Annual Report

November 13, 2023

TITLE: Compilation of America Alligator Data Sets in South Florida for
Restoration Needs

**Investigator\[s\]:** Dr. Kenneth G. Rice, USGS - Biological Resources
Division

Dr. Frank J. Mazzotti, University of Florida

> Dr. Clarence L. Abercrombie, Wofford College
>
> Christa L. Zweig, University of Florida

# 

**Governmental Point of Contact: ken_g_rice@usgs.gov**

**Project Duration: Start- 10/1999 End- 12/2002**

**Project Support: CESI**

**PROJECT ABSTRACT**

Alligators have been identified as a key component of the Everglades
ecosystem. Long-term changes in alligator numbers, nesting effort,
growth, condition, and survival can be used as indicators of the health
of the Everglades marsh system. Due to their sensitivity to hydrologic
conditions, an alligator population model is underway in the ATLSS
program to evaluate restoration alternatives.

Evaluating long-term trends and developing population models require a
large amount of data collected over a number of years and a number of
locations. Information on alligator densities, nesting and growth have
been collected in south Florida since the 1950s by rangers and
researchers in Everglades National Park and Big Cypress National
Preserve, Florida Fish and Wildlife Conservation Commission personnel,
University researchers, and private consultants. Many of the most
critical data sets (those having the largest amount of data or those
from particular areas or years) are not accessible for use in evaluating
restoration alternatives or developing models. The data are not
available in a centralized, easily accessible, well-documented database.
Further, the size and scope of these data sets are not fully known.
Certainly, thousands of individual records need to be evaluated,
compiled, and entered into an appropriate database.

It is critical that these data sets are accessible to establish
restoration targets for alligator populations, develop models, and
design short and long-term monitoring tools for evaluating restoration
success.

One particular use of historical data is to make assessments of
populations in relation to restoration and water management practices in
the Everglades. Most life history characteristics are difficult to use
to assess restoration progress because it takes decades of data before
it can be used. Condition, on the other hand, can be calculated in a
relatively simple manner. Condition can be defined as the "relative
fatness of \[an animal\]. . . . it is a measure of how well that animal
is coping with its environment" (Taylor 1979). This definition is the
key to using alligators as indicators of the health of their
environment. Other parameters can be used to assess the health of a
population (nesting effort, growth rate and survival, and density and
population), but are much more data intensive.

**Objectives:**

The main objective of the study is to compile, in a format accessible to
all researchers, all data collected on alligator numbers, biology, and
ecology in south Florida. The data are required to set restoration
success criteria, provide input to models being developed to evaluate
effects of Everglades restoration on alligators, and to develop short
and long-term monitoring protocols for assessing the success of
Restoration efforts.

Specific objectives for the project include:

-   Compile a list of studies and data sets relating to alligators in
    south Florida.

-   Obtain and compile at least the highest ranking data sets.

-   Develop a standardized format for collecting and managing data on
    alligators.

-   Develop a project plan for obtaining the remaining data sets and
    producing a digital library of historic reports.

-   Use the historical data assembled above to develop a method to
    compare body condition among alligator populations in south Florida
    both spatially and temporally.

**INFORMATION NEEDS AND USES**

-   We are developing a database that contains information that will be
    available for scientific information needs of CERP (CERP Information
    Need 3070-4).

-   We are entering historical scientific data and providing access for
    CERP information needs (CERP Information Need 3070-1).

-   This study was designated a critical project for restoration of
    crocodilian populations determined by a meeting of over 40
    biologists, managers, and administrators held in Homestead in
    December, 1998.

-   Alligators are a key indicator component and are used as ecological
    attributes and measures in the Everglades Ridge & Slough, Marl
    Prairie/Rocky Glades, Big Cypress, and Mangrove Transition Zone
    Conceptual Ecosystem Models.

-   This study provides information that directly addresses the critical
    ecological pathways outlined in the Everglades Ridge & Slough
    Conceptual Ecosystem Model.

-   Specific proposed performance measures relate to the alligator such
    as reduce frequency of water dry-outs during courtship period and
    duration of below ground water depths to increase alligator nesting
    and re-establish hydrological predictability for relationship
    between peak early wet season water levels and late wet season
    levels to reduce alligator nest flooding.

-   This study allows estimation of parameters necessary for an ATLSS
    American alligator production index and an ATLSS alligator
    population model for comparison of restoration alternatives during
    implementation as outlined in South Florida Ecosystem Restoration:
    Scientific Information Needs by the Science Subgroup of the South
    Florida Ecosystem Restoration Task Force.

-   Condition is an excellent way to measure the health of an ecosystem.
    The condition factor analysis designed by this study will allow
    researchers to quickly assess the progress of restoration in the
    Everglades.

**KEY FINDINGS**

-   Interviews, questionnaires, and discussions with crocodilian
    biologists and managers in South Florida have been used to identify,
    locate, and assess availability of historical data sets.

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-   The most important datasets have been established. Several have been
    acquired and assimilated into an ACCESS database. Other databases
    have been identified and are being acquired.

-   We have conducted alligator capture and measurements for current
    alligator condition throughout the Everglades Ecosystem. Animals
    have been captured from Loxahatchee NWR, WCA 2A, WCA 2B, WCA 3A
    North, WCA 3A South, Everglades National Park (Shark Slough and
    estuarine areas), and Big Cypress National Preserve.

-   An experiment has been performed using volunteers at Loxahatchee NWR
    to evaluate the error associated with several morphometric measures
    for use in condition factor analysis.

**PROJECT DESCRIPTION**

**Purpose and Goals**

USGS-BRD and its cooperators are using a system of empirical data
collection and simulation modeling to apply information on wildlife
community patterns in guiding the restoration process. Through the
development of population simulation models based on these empirical
data, we can evaluate restoration alternatives and assess restoration
performance measures. By applying these models to restoration
alternatives and predicting population responses, we can choose the
alternatives that result in biotic characteristics that approximate
historical conditions and identify future research needs. The benefits
to restoration of this project would arise by having more confidence in
improved tools, like the ATLSS models, that are used to evaluate
alternatives for ecological effects of the Central and Southern Florida
Project Restudy, C-111 Project, and Modified Water Deliveries Plan to
Shark Slough.

Evaluating long-term trends and developing population models require a
large amount of data collected over a number of years and a number of
locations. Information on alligator densities, nesting and growth have
been collected in south Florida since the 1950s by rangers and
researchers in Everglades National Park and Big Cypress National
Preserve, Florida Game and Fresh Water Fish Commission personnel,
University researchers, and private consultants. Many of the most
critical data sets (those having the largest amount of data or those
from particular areas or years) are not accessible for use in evaluating
restoration alternatives or developing models. The data are not
available in a centralized, easily accessible, well-documented database.
Further, the size and scope of these data sets are not fully known.
Certainly, thousands of individual records need to be evaluated,
compiled, and entered into an appropriate database.

It is critical that these data sets are accessible to establish
restoration targets for alligator populations, develop models, and
design short and long-term monitoring tools for evaluating restoration
success.

Historical information provides a suite of useful life history
characteristics or population parameters (i.e. health and condition,
nesting effort, growth rate and survival, and density and population)
that can be used for restoration analysis. However, most life history
characteristics are difficult to use to assess restoration progress
because it takes decades of data before it can be used.
Condition\--defined as the "relative fatness of \[an animal\]. . . . a
measure of how well that animal is coping with its environment" (Taylor,
1979), on the other hand, can be calculated in a relatively simple
manner. Other parameters can be used to assess the health of a
population (nesting effort, growth rate and survival, and density and
population), but are much more data intensive.

**Objectives:**

-   Obtain and compile alligator data sets critical for restoration
    information needs.

-   Develop a standardized format for collecting and managing data on
    alligators.

-   Develop a project plan for obtaining the remaining data sets and
    producing a digital library of historic reports.

-   Use the historical data assembled above to develop an index that
    compares body condition among alligator populations.

# Urgency or Timelines 

This study provides access to data required for the construction of the
ATLSS American alligator population model and other evaluative tools
used during adaptive implementation of the Comprehensive Ecosystem
Restoration Plan. We also provide other timely investigations involving
comparisons of condition of alligator populations in the Everglades. The
alligator is both a keystone and indicator species in the Everglades
ecosystem. Therefore, it is critical to understand the effects of
restoration alternatives on this species and to include the alligator in
restoration alternative selection, evaluation, and monitoring.

# Effectiveness 

-   This study allows access to historical data required for ecological
    modeling and assessment of current and future status of alligator
    populations that would be otherwise inaccessible.

-   This study provides data for parameter estimation in an ongoing
    ATLSS modeling project.

-   We have produced posters and oral presentations to governmental,
    environmental (both local and international), and educational groups
    regarding the use of this data in alligator population restoration
    and management.

-   We have used graduate students and university OPS personnel for this
    study for cost effectiveness and to provide educational
    opportunities to future researchers and management personnel.

-   We provide blood and tissue samples to other ongoing projects on
    contaminant concentrations, hormonal levels, and blood chemistry of
    the alligator.

-   We have cooperated throughout this project with the Florida Fish and
    Wildlife Conservation Commission, South Florida Water Management
    District, the University of Florida, and the National Park Service
    (both Everglades National Park and Big Cypress National Preserve) to
    use equipment, personnel, and expertise for alligator capture and
    data collection especially during peak capture and monitoring
    periods at no cost to this project.

## Synopsis of Research Methods 

Alligator populations have been studied in the Everglades ecosystem
since the 1950s. Many aspects of alligator ecology have been linked to
hydrological conditions during certain periods. However, this data is
not accessible to present researchers for the comparative research and
ecological modeling required during the restoration process. The
following discussion is predicated on the need for comparisons to
current populations. Water management practices have resulted in a high
and unpredictable rate of nest flooding. Historically, maximum summer
water levels were positively correlated with water levels during
alligator nest construction. This natural predictability has been lost
(Kushlan and Jacobsen 1990). Historically, alligators were abundant in
prairie habitats of the eastern floodplain, along the edge habitats of
the central sloughs. Pre-drainage occupancy of the deep water, central
sloughs was relatively low. Marsh alligator densities are now highest in
the central sloughs and canals (Kushlan and Jacobsen 1990) and
relatively low in the edge habitats. Canal habitats contain high
concentrations of adult alligators. Nest densities are also relatively
high on levees and associated spoil islands. Less flooding of nests
occurs on these higher elevations. However, survival of young may be
very low due to a decrease in the number of alligator holes or possible
brood habitat proximal to canals. Modified hydrological conditions might
be expected to increase nesting effort, nesting success, and abundance
of alligators in the aforementioned edge habitats. There may also be a
corresponding increase in the number and occupancy of alligator holes to
serve as drought refugia.

Everglades alligators weigh less than alligators of similar size from
other parts of their range (Jacobson and Kushlan 1989, Barr 1997).
Further, maximum length is decreased, and sexual maturity is delayed
(Kushlan and Jacobsen 1990, Dalrymple 1996). Jacobsen and Kushlan's
(1989) model for growth in the Everglades of Southern Florida predicted
alligators reaching a mere 1.26 meters in 10 years and requiring at
least 18 years to reach sexual maturity. It is currently suspected that
the reason for this poor condition is a combination of low food
availability and high temperatures (Jacobson and Kushlan 1989, Dalrymple
1996, Barr 1997).

*Historical Data Sets*. \-- Managers and biologists in the field of
alligator research were consulted to determine which datasets were
critical, where they were, and the feasibility of obtaining them.
Several databases have been collected and incorporated into an ACCESS
database. Further, plans for at least three additional databases are in
preparation, including one that is in UNIVAC tape format. The tape will
be sent to a data retrieval company to recover the alligator
measurements. These numbers will have to be interpreted into actual data
and entered into the database. Three databases have been obtained as of
this report. They are survey and nesting data from A.R.M. Loxahatchee
National Wildlife Refuge, nesting data from the Florida Cooperative Fish
and Wildlife Research Unit, and Dr. Kenneth Rice's telemetry database
which consists of over 50,000 entries.

*Database design* -- The historical data is being entered into a group
of MS Access databases that are arranged in a uniform manner (Figure 1).

![](media/image1.jpeg){width="4.5in" height="3.3673611111111112in"}

Figure 1: South Florida Alligator database design

Each database consists of a data table, a metadata table, and a field
name table. The data table contains only data available from the
database. The metadata table provides a description of the project and
pertinent collection information such as GPS datum. The field name table
includes all field names and their descriptions. One Master database has
been created and consists of two tables: a Master metadata table and the
Master field name table, which compile all metadata and field name
tables into one, easily searchable database. The current Master field
name table is available in Appendix I.

*Condition*. \-- The definition of a reasonable "condition factor" is
not trivial. This is true in part because our informal evaluations are
often normative. Researchers often note that an alligator is too skinny
or a 'healthy' size, but those observations are qualitative. Even when
applied to individuals within one population these terms are not
objectively informative. In crocodilians we tend to believe that fat is
good. Amongst crocodilians it is probably true that fatter females do
produce larger clutches in a given year; however we have no strong
evidence that their lifetime productivity is higher. Furthermore, even
when our condition-assessments have been value-free, they have usually
been qualitative rather than quantitative. So long as our definitions of
condition remain unquantified, we shall confront serious difficulties
when we attempt to compare across populations.

Fisheries biologists routinely face the task of evaluating various
populations of a target species. Consequently they have been assiduous
in their quest for appropriate measures of condition (Anderson and
Gutreuter, 1983; Carlander, 1977; Gabelhouse, 1984; Wege and Anderson,
1978). Clearly this analysis has two components. The preliminary problem
is to define the condition of an individual animal. The more complex
objective is to establish a protocol for comparison across populations.

A graduate student has been employed to develop a body condition factor
analysis. Condition factor can be calculated for any organism that has a
length and weight associated with it. However, it is only an index and
must be further explained with physiological data. Condition factor in
fisheries has been backed up numerous times in the literature by
destructive total body fat analyses, so that the index is indicative of
actual body fat content. In this analysis, the important thing will be
to link alligator condition factor with a physiological factor, such as
a population parameter or blood component. The graduate student's
objectives are to:

-   Determine which standard morphometric measures exhibit the least
    measurement error.

-   Determine which condition factor index best discerns valid
    differences between populations.

-   Determine which condition factor index correlates with alligator
    population parameters or physiological state.

Current data, as well as historical data, will also be used in the
condition factor analysis. Alligators are being captured in the spring
and fall by a multi-agency team that consists of members from U.S. Fish
and Wildlife Service (USFWS), USGS-BRD, UF, and the FWC. Animals are
captured from A.R.M. Loxahatchee National Wildlife Refuge (LOX), Water
Conservation Areas 2 (WCA2A) , 3 North (WCA3AN), 3 South (WCA3AS),
Everglades National Park (ENP)---Shark Slough, and in the estuaries of
Florida Bay---ENP. A size limit of four to six feet was originally
placed on the catch because of an aging study that ran concurrently with
the catch. However, the size range has been eliminated after a
preliminary analysis (C.L. Abercrombie, pers. commun.) showed that a
larger range in total length is necessary for further study.

Alligators are captured from airboats in marshes and from motorboats in
the estuaries. They are located by spotlighting and captured with a
noose or toggle dart. Head length, snout-vent length, total length,
right hind foot length, neck girth, tail girth and chest girth are
measured to the nearest 0.1 cm. Weight is measured to the nearest 0.1
kg. They are sexed and blood was drawn for a concurrent contaminants
study. The alligators are then released, unless they are to be
sacrificed for the aging/contaminants study.

To define a preliminary condition factor and determine the health and
condition of Everglades alligators, we used least-squares regression
(LSR) to create a length-weight curve for five separate areas of south
Florida (Loxahatchee National Wildlife Refuge, Water Conservation Area
2A, Water Conservation Area 3A North, Water Conservation Area 3A South,
and Everglades National Park). LSR (SAS 1988) was run for each area to
obtain the required constants for the following ideal mass equation:

Mass = a(SVL/100)^b^,

where 'a' and 'b' are the constants for each area determined by LSR.
Snout-Vent Length (SVL) was divided by 100 to scale down mass to a more
friendly number.

We calculated ideal mass using a standard set of SVLs and the unique
equation calculated for each area. The resultant curves for all
populations (SVL vs. ideal mass) were plotted in one graph for
comparison. For the Everglades alligators, there was little difference
in condition from area to area.

Because our results were insignificant between alligators, we added a
'length vs. ideal mass' curve for the American crocodile to broaden our
comparison to crocodilians in the Everglades. The crocodile condition
curve was significantly higher than that of the Everglades gators
(Figure 2).

Figure 2: Condition comparison of Everglades alligators and Everglades
crocodiles![](media/image2.wmf)

We also obtained data on several north Florida lakes (Newnan's, Orange,
Woodruff, and Griffin) from FWC (A. Woodward, unpub. data) and one area
in South Carolina from the South Carolina Department of Natural
Resources (Santee, P. Wilkinson, unpub. data) and calculated SVL vs.
ideal mass curves for each data set using the above technique. The
Everglades curve was calculated using all data combined from the first
analysis. Everglades alligators exhibit reduced body condition in this
comparison, as their curve is below all other regions in north Florida
and South Carolina (Figure 3)

![](media/image3.wmf)

Figure 3: Condition comparison of Everglades alligators to north Florida
and South Carolina

One of the most difficult areas of condition-index projects is the
accurate determination of mass. This can be especially problematic in
remote areas and is particularly difficult for large animals (which must
be included in samples if reasonable spectra of "estimated" masses are
to be determined). We believe that the condition of a crocodilian can be
effectively represented by the animal's length-girth relationship, if
error in measurement is minimized. Possible girth measures evaluated
include neck, chest, and tail. The LSR analysis from above was run on
SVL vs. tail girth and the results are plotted below (Figure 4).

![](media/image4.wmf)

Figure 4: SVL vs. Tail Girth regression to define condition for Florida
and South Carolina populations

To determine which body measurement has the least error and would be
most appropriate for a condition factor analysis, an experiment was
performed using ten alligators captured at A.R.M. Loxahatchee National
Wildlife Refuge (LOX) and six groups of volunteers. The volunteers
consisted of LOX staff, UF employees, U.S. Geological Survey employees,
and students from Palm Beach Atlantic Community College.

Each group was given both verbal and written instructions on how to take
correct measurements. All groups measured every gator (head length,
snout-vent length, total length, neck girth, tail girth, chest girth,
and weight) and the data was entered into a database. It was analyzed
using standard deviation to determine which measurement displayed less
error from group to group. The experiment will be replicated in October
with alligator biologists to confirm the preliminary results and make
sure that the associated error was not from inexperience. The biologists
will be given the same set of instructions and the data will be treated
to the same standard deviation analysis. Preliminary results are
available in Appendix II.

# Key Results

-   A list of historic and current alligator projects and data sets has
    been compiled by sending a questionnaire to FFWCC, NPS, USFWS,
    University researchers, and private consultants who are currently or
    who have conducted research on alligators in south Florida. These
    are:

    -   Dr. James Kushlan's Everglades data.

    -   Dr. Brady Barr's food habits data.

    -   Dr. Paul Cardeilhac's blood analysis data.

    -   Everglades National Park SRF data.

    -   Dr. George Dalrymple's capture data.

    -   Dr. Franklin Percival's nesting data.

    -   Dr. Ken Rice's telemetry data.

    -   FWC's survey data.

    -   A.R.M. Loxahatchee National Wildlife Refuge's survey and nesting
        data.

    -   Dr. Frank Mazzotti and Dr. Ken Rice's current south Florida
        catch data.

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-   Four of these databases have been collected and standardized for
    storage in MS Access: Dr. Rice's telemetry, Dr. Percival's nesting
    data, Loxahatchee's survey and nesting, and the south Florida catch
    data.

-   We have conducted alligator capture and measurements for current
    alligator condition throughout the Everglades Ecosystem. Animals
    have been captured from Loxahatchee NWR, WCA 2A, WCA 2B, WCA 3A
    North, WCA 3A South, Everglades National Park (Shark Slough and
    estuarine areas), and Big Cypress National Preserve.

-   A graduate assistant has been hired to perform the condition factor
    analysis for Everglades alligators.

-   An experiment has been performed using volunteers at Loxahatchee NWR
    to determine the measurement to use in the condition factor analysis
    that involves the least error.

# 

# 

# INFORMATION PRODUCTS

**Technical Reports**

See www.fcsc.usgs.gov.

**Data & Models**

All data will be maintained at the USGS-BRD, Florida Caribbean Science
Center, Restoration Ecology Branch, University of Florida Field Station,
Davie, Florida and the University of Florida's Ft. Lauderdale Research
and Education Center in Ft. Lauderdale, Florida. All data requests
should be forwarded to Kenneth G. Rice (954-577-6305 or
ken_g_rice@usgs.gov).

# Publications and Presentations

Abercrombie, C., K. Rice, L.A. Brandt, P. Wilkinson, K.A. Hite, and F.J.

> Mazzotti. 2000. Claryfing the conundrum of crocodilian condition:
> telling thick from thin. 15th Working Meeting of the Crocodile
> Specialist Group, IUCN, Varadero, Cuba. *Poster.*

Mazzotti, F.J., C. Zweig, M. Moller, K.G. Rice, L.A. Brandt, and C.L.
Abercrombie.

> 2000\. Historical ecology of the American alligator in Greater
> Everglades Ecosystem. Greater Everglades Ecosystem Restoration
> Conference. *Poster*.

**Literature Cited and Related References**

Anderson, R.O., and S.J. Gutreuter. 1983. Length, weight, and associated
structural

> indices. Pages 283-300 *in* L.A. Nielsen and D. L. Johnson, editors.
> Fisheries techniques. American Fisheries Society, Bethesda, Maryland.

Barr, B. 1997. Food Habits of the American alligator,
[Alligator]{.underline} [mississippiensis]{.underline}, in the

southern Everglades. Unpublished Ph.D. Thesis, Univ. Miami, Florida.

Carlander, K.D. 1977. Handbook of freshwater fishery biology, volume 2.
Iowa State

University Press, Ames.

Dalrymple, G. H. 1996. Growth of American Alligators in the Shark Valley
Region of

Everglades National Park. Copeia. 1996(1): 212-216.

Gablehouse, D.W. 1984. A length-categorization system to assess fish
stocks. North

American Jorunal of Fisheries Management 4:273-285.

Jacobsen, T. and J. A. Kushlan. 1989. Growth dynamics in the American
alligator

([Alligator]{.underline} [mississippiensis]{.underline}). J. Zool.,
Lond. 219(2): 309-328.

Kushlan, J. A. and T. Jacobsen. 1990. Environmental variability and the
reproductive

success of Everglades alligators. J. Herpetol. 24(2):176-184.

SAS Institute Inc. 1988. SAS/STAT user's guide, release 6.03 edition.
SAS Institute Inc.,

Cary, NC. 1028 pp.

Taylor, J.A. 1979. The foods and feeding habits of subadult *Crocodylus
porosus* Schneider in Northern Australia. Australian Wildlife Research.
5:385-399.

Wege, J.R. and R.O. Anderson. 1978. Relative weight (Wr): a new index of
condition

> for largemouth bass. Pages 79-91 *in* G.D. Novi9nger and J.G. Dillard,
> editors. New approaches to the management of small impoundments.
> American Fisheries Society, North Central Division, Special
> Publication 5, Bethesda, Maryland.

**Appendix I**

tblMasterFieldList

**Field** **Description**

Air Temp Air temperature in C

Area Area research was done

in\--LOX,WCA2A,WCA3AN,WCA3AS,ENP-SS,EN

Area Scute Clip Area designated by a scute cut on the single

row\--11=LOX 12=WCA2A 13=WCA3AN

14=WCA3AS 15=ENP

Banded Number of banded eggs

Blastodi Number of unbanded eggs with blastodisc

Capture Date Date alligator was captured

Capture Method Method of capture\--either hand, toggle dart, snare,

or tongs

Capture Status Alligator\'s status at capture\--vigorous, etc.

Capture Time Time alligator was captured in military time

CavDepth Distance measured from top of nest to top of egg

cavity (cm)

Chest Girth Measured circumfrence of chest just posterior to

front legs in cm

ClutchWt Weight of clutch (g). Badly damaged eggs were not

weighed

CollDate Date of egg collections\--mm/dd/yy

CollTime Time (24 hour) of egg collection

Conditn Handling and transport conditions (see condition

table)

Crew Names of boat crew-First initials and full last names

Damaged Number of eggs damaged to the extent that eggs

shell membrane has been opened

Deformed Number of deformed hatchlings or late-term deaths

produced by clutch (includes \"Pelican Pouch\",

curved bodies and tails, etc.)

Deformities Any physical deformities or prominent scars

EarlMort Number of alligators that died when 1-20 days old

EmbAge4 Age of embryo upon inspection (days)

Embstat Embryo status upon initial inspection (see Embstat

table)

FemBeh Female behavior (see FemBeh table)

FemSize Estimated size of nesting female (ft)

FertDead Number of banded eggs with dead embryo on initial

check

Fertile Number of eggs with band or blastodisc

FertLive Number of banded eggs with live embryo including

killed embryos

Flooded Number of eggs totally (\>half) flooded

Habitat Type Specific habitat type. 1=Open Water 2=Forested

Wetlands 3=Shrubs/Shrub Islands 4=Mixed

Emergents 5= Sawgrass Marsh 6=Spikerush Marsh

7=Cattail Marsh 8=Water Lily/Floating Leaved Veg

9=Canal 10=Alligator Hole 11=Levee Break

12=Mangrove Pond 13=Open Slough

HachDate Date majority of eggs hatched\--mm/dd/yy

Head Length Measure dorsally from tip of snout to center of

posterior end of skull in cm

**Appendix I continued**

**Field** **Description**

Hind Foot Length Measured ventrally from the first single extended

scute posterior to heel to the anterior end of middle

toe, not including nail, in cm

Incubat Inucbation Facility (see IncubFacility table)

Infert Number of unbanded eggs (not including unbanded

eggs with blastodiscs)

InspDate Date of staging of embryo

Killed Number of live embryos killed during first

inspection

LateMort Number of alligators that died at 41 days

LiveHach Number of live hatchlings produced by clutch

including weak and deformed hatchlings that lived

Location and habitat Describes capture site and dominant vegetation

description

Maston Age left (yrs) Age determined by skeletochronology of left front

femur

Maston Age Right (yrs) Age determined by skeletochronography from front

right femur

MidMort Number of alligators that died when 21-40 days old

Moisture Moistness of nest material\--1=Dry, 2=Moist,3=Wet

Muck Depth Depth of muck in cm

Neck Girth Measured circumfrence of neck between head and

shoulders in cm

Nest Nest Number

NestDia1 Greatest nest diameter (cm)

NestDia2 Least nest diameter (cm)

NestHT Straight line distance from bottom to top of nest

\(cm\)

NestMat Predominant type of nesting material (see

NestMaterials table)

NestTemp Temperature of nest cavity (degrees C)

NonBand Number of eggs with no band

Notes Any additional information important to project

NumSet Number of eggs set after first inspection

OthTurt Number of clutches of other species of turtle eggs in

nest

ParFlood Number of eggs partially (\<half) flooded

Recapture Tag \# Tag number of recaptured animal

Recapture? A Yes/No field. Has gator been caught previous to

this capture?

RedBelly Number of clutches of redbelly turtle eggs in nest

(assume one clutch unless otherwise indicated)

Release Status Alligator status at release

Sex Male (M), Female (F), or No Data (N)

Shade Surface area of nest shaded by overhead vegetation

(%)

Status Nest status at time of collection (see nest status

table)

SV Length Measured ventrally from tip of snout to posterior

end of vent in cm

Tag Type Agency or person who issues tag

Tail Girth Measured circumfrence of tail at third scute row

posterior of rear legs in cm

Tail Scute Clip \# Number designated by scute removal on tail fork,

right fork being the hundreds digit, left is the tens,

and the singles are the scutes running down the tail

Tclutch Total number of eggs in clutch

####### Appendix I continued

**Field** **Description**

Time of Bleeding Time blood was drawn from alligator

Total Length Measured ventrally from tip of snout to tip of tail

in cm

TurtCK Check for turtle eggs note on field sheet (yes/no)

UnkFert Number of eggs with unknown fertility

UnkMort Date of death of embryo or neonate upon death

UTM Easting UTM easting coordinates in NAD83, prefaced by

17R

UTM Northing UTM northing coordinates in NAD83

Water Depth Depth of water in cm

Water Temp Water temperature in C

WeakHach Number of weak or sick hatchlings produced by

clutch

Web Tag \# Number on tag placed on web of right hind leg

Weight Total weight of animal in kg

Year Nesting Year

#######  Appendix II 

**Preliminary Results**

In all alligators, head length varied less than any other measurement
among measuring groups, straight or circumferential. However, within the
circumferential measurements, tail girth showed less measurement error
than neck or chest girth. Head length, the shortest straight length to
measure, showed less variation than other straight measurements (Table
1).

Table 1: Standard Deviation in Alligator Measurements

  -- --------- ------- --------- ------- ------- ------- ------- -----------
     HL        SVL     TL        HFL     TG      NG      CG      Weight

     0.445     1.03    0.986     1.62    1.82    2.21    4.01    4.56
  -- --------- ------- --------- ------- ------- ------- ------- -----------

HL = Head Length SVL = Snout-Vent Length TL = Total Length

HFL = Hind Foot Length TG = Tail Girth NG = Neck Girth

CG = Chest Girth