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In August 1979, scientists who were studying the systematics,
behavior, ecology, physiology, and conservation of iguanas

met to compare notes and take part in a symposium held at the
University of Tennessee, Knoxville. The symposium was orga-
nized by Gordon M. Burghardt of the University of Tennessee
and A. Stanley Rand of the Smithsonian Tropical Research
Institute (STRI) in Panama. It led to The Iguanas of the World:
Their Behavior, Ecology and Conservation (1982. Noyes
Publications, Park Ridge, New Jersey). Edited by Burghardt and
Rand, the volume quickly became something of a bible for those
of us interested in the biology of iguanas. In 1997, a similar sym-
posium, held at the University of Washington in Seattle, resulted
in the second in what will hopefully become a continuing series
devoted to these fascinating lizards (Alberts et al., eds. 2004.
IGUANAS: Biology and Conservation. Univ. California Press,
Berkeley; see review on p. 60). Forty-two biologists contributed
to the latest volume and it was dedicated to Gordon Burghardt
and Stan Rand. Gordon was the only individual to contribute
to both the 1982 and 2004 volumes.

Gordon was born in Milwaukee, Wisconsin and remem-
bers being drawn to reptiles at the age of about eight. Although
he initially majored in Chemistry as an undergraduate at the
University of Chicago, he soon became aware of the program in
biopsychology and changed majors. His adviser was Eckhard H.
Hess. Hess knew that the behavior of reptiles had received little
attention from ethologists (scientists who study the natural
behavior of animals) and encouraged Gordon, while still an
undergraduate, to become involved in research. A problem,
however, arose. Gordon’s primary interest was in snakes, and
Hess’s wife hated snakes. She had extracted a promise from her
husband that none would be allowed in his laboratory. As a
result, the man who would later conduct research on giant
iguanas began small, by studying the feeding behavior of Green
Anoles (Anolis carolinensis) and Five-lined Skinks (Eumeces fas-
ciatus). This work led, in 1964, to the first of over 150 research
papers, books, and book chapters that Gordon has published to
date. Despite the subjects of that first study, Gordon was still
determined to study snakes and the opportunity arose when he
was given a pregnant garter snake. Unable to keep it in Hess’s
lab, he set it up in his studio apartment and, before long, he had
an entire litter of snakes, each housed in its own small cage and
all squeezed into his small apartment — and that was where he
began the research on the feeding behavior of snakes that has

been a hallmark of his career. This research became the basis for
his doctoral research and, fortunately, by the time he entered
graduate school, Hess had found a way for him to house snakes
in his laboratory.

After receiving his Ph.D. in Biopsychology, Gordon taught
biology at the University of Chicago for about a year and a half
before joining the faculty of the Department of Psychology at
the University of Tennessee, Knoxville. He presently holds a

52 IGUANA  •  VOLUME 11, NUMBER 1  •  MARCH 2004 ECHTERNACHT

P R O F I L E

Gordon Burghardt:
Forty Years of Studying Reptilian Behavior

Arthur C. Echternacht

University of Tennessee

A recent photograph of Gordon Burghardt (and friend) in his office at
the University of Tennessee. Photograph courtesy of the University of
Tennessee Photography Services.

�



IGUANA  •  VOLUME 11, NUMBER 1  •  MARCH 2004 53GORDON BURGHARDT

joint appointment in that department and in the Department
of Ecology & Evolutionary Biology (EEB). Until it was merged
into EEB, he directed the Graduate Program in Ethology, which
he had founded. He directs the research of undergraduate and
graduate students in both Psychology and Biology and teaches,
among other courses, the popular Comparative Animal
Behavior Laboratory course (the “CAB lab”). Very active in sev-
eral professional societies, he is Past-President of the Animal
Behavior Society, a member of the Editorial/Advisory Board of
the International Iguana Society, the IUCN Species Survival
Commission Iguana Specialist Group, and the AZA Komodo
Dragon Species Survival Plan management group grant panel.
Virtually all of his research has involved living animals, and he
is a very active advocate for the ethical treatment of all animals
used in research.

He has been a strong proponent of collaboration between
university-based biologists and their zoo-based counterparts, and
several of his graduate students have conducted research in zoos.
He served for many years on an advisory board for the Knoxville
Zoological Park and once provided a foster home for a young lion
in his basement, which became an effective security device when
the need arose. Having broken the glass in a basement door, the
would-be burglar apparently encountered the lion, which was no
longer a small cub and had the run of the house. One has to guess
what happened but, whatever ensued, the burglar left in an appar-
ent rush. Not only was nothing stolen, not even the camera equip-
ment in plain view, but the hammer used to gain entry was left
behind on the floor. Gordon also fostered two orphaned bear
cubs, which led to a long involvement with studies of Black Bear
behavior, including bear-human interactions.

In 1973, Gordon attended a meeting of herpetologists in
Costa Rica and, afterward, visited the STRI facility on Barro
Colorado Island (BCI) in Panama. Although he was there to
study snakes, his attention was drawn to the large numbers of
baby Green Iguanas (Iguana iguana) that were basking and feed-

ing in the shrubs around his cabin. At the time, Stan Rand was
studying the nesting behavior of adult iguanas, but no one was
studying the hatchlings. Gordon soon returned to BCI and ini-
tiated what was to be a long series of studies on the nesting
behavior of female iguanas, the emergence and dispersal of
hatchlings, and various aspects of adult behavior. He was joined
in these studies by an army of undergraduate, graduate, and
postdoctoral students from the United States and Latin America.

Many of these studies were carried out on Slothia, a small
(0.3 ha) islet in Gatun Lake near BCI. Aside from its proximity
to the STRI facility on BCI, Slothia was ideal for these studies
because, working from a blind, the iguanas could easily be
observed. Stan Rand had found that over 100 female iguanas
migrated to Slothia yearly to nest communally in a small (8 x 6
m) clearing. In this crowded environment, each female aggres-
sively defended her nest against others who were intent on
appropriating a partially completed nest or who might, in the
process of digging their own nests, uncover and scatter her eggs.
They all shared space with American Crocodiles (Crocodylus acu-
tus). This was an uncomfortable arrangement, at least for the
iguanas and the biologists: the crocodiles occasionally ate an
iguana and Gordon has very dramatic film footage, taken in the
course of observing iguanas, of a huge crocodile quite unex-

A blind used by Gordon Burghardt and his students to study the nest-
ing behavior of Green Iguanas on Slothia, an islet adjacent to Barro
Colorado Island, Panama. Photograph by Gordon Burghardt.

Gordon Burghardt in full field mode demonstrating the proper use of
a “stump-ripper” to students prior to a safari around his cabin in the
wilds of eastern Tennessee. Photograph by Paul T. Andreadis.



pectedly launching itself out of the water and coming to rest
directly in front of the blind.

Among the results of that research, we now know that
hatchling iguanas, like hatchling Green Sea Turtles (Chelonia
mydas), emerge synchronously from the nest chamber. They
remain on Slothia for a few days before rapidly dispersing in
groups by swimming to the adjacent mainland. For up to a year
following emergence from the nest, most baby iguanas remain
in groups, and Gordon and Rand have shown that, on BCI, the
growth rates of iguanas in these groups is higher than those that
adopt a solitary existence. A partial, but substantial, list of pub-
lications on iguanas by Gordon and his collaborators can be
found in his chapter in IGUANAS: Biology and Conservation.

All the while Gordon was conducting research on iguanas,
he also was building on his earlier studies of snake behavior and
ecology. The chemical senses, especially those associated with the
vomeronasal or Jacobson’s organ (vomerolfaction), are very
important to snakes and are especially critical in, among other
things, prey identification. In his early research, Gordon estab-
lished what have become the standard methods for studying the
chemical cues that elicit predatory responses in snakes. He has
been especially interested in whether the attraction to a particu-
lar type of prey (or, more accurately, prey chemical) is inherited,
implying an evolutionary basis, modifiable by experience, and
whether preferences change ontogenetically, that is, as a snake
ages. These interests also have led him to study geographic vari-
ation in prey preferences within a single species and among
closely related species. Much of this work has involved North
American Garter Snakes (Thamnophis spp.) and Water Snakes
(Nerodia spp.), and his lab is typically full of converted plastic
shoe boxes, each housing an individual new-born snake.

Recently, he has been involved in an effort to save an
important piece of the habitat of Butler’s Garter Snake
(Thamnophis butleri), which had been threatened by land devel-
opment in Milwaukee, Wisconsin. A group of developers had
asked the state to remove the snake from the state’s official list
of endangered and threatened species. As of this writing,
Gordon’s efforts, and those of others of like mind, have won, at
least temporarily. In January, a state legislative panel directed the

Wisconsin Department of Natural Resources to formulate a
plan for protecting the species from developers.

Gordon’s snake research has occupied most of his time
lately, but he has broadened the scope of his studies to include
consideration of the enrichment and psychological well-being of
reptiles, the behavior of Monitor Lizards (Varanus spp.), and
play behavior, cognition, and visual perception in reptiles and
fish. His book on animal play will soon be published.

In a rather radical departure from his research on reptiles,
he soon will leave Tennessee temporarily to study amphibians at
the National Amphibian Conservation Center at the Detroit
Zoo. Iguanas, however, are never far from his mind, and he con-
tinues to be a valuable source of information, advice, and assis-
tance to anyone studying these lizards. One gets the impression
that it wouldn’t take much to lure him back into the fold on a
more active basis.

If you would like to learn more about Gordon’s activities,
you can visit his web site: http://web.utk.edu/~gburghar.

54 IGUANA  •  VOLUME 11, NUMBER 1  •  MARCH 2004 ECHTERNACHT

Hatchling Green Iguanas emerging synchronously from their nest
chamber on Slothia. Photograph by Gordon Burghardt.

Stan Rand (left) and Gordon Burghardt relaxing aboard a research ves-
sel on the return trip from the Archipélago de las Perlas in the Bahía de
Panamá, where they had been studying the nesting behavior of Green
Iguanas. Photograph courtesy of Gordon H. Rodda, photographer unknown.

What Goes Around 
Comes Around

When Allison Alberts, who was featured in the profile in
IGUANA 10(4), decided to change her major from English
to biology, the decision was based, at least in part, on her
experiences during the herpetology unit of a two-semester
course on the “Natural History of Vertebrates.” That unit
was taught by Harry Greene, who had been one of Gordon
Burghardt’s students at the University of Tennessee. Yet
another of Gordon’s students, Paul J. Weldon, had earned
his doctorate working on snake behavior. Later, when Paul
was on the faculty at Texas A&M University, one of his
post-doctoral students was none other than Allison Alberts.


