significant because we believe it is
highly likely that the maternity colony could be using both the habitat
along the ditch and that along the original stream channel. Removal of
all woody material from both sides of the Big Monon Creek segment would
result in a mile of unforested barrier between habitat blocks; this is
equivalent to approximately half of the typical maximum distance that a
reproductive female will fly from its roost during foraging. Our current
knowledge of the species indicates that individuals are less likely to
use a block of foraging habitat if crossing a large expanse of
unforested area is required to reach it (Menzel et.al. 2001).

The Service concluded that the aforementioned habitat loss would result
in a take of the Indiana bat because it would significantly reduce the
foraging and roosting habitat along Big Monon Ditch. As a result the
remaining habitat would support fewer foraging females and juveniles,
causing a reduction in size of the maternity colony and in its
reproductive success. Additionally, the reduction in forest habitat
would reduce the supply of suitable primary and alternate roost trees,
an important factor in maternity colony ecology (Callahan 1993). If
habitat loss surpasses an ecological threshhold a colony will abandon a
roosting/foraging area entirely. Futhermore, when individuals from a
colony return to a summer foraging area after hibernation their fat
reserves are very low, and energy loss associated with the need to
locate and occupy a new foraging area may result in death of some
individuals or loss of reproductive success for that year.

In summary, the action will result in take of the Indiana bat because of
the following factors:

1\. Indiana bats exhibit strong site fidelity for summer habitat and
will return to the same summer habitat area every year to bear and raise
their young. If habitat is rendered unsuitable or is inadequate the
returning females will be stressed, resulting in death or reproductive
impairment.

2\. Additional suitable habitat in the project area is very limited and
is likely to already be occupied by Indiana bats or a competing species.
The continued survival of the colony is likely dependent upon
maintaining suitable habitat within the action area of the project.

**CUMULATIVE EFFECTS**

Cumulative effects include the effects of future State, tribal, local or
private actions that are reasonably certain to occur in the action area
considered in this biological opinion. Future Federal actions that are
unrelated to the proposed action are not considered in this section
because they require separate consulta­tion pursuant to section 7 of the
Act.

We are not aware of any future State, tribal, local or private actions
that are reasonably certain to occur in the action area and would result
in adverse effects on the Indiana bat or other federally listed species.
If the ditch reconstruction proceeds as proposed it is most likely that
the action area will continue to be used for agricultural activities.

**CONCLUSION**

After reviewing the current status of the Indiana bat, the environmental
baseline for the action area, the effects of the proposed Big Monon
Ditch reconstruction project and the cumulative effects, it is the
Service\'s biological opinion that the project, as proposed, is not
likely to jeopardize the continued existence of the Indiana bat, and is
not likely to destroy or adversely modify designated critical habitat.
Critical habitat for this species has been designated in Indiana at
Wyandotte Cave and at Rays Cave, however, this action does not affect
those areas and no destruction or adverse modification of that critical
habitat will occur.

**INCIDENTAL TAKE STATEMENT**

Section 9 of the Act and Federal regulation pursuant to section 4(d) of
the Act prohibit the take of endangered and threatened species,
respectively, without special exemption. Take is defined as to harass,
harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to
attempt to engage in any such conduct. Harm is further defined by FWS to
include significant habitat modification or degradation that results in
death or injury to listed species by significantly impairing essential
behavioral patterns, including breeding, feeding, or sheltering. Harass
is defined by FWS as intentional or negligent actions that create the
likelihood of injury to listed species to such an extent as to
significantly disrupt normal behavior patterns which include, but are
not limited to, breeding, feeding or sheltering. Incidental take is
defined as take that is incidental to, and not the purpose of, the
carrying out of an otherwise lawful activity. Under the terms of section
7(b)(4) and section 7(o)(2), taking that is incidental to and not
intended as part of the agency action is not considered to be prohibited
taking under the Act provided that such taking is in compliance with the
terms and conditions of this Incidental Take Statement.

The measures described below are non-discretionary, and must be
undertaken by the Corps of Engineers so that they become binding
conditions of any permit issued to the Joint Drainage Board, as
appropriate, for the exemption in section 7(o)(2) to apply. The Corps of
Engineers has a continuing duty to regulate the activity covered by this
incidental take statement. If the Corps of Engineers (1) fails to assume
and implement the terms and conditions or (2) fails to require the Joint
Drainage Board to adhere to the terms and conditions of the incidental
take statement through enforceable terms that are added to the permit or
grant document, the protective coverage of section 7(o)(2) may lapse. In
order to monitor the impact of incidental take, the Corps of Engineers
and the Joint Drainage Board must report the progress of the action and
its impact on the species to the Service as specified in the incidental
take statement. \[50 CFR \'402.14(i)(3)\]

AMOUNT OR EXTENT OF TAKE

The Service anticipates that incidental take of the Indiana bat in terms
of numbers of animals will be difficult to detect and to quantify for
the following reason(s):

1.  The Indiana bat is small and secretive and the likelihood of finding
    dead individuals is very low.

2.  The actual location of the maternity roost and extent of foraging
    range are unknown.

3.  Unless baseline data is acquired for the size and reproductive
    success of the maternity colony there will be no way of
    quantitatively evaluating the number of individuals taken due to
    reduction in size or reproductive impairment of the colony.

However, based on the capture of a reproductive female we know that at
least one maternity colony of Indiana bats occupies the project area.
The following level of take of this species can be anticipated in terms
of loss of forested habitat, which is essential for foraging and for
providing an adequate supply of roost trees, both of which are necessary
for survival and reproduction of Indiana bats. As previously stated in
this biological opinion the Service has concluded, based on the best
available site-specific information and on our current knowledge of
Indiana bat foraging ecology, that the federal action will result in the
loss of a substantial portion of the habitat that the resident maternity
colony has been using. The Final Biological Assessment dated September,
2001 estimated that the project design would directly eliminate 68 acres
of 139 acres of forested habitat in the area of effects, through
intentional tree-clearing for drainage improvement. Additional tree
clearing may occur for construction of sediment traps and for removal of
leaning trees that would contribute to future obstructions in Big Monon
Ditch. By our estimate, unoffically confirmed by BLN, the work on Big
Monon Creek, if conducted from one side of the channel as proposed,
would require the removal of a maximum of approximately 5 additional
acres of woody vegetation (not included in the original 139 acre
estimate). This wooded riparian corridor, in addition to functioning as
foraging habitat, serves a connectivity function between the habitat
along Big Monon Ditch and the habitat further downstream along Big Monon
Creek.

The Service anticipates that the amount of take will be the permanent
loss of 75 acres of occupied summer habitat of the Indiana bat as a
result of this proposed action. The incidental take from this habitat
loss is expected to be in the form of harm and harassment to the species
by substantial reduction in the foraging and roosting habitat of a
resident maternity colony.

**EFFECT OF THE TAKE**

In the accompanying biological opinion, the Service determined that this
level of anticipated take is not likely to result in jeopardy to the
species or destruction or adverse modification of critical habitat.

**REASONABLE AND PRUDENT MEASURES**

The Service believes the following mandatory reasonable and prudent
measure(s) are necessary and appropriate to minimize take of the Indiana
bat. All of these measures concern the reach of Big Monon Ditch between
its mouth to Pulaski County Road 800 South, and an approximate one-mile
reach of the old Big Monon Creek channel included in the project. All
reasonable and prudent measures must be included in the Section 404
permit conditions for the Big Monon Ditch project.

Big Monon Ditch

1\. Perform all excavation work from the east side of the channel only.
This approach provides adequate drainage, access, and work space for
continuous excavation. Clear trees from within the east drainage
easement only to the extent necessary to provide adequate access for and
operation of excavation equipment. Limit work on the west/south bank to
tree removal (see following Measures), and installation of sediment
traps as required by IDNR.

2\. On the west side of the channel, conduct complete tree-clearing only
on the bank slope and only below the 100-year flood elevation. The
purpose of this measure is to retain all riparian forest at elevations
above the 100-year flood elevation and in the rest of the west drainage
easement (except as specified in Measure #5).

Measures 1 and 2 are described in the Biological Assessment. They will
accomplish the project goals while still retaining almost half of the
habitat and habitat connectivity within the area of effects.

3\. Leave high-quality maternity roost trees on the east side of the
ditch wherever feasible without interfering with equipment operation.
Individual trees in cleared areas may be used by Indiana bats as
alternate roosts under some circumstances. (A suitable roost tree is
defined as a tree with a minimum dbh of 5 inches but ideally with a dbh
of at least 14 inches, either dead with exfoliating bark or live with
protruding bark, such as a shagbark hickory). Identification of suitable
roost trees can be accomplished during the pre-construction field
inspection described in the following Terms and Conditions #2.

4\. Do not clear any trees during the Indiana bat summer reproductive
occupancy season (April 15 - September 15). The purpose of this measure
is to prevent the direct destruction of an occupied maternity roost,
which would result in a much higher level of take than the level
specified in this Incidental Take Statement.

5\. Limit clearing of leaning and dead trees on the west bank above the
100 year flood line to those trees which are imminently likely to fall
into the channel and create an obstruction in the near future. Trees
which may fall in the more distant future should be retained to provide
temporary foraging habitat and roost trees. Tree marking should be done
in accordance with the methods used by the Indiana Department of Natural
Resources, Division of Water, for drainage improvement projects on large
streams and small rivers. The FWS has participated in design of these
projects and is familiar with the tree-marking methods.

6\. Design and construct sediment traps to avoid or minimize tree
clearing.

Big Monon Creek

7\. Work from one side of the channel only, specifically whichever side
will result in the least tree clearing. Work may be conducted from
either side if the relative difference in amount of tree clearing
required is small.

8\. On the bank opposite the work side of the channel, remove only trees
within the channel area to be excavated, along with dead and leaning
trees as specified in measure #5 above.

Project-wide

9\. Monitor the post-construction use of the project corridor by the
resident Indiana bat maternity colony, by conducting a single follow-up
bat survey of the action area in the summer following completion of the
project. This survey will be used to determine whether the conservation
measures and reasonable and prudent measures were successful in
maintaining useable foraging habitat. The findings of the survey will
not result in any additional restrictions on the Joint Drainage Board=s
activities in the Big Monon Ditch project.

10\. Preserve all dead or injured bats of all species encountered during
construction.

TERMS AND CONDITIONS

In order to be exempt from the prohibitions of section 9 of the Act, the
Corps of Engineers and the permit applicant (Joint Drainage Board) must
comply with the following terms and conditions, which implement the
reasonable and prudent measures described above and outline required
reporting/monitoring requirements. These terms and conditions are
non-discretionary. \[Go on to list these terms and conditions, including
the requirements for monitoring, reporting, review, \[see 50 CFR
402.14(i)(3)\] and disposition of any specimens \[see 50 CFR
402.14(i)(1)(v)).\]

1\. Incorporate the above Reasonable and Prudent Measures and the
following Terms and Conditions as special conditions of any approved
Corps of Engineers permit for the Big Monon Ditch project.

2\. Prior to initiation of construction conduct a field inspection: to
mark dead and leaning trees that will be removed from the west bank of
Big Monon Ditch, in accordance with RPM #5, to identify potential roost
trees to be preserved on the east bank of Big Monon Ditch, and to
determine which side of Big Monon Creek will used for excavation
equipment. Provide the Service and the Indiana Department of Natural
Resources, Division of Fish and Wildlife (IDNR) advance notice to allow
both agencies an opportunity to participate in tree marking.

3\. Provide the Service with at least two weeks= advance notice of the
beginning of tree clearing, to allow the Service an opportunity to
observe the tree-clearing process.

4\. Notify the Service when tree-clearing has been completed.

5\. Dead bats located in the action area during construction or
monitoring activities are to be reported immediately to the Service=s
Bloomington Field Office \[(812) 334-4261\], and subsequently
transported on ice to that office. Sick or injured bats should also be
reported to the Service. No one except for researchers contracted to
conduct bat monitoring activities should attempt to handle a live bat,
regardless of its condition. The Service will make a species
identification of dead, injured or sick bats. If an Indiana bat is
identified the Bloomington Field Office will notify the appropriate
Service law enforcement office. This information on the disposition of
dead or injured bats should be incorporate into instructions provided to
project personnel and included in the construction specifications.

6\. Develop a follow-up monitoring plan for the Indiana bat maternity
colony in consultation with the Service. Monitoring must consist of a
mist-net survey following the Service=s standard protocols, and should
be conducted in the summer following the completion of the Big Monon
Ditch project. The survey must encompass the entire Aarea of effects@
(from the mouth of Big Monon Ditch upstream to Pulaski County Road 800
South), but can cover a larger area at the Corps of Engineers or the
Joint Drainage Board=s discretion. Provide the Service with advance
notice of the survey design to ensure that protocols are being followed
and that all necessary permits are obtained.

The Service believes that no more than 75 acres of Indiana bat habitat
will be incidentally taken as a result of the proposed action. This take
may occur over the life of the Section 404 permit. If the project is not
completed prior to Section 404 permit expiration and a permit renewal is
required, additional Section 7 coordination will be necessary. This
requirement is necessary because the 404 permit is the vehicle for
enforcing mandatory conditions. If the project design remains the same
and no new species are listed within the project area during the
intervening time, this Biological Opinion will still be valid and will
not have to be altered. The reasonable and prudent measures, with their
implementing terms and conditions, are designed to minimize the impact
of incidental take that might otherwise result from the proposed action.
If, during the course of the action, this level of incidental take is
exceeded, such incidental take represents new information requiring
reinitiation of consultation and review of the reasonable and prudent
measures provided. The Corps of Engineers and the permit applicant must
immediately provide an explanation of the causes of the taking and
review with the Service the need for possible modification of the
reasonable and prudent measures.

CONSERVATION RECOMMENDATIONS

Section 7(a)(1) of the Act directs Federal agencies to utilize their
authorities to further the purposes of the Act by carrying out
conservation programs for the benefit of endangered and threatened
species. The following conservation recommendations are not mandatory,
but are discretionary agency activities to minimize or avoid adverse
effects of a proposed action on listed species or critical habitat, to
help implement recovery plans, or to develop information.

1\. Acquire easements or fee title to land adjacent to or near Big Monon
Creek in the Area of Effects, to be reforested for replacement of
habitat lost as a result of the project.

2\. Conduct radio telemetry during the follow-up bat survey, if
reproductive Indiana bats or juveniles are captured, to determine the
location of the maternity roost.

In order for the Service to be kept informed of actions minimizing or
avoiding adverse effects or benefiting listed species or their habitats,
the Service requests notification of the implementation of any
conservation recommendations.

REINITIATION NOTICE

This concludes formal consultation on the action(s) outlined in the
request. As provided in 50 CFR \'402.16, reinitiation of formal
consultation is required where discretionary Federal agency involvement
or control over the action has been retained (or is authorized by law)
and if: (1) the amount or extent of incidental take is exceeded; (2) new
information reveals effects of the agency action that may affect listed
species or critical habitat in a manner or to an extent not considered
in this opinion; (3) the agency action is subsequently modified in a
manner that causes an effect to the listed species or critical habitat
not considered in this opinion; or (4) a new species is listed or
critical habitat designated that may be affected by the action. In
instances where the amount or extent of incidental take is exceeded, any
operations causing such take must cease pending reinitiation.

**LITERATURE CITED**

3D/International, Inc. 1996. Biological assessment of the master plan
and ongoing mission, U.S. Army Engineer Center and Fort Leonard Wood.
Prepared for Kansas City Corps of Engineers.

Beam, Longest and Neff. 2001. Biological assessment, reconstruction of
the Big Monon Ditch. Report to the U.S. Fish and Wildlife Service,
Bloomington, Indiana.

Beam, Longest and Neff. 2002. Supplement to Biological assessment,
reconstruction of the Big Monon Ditch. Report to the U.S. Fish and
Wildlife Service, Bloomington, Indiana.

Belwood, J.J. 1999. Bat survey of Monon Ditch, Indiana, 1-10 August
1999, final report. Report to the U.S. Fish and Wildlife Service,
Bloomington, Indiana.

Brack, V., Jr. 1983. The nonhibernating ecology of bats in Indiana with
emphasis on the endangered Indiana bat, *Myotis sodalis*. Ph.D.
dissertation, Purdue Univ., West Lafayette, Ind. 280pp.

Brack, V., T. Larkins, and S. Bell. 1987. The bats of Crane Naval
Weapons Support Center, Indiana. Report to Indiana Department of Natural
Resources, Indianapolis.

Brack, V.and K. Dunlap. 2001. A 2000-2001 winter survey for Indiana bats
(*Myotis sodalis*) in hibernacula of Indiana.

Callahan, E.V., III. 1993. Indiana bat summer habitat requirements. M.S.
Thesis. University of Missouri Columbia. 84pp.

Clark, D.R., Jr., R.K. LaVal, and D.M. Swineford. 1978. Dieldrin-induced
mortality in an endangered species, the gray bat (*Myotis grisescens*).
Science 199:1357-1359.

Gardner, J.E., J.D. Garner, and J.E. Hofmann. 1991[a]{.underline}.
Summer roost selection and roosting behavior of *Myotis sodalis*
(Indiana bat) in Illinois. Unpublished report, Illinois Natural History
Survey, Section of Faunistic Surveys and Insect Identification. 51pp.

Gardner, J.E., J.D. Garner, and J.E. Hofmann. 1991[b]{.underline}.
Summary of Myotis *sodalis* summer habitat studies in Illinois: with
recommendations for impact assessment. Unpublished report prepared for
the Indiana/Gray Bat Recovery Team Meeting, Columbia, Mo. Illinois
Natural History Survey, Section of Faunistic Surveys and Insect
Identification. 28pp.

Garner, J.D, and J.E. Gardner. 1992. Determination of summer
distribution and habitat utilization of the Indiana bat (*Myotis
sodalis)* in Illinois. Final Report: Project E-3. Endangered Species Act
Section 6 Report, Illinois Dept. of Conservation.

Gray, H. 2002. Physiographic divisions of Indiana. Indiana Geological
Survey Special Report 61. Indiana University, Bloomington, Indiana.

Hall, J. 1962. A life history and taxonomic study of the Indiana bat,
(*Myotis sodalis*). Reading Public Museum and Art Gallery Publication
12:1-68.

Humphrey, S.R., A.R. Richter, and J.B. Cope. 1977. Summer habitat and
ecology of the endangered Indiana bat, *Myotis sodalis*. Journal of
Mammalogy 58:334-346

Kurta, A., K.J. Williams, and R. Mies. 1996. Ecological, behavioral, and
thermal observations of a peripheral population of Indiana bats (*Myotis
sodalis*). Pages 102-117 [in]{.underline} R.M.R. Barclay and R.M.
Brigham, eds. Bats and Forests Symposium. Research Branch, British
Columbia Ministry of Forests, Working Paper 23:1-292. Victoria, British
Columbia, Canada.

LaVal, R.K. and M.L. LaVal. 1980. Ecological studies and management of
Missouri bats, with emphasis on cave-dwelling species. Missouri Dept. of
Conservation Terrestrial Series 8:1-53.

Menzel, M.A. et.al. 2001. Review of the forest habitat relationships of
the Indiana bat (*Myotis sodalis*). U.S. Department of Agriculture,
Forest Service General Technical Report NE-284, Newtown Square,
Pennsylvania.

Montgomery Watson. 1997. Final survey of bat species: Atterbury Reserve
Forces Training Area, Edinburgh, Indiana. Report prepared for the
Military Dept. of Indiana: Contract #DAHA90-94-0013.

Pruitt. L. 1995. Summary of Jefferson Proving Ground bat surveys:
1993-1995. U.S. Fish and Wildlife Service, Bloomington Field Office,
Unpublished report. 5pp.

Romme, R.C., K. Tyrell, and V. Brack, Jr. 1995. Literature summary and
habitat suitability index model: components of summer habitat for the
Indiana bat, *Myotis sodalis*. Report to Indiana Department of Natural
Resources, Federal Aid Project E-1-7, Study No. 8. 38pp.

Smith, W.B. and M.F. Golitz. 1988. Indiana forest statistics, 1986.
North Central Forest Experiment Station Resource Bulletin NC-108. 139pp.

Tyrell, K. and V. Brack, Jr. 1990. A survey for the endangered Indiana
bat (*Myotis sodalis*) on Hoosier National Forest, Indiana. A report to
the Hoosier National Forest and the Indiana Department of Natural
Resources. 93pp.

U.S. Fish and Wildlife Service. 1983. Recovery plan for the Indiana bat.
Washington, D.C. 80pp.

[^1]: During an April 2, 2001 telephone conversation with BLN, the Corps
    had indicated that it would not request to review the draft BA.