Record Total Lengths of the American Alligator in Florida
Arnold M. Brunell1,*, J. Patrick Delaney1, Richard G. Spratt2, Dwayne A. Carbonneau3,
and Jason E. Waller3
Abstract - Claims of unusually large crocodilians are often questionable because of the lack of physical
evidence and a verification process. We report on the longest Alligator mississippiensis (American
Alligator) that has been officially measured in Florida. The state record for the longest alligator is
435.5 cm (14 ft 3.5 in) and is only the third specimen in Florida known to exceed 426.5 cm (14 ft).
Discussion is presented about the measurements taken, techniques used to obtain the measurements,
and personnel required for officially recognizing record specimens. We emphasize the importance of
having qualified biologists verify measurements using standardized techniques and recommend that
other states within the alligator’s range develop a protocol similar to Florida’s for measuring exceptionally
large alligators.
The general public typically is keenly interested in knowing about the largest attainable
size of wildlife species such as Alligator mississippiensis Daudin (American Alligator). Yet
questionable records of large specimens are commonly presented as fact and provided for
public reference. For instance, Conant and Collins (1998) report that the record total length
(TL) for an American Alligator is 584 cm (19 ft 2 in), as reported by McIlhenny (1935).
However, Woodward et al. (1995) noted that this report lacked any tangible evidence (e.g.,
skull) or corroborating documentation to support the claim. Woodward et al. (1995) also
presented an argument, based on estimated TLs from the largest known existing skulls, that
an alligator of that length was highly unlikely. For these reasons, the Florida Fish and Wildlife
Conservation Commission (FWC) recognizes lengths of exceptionally large alligators
only in the cases where an FWC biologist has collected and recorded size data in accordance
with standardized techniques.
Alligators mostly inhabit freshwater systems and occur in warm temperate regions,
unlike most other crocodilians, which occur in subtropical or tropical regions (Mazzotti
and Brandt 1994). Alligators are found throughout Florida, as well as several other states
in the southeastern United States. Although alligators were once classified as federally
endangered, their populations have rebounded such that they are now legally hunted in
many states (David et al. 1996, Dutton et al. 2002, Rhodes 2002). Alligators have been
legally harvested within Florida since 1977, and annual harvests average approximately
15,000–20,000 /yr. Of these, approximately 7000 are from the statewide harvest on public
waterways, 9000 are harvested as nuisance alligators (i.e., alligators perceived as being a
threat to people, pets, or livestock on private or public waterways), and another 4000 alligators
from managed harvests on privately-owned wetlands (Florida Fish and Wildlife
Conservation Commission 2011).
When the FWC receives a report of an exceptionally large alligator, it assigns
biologists the task of measuring it. Relying on trained biologists ensures that the measurements
are performed in a standardized way, and such consistency is the standard for
measuring trophy game. For example, all of the records recognized by the Boone and
Crockett Club must be validated by one of its Official Measurers (Buckner and Reneau
2009). Boone and Crockett Official Measurers must have successfully completed the
1Florida Fish and Wildlife Conservation Commission, 601 W. Woodward Avenue, Eustis, FL 32726.
2Florida Fish and Wildlife Conservation Commission, 8864 C.R. 247, Lake Panasoffkee, FL 33538.
3Florida Fish and Wildlife Conservation Commission, 1239 S.W. 10th Street, Ocala, FL 34471. *Corresponding
author - Arnold.Brunell@myFWC.com.
Notes of the Southeastern Naturalist, Issue 12/4, 2013
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A.M. Brunell, J.P. Delaney, R.G. Spratt, D.A. Carbonneau, and J.E. Waller
club’s training workshop for scoring all of the trophy categories recognized by the club.
Furthermore, Boone and Crockett world records must be validated by panel judges
who have been selected by the Records Committee, which oversees the record-keeping
efforts for the club. The FWC administers the Florida Buck Registry, a program for
Florida hunters that is similar to Boone and Crockett’s program for scoring and validating
trophy deer (D. Francis and A. Kane, FWC, Quincy and Panaman City, FL, pers.
comm.). Both programs maintain the integrity of their records by accepting only standardized
measurements taken by officially trained measurers.
To ensure standardization, the FWC developed a protocol for measuring alligators that
follows the generally accepted convention in North America for measuring reptiles and
amphibians from Conant and Collins (1998), which uses a straight-line distance for length
and considers the cloaca (i.e., vent) to be part of the trunk instead of the tail. Straight-line
measurements are taken with a steel measuring tape, and girth measurements are taken
with a nylon measuring tape. English units are commonly used for reporting sizes of alligators
in the United States, and English and metric measuring tapes are sometimes used
interchangeably. When converting from English to metric, we round to the nearest 0.5 cm.
This protocol was initially used in Florida for research conducted between 1981 and 1990
to collect morphometric data from more than 3000 alligators harvested during experimental
alligator harvests (Woodward et al. 1992), and has continued to serve as FWC’s standardized
guidelines for measuring alligators. Measurements included in the FWC protocol for
record alligators are TL, snout–vent length (SVL), head length (HL), tail girth (TG), and
weight (WT).
Total length is the straight-line measurement from the tip of the snout to the tip of the tail
(Fig. 1). This is best accomplished by placing marks on a flat, level surface at the two extremes
and measuring the distance between them after the alligator has been removed. Tail
injuries that affect TL should be noted with an estimation of the amount missing. It might
be difficult or impossible in these cases to know what the TL would have been without the
injury, but this information can be of interest for future reference. Although over-the-back
(dorsal) measurements of TL are commonly used when working with live alligators in confined
spaces, such as on a small boat, we use the straight-line method for record alligators
due to concerns that greater length and greater variation could result from following the
contours of the alligator ’s body (Britton et al. 2012).
Snout–vent length is the straight-line distance from the tip of the snout to the posterior
margin of the cloaca (Fig. 2). This measurement can be taken using a metal tape with the
animal lying on its back on a flat surface. The metal tape can help ensure that a straight-line
measurement is obtained. Snout–vent length can also be measured in a fashion similar to TL
while the animal is lying on its belly on a flat, level surface. Unlike measuring TL, however,
the tail must be lifted enough to mark the posterior margin of the cloaca on the flat surface.
In crocodilians, SVL is highly correlated with TL and therefore can serve as an indicator of
Figure 1. The standard total length (TL) measurement of an American Alligator is the straight-line
distance from the tip of the snout to the tip of the tail.
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TL when the distal end of the tail is missing as a result of past injury (Chabreck and Joanen
1979; Platt et al. 2009, 2011; Webb and Messel 1978).
Variations in the methods used to determine HL (or skull length) in crocodilians are
potential sources of confusion. For instance, HL has been defined as the distance from the
tip of the snout to the quadrates (Dodson 1975), to the posterior edge of the supraoccipital
plate (Eaton and Link 2011; Erickson et al. 2003; Platt et al. 2009, 2011), and to the posterior
surface of the occipital condyle (Verdade 2000). FWC measures HL as the straight
center-line measurement from the tip of the snout to the medial posterior margin of the cranial
platform, or parietal bone, parallel to the dorsal surface of the skull (Fig. 3). Calipers
or a metal tape should be used to ensure that a straight-line measurement is obtained at the
appropriate angle. This method of measuring HL is consistent with “dorsal cranial length
A” which was recently reported for a record-size Crocodylus porosus Schneider (Estuarine
Crocodile), the largest crocodilian ever placed in captivity (Britton et al. 2012). Head length
is important because it is highly correlated with TL (Platt et al. 2009, 2011; Woodward et al.
1995), and the skull of large alligators is often preserved, thus providing evidence that can
substantiate records when no other physical evidence remains. An advantage of the method
FWC uses to measure HL is that it can be applied to a head that has the skin intact, such as
a taxidermy-mounted specimen.
FWC measures TG (circumference) with a nylon tape at the anterior margin of the
third row of scales posterior to the hind legs (Fig. 4). Tail girth can provide perspective
on an alligator’s physical condition and, combined with TL, can be used to estimate
the weight of an alligator (Woodward et al. 1992). Weight is recorded with a calibrated
scale, with the level of precision noted. Sex of alligators is determined by inserting a
finger into the cloaca to determine the presence or absence of a penis (Chabreck 1963,
Viosca 1939).
On 1 November 2010, we measured and confirmed the longest alligator that has been
measured and verified under the established protocol in Florida (Fig. 5). The alligator had
a complete tail (i.e., not shortened due to injury), and its TL was 435.5 cm (14 ft 3.5 in).
The alligator was harvested by a hunter during the statewide harvest on Lake Washington, a
naturally wide section of the St. Johns River in Brevard County. Although this is the state’s
longest alligator on record, it weighed only 296.5 kg (654 lbs), which is considerably less
than the heaviest wild alligator officially verified in Florida (473.0 kg [1043 lbs]). It is the
lightest of the 5 longest alligators recorded in Florida (Table 1). The physical appearance
of the alligator seemed characteristic of an older animal that might have been in declining
health. Its TG was undersized (TG = 91.0 cm) relative to other alligators of similar TL, and
Figure 2. The standard snout–vent length (SVL) measurement of an American Alligator is the
straight-line distance from the tip of the snout to the posterior margin of the cloacal vent.
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many of its teeth were heavily worn or missing. Condition has been defined for crocodilians
as the relative mass of individual animals (Taylor 1979), and reduced TG typically indicates
reduced body mass, or condition, for alligators of similar size (Woodward et al. 1992).
Erickson (1996) concluded that senescence contributes, in part, to lack of replacement of
missing teeth in alligators, but that dental trauma was the major cause of poor tooth replacement.
Although not necessarily an indication of age or health, the alligator also had
a soft tissue mass, approximately 10 × 7 cm, protruding from an area near the right oral
Figure 3. The standard head length (HL) measurement of an American Alligator is the straight centerline
distance from the tip of the snout to the medial posterior margin of the cranial platform, or parietal
bone, as shown in the overhead view (A). The side view (B) shows that the measurement should be
taken parallel to the surface of the skull.
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commissure. This soft tissue mass appeared to be displaced tissue from an old injury (Dan
Wolf and Mark Cunningham, FWC, Gainesville, FL, pers. comm.).
This was only the third alligator in Florida officially verified to equal or exceed 426.5
cm TL (14 ft; Table 1). The first was harvested on 5 June 1989 by a nuisance-alligator trapper
on the Apalachicola River in Franklin County in the Florida panhandle. The measured
TL for that animal was 426.5 cm (14 ft 0.0 in). On 30 September 1997, another nuisancealligator
trapper harvested an alligator measuring 428.0 cm (14 ft 0.5 in) from Lake Monroe
on the St. Johns River in central Florida. That specimen stood as the state’s longest alligator
until the current record animal was harvested from Lake Washington in 2010.
Although there have been claims of larger alligators in Florida since FWC began keeping
official records, none have been confirmed. The possibility that a larger alligator was
harvested and not officially verified seems unlikely, given the time between records, the
tendency of hunters to want to claim credit for large specimens, and the potential market
value of a record alligator. Additionally, the likelihood of a larger alligator diminishes as
male alligators reach their upper limit of asymptotic size of approximately 400–420 cm
(Chabreck and Joanen 1979, Rootes et al. 1991, Wilkinson and Rhodes 1997).
With over 20,000 alligators harvested from the wild each year (Florida Fish and Wildlife
Conservation Commission 2011), it is clear that alligators in Florida rarely reach lengths
≥400 cm (13 ft 1.5 in). This, in part, may be a result of harvests removing larger alligators
before they are able to attain their maximum length. We contacted other state wildlife agencies
in the southeastern US that have alligator populations, and requested information about
the largest alligators they had on record. Although we were unable to ascertain when all
of the states began keeping official records, most appear to coincide with the initiation of
the states’ alligator-hunting programs. Alabama, Mississippi, and Texas are the only states
other than Florida to have verified TL measurements ≥400 cm. The record for Mississippi
Figure 4. The standard tail girth (TG) measurement of an American Alligator is the circumference of
the tail at the anterior margin of the third transverse row of scales posterior to the hind legs.
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Figure 5. Florida’s record-length American Alligator that was taken by Robert Ammerman (shown in
picture) on 1 November 2010. The alligator’s total length was 435.5 cm (14 ft 3.5 in), measured as the
straight-line distance from the tip of the snout to the tip of the tail by FWC biologists.
Table 1. Body measurements of the five longest male American Alligators in Florida that have been
verified by FWC biologists. All length measurements (TL = total length, SVL = snout–vent length,
TG = tail girth, and HL = head length) are reported to the nearest 0.5 cm. All alligators in this table
had complete tails with no missing length. Weight (WT) is given in kg.
Date Harvest location TL SVL TG HL WT
1-Nov-2010 Lake Washington, Brevard Co. 435.5 229.0 91.0 59.5 296.5
30-Sep-1997 Lake Monroe, Seminole Co. 428.5 223.5 106.5 57.0 363.0
5-Jun-1989 Apalachicola River, Franklin Co. 427.0 - - 60.0 324.0
19-Sep-2001 Kovacs Bros. Ranch, Polk Co. 425.0 216.5 118.0 57.0 399.0
17-Apr-1989 Orange Lake, Alachua Co. 423.0 218.5 132.0 58.5 473.0
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was a 413.0-cm (13 ft 6.5 in) alligator taken in 2008 (Ricky Flynt, Mississippi Department
of Wildlife, Fisheries, and Parks, Jackson, MS, pers. comm.). Texas reported four alligators
≥400 cm (Amos Cooper, Texas Parks and Wildlife Department, Port Arthur, TX, pers.
comm.). The longest Texas alligator had a TL of 434.5 cm (14 ft 3.0 in) and was harvested
in 2013. Alabama verified 11 alligators ≥400 cm, including 3 that were >426.5 cm (14 ft)
(Ray Metzler, Alabama Division of Wildlife and Freshwater Fisheries, Montogomery, AL,
pers. comm.). Alabama’s official record for TL was 432.0 cm (14 ft 2.0 in) taken from two
alligators. One was harvested in 2011 and the other in 2012. The third Alabama alligator
to exceed 426.5 cm measured 429.0 cm (14 ft 1.0 in) and was also harvested in 2012.
The records for Arkansas and North Carolina were 404.0 cm (13 ft 3.0 in) and 382.0 cm
(12 ft 6.0 in), respectively (Kelly Irwin, Arkansas Game and Fish Commission, Benton,
AR; Jeff Beane, North Carolina State Museum of Natural Sciences, Raleigh, NC, pers.
comm.). Texas, Arkansas, and North Carolina indicated that their TL records are straightline
measurements similar to FWC’s protocol. Alabama and Mississippi indicated that their
TL records are based on over-the-back measurements. South Carolina does not officially
measure alligators harvested during its public hunts, but has kept length records obtained
from research activities. The longest confirmed alligator in South Carolina was 399.0 cm
(13 ft 1.0 in; Jay Butfiloski, South Carolina Department of Natural Resources, Columbia,
SC, pers. comm.). Oklahoma, Georgia and Louisiana do not keep official records of large
alligators (Richard Beagles, Oklahoma Department of Wildlife Conservation, Idabel, OK;
Greg Waters, Georgia Department of Natural Resources, Fitzgerald, GA; Ruth Elsey and
Noel Kinler, Louisiana Department of Wildlife and Fisheries, Grand Chenier and New Iberia,
LA, pers. comm.).
The fascination with large crocodilians is a likely factor contributing to exaggerated
claims of unusually large specimens. In many cases, these claims cannot be substantiated
due to the lack of physical evidence. McIlhenny’s (1935) claim of a 584-cm (19 ft 2 in) alligator
is one of those cases. Despite the questionable nature of this record, it continues to be
presented as fact in literature, such as Conant and Collins’ (1998) popular field guide. Those
managing and researching crocodilians should be cautious about accepting unusual records
with insufficient physical evidence and documentation of how data were collected. When
available, physical evidence such as a skull should be critically assessed in light of proven
allometric relationships to determine the likelihood of the claim (Greer 1974, Whitaker and
Whitaker 2008, Woodward et al. 1995).
Standardized measuring protocols are an important tool for validating and comparing
measurements of large alligators. We have found that our protocol ensures that the most
important data are collected and reported in a standardized fashion that allows for direct
comparisons among alligators. Collection of morphometric data from the largest specimens
provides additional information on allometric relationships that are often poorly understood
due to the rarity of such large animals.
It is also important to communicate to constituents the standards and means for officially
recognizing record alligators. Without this information, some specimens might go
unreported because the hunter does not care or is not aware of the process for obtaining
official recognition. The current record-length alligator, as well as previous Florida records,
were officially recognized because the hunters contacted FWC in a timely manner prior to
processing the animal. Efforts by the FWC to validate the measurements of record-sized
alligators have produced credible data and minimized the conjecture that often occurs in the
absence of data validation. We recommend that all states in the range of the American Alligator
establish consistent standards for recognizing and recording record-size specimens
2013 Southeastern Naturalist Notes Vol. 12, No. 4
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A.M. Brunell, J.P. Delaney, R.G. Spratt, D.A. Carbonneau, and J.E. Waller
across the species’ range. These standards can increase the credibility of reports of unusually
large specimens and improve the quality of data, leading to a better understanding of the
life history of the species. Furthermore, accurate and credible records can promote a more
knowledgeable public and help maintain the reputation of agencies as reliable sources for
science-based information.
Acknowledgments. The authors thank Allan Woodward (FWC) for his insight and guidance.
We are grateful to Ginny Canady (Medical University of South Carolina) for providing
the measurement illustrations and to Louis Guillette (Medical University of South Carolina)
for his efforts to assist with this manuscript. Allan Woodward and Tim O’Meara (FWC)
reviewed and provided comments on the manuscript.
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