Iguana b&w text


IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 231BOOK REVIEW

Biology of Gila Monsters and Beaded Lizards. 2005. By Daniel D.
Beck; photographs by Thomas Wiewandt. University of
California Press, USA, 211 pages. Hardback - ISBN: 0-520-
24357-9 - $49.95.

Upon learning that the IRCF was partnering with Project
Heloderma for the preservation of Guatemalan Beaded

Lizards, I realized that I needed a quick and thorough education
in all things helodermatid. I knew little about Gila Monsters and
Beaded Lizards beyond the fact that they were fascinating in
appearance and just a little bit scary. Daniel Beck’s Biology of Gila
Monsters and Beaded Lizards proved to be authoritative, well-
organized, and as comprehensive as possible given the current
state of research on the world’s only venomous lizards.

The book’s 10 chapters begin with history and evolution,
progress through the venom system and various aspects of ecol-
ogy, and end with conservation and a look to the future. The first
chapter, “Monsters in our Midst: History, Humans and
Heloderma,” places Gila Monsters and Beaded Lizards into a
sociological context. Beck chronicles the history of investigations
and presents some of the more colorful folklore and mythology.
Despite their fame (or infamy), Heloderma has been one of the
least-studied lizard genera — until recently.

Chapter 2, “Evolution, Distribution and Systematics,”
traces the complex evolutionary history of the Monstersauria,
the ancient group into which taxonomists place Heloderma and
six extinct genera. Based on skull morphology, the six currently
recognized species in the genus have changed very little over 23
million years, and qualify as living fossils. Their closest living rel-
atives include varanids (Monitor Lizards) and snakes.

If humans require any rationale to preserve Gila Monsters
and Beaded Lizards beyond the need to maintain biodiversity,
the stimulus lies in chapter 3, “The Venom System and
Envenomation.” While scientists continue to investigate
whether Heloderma venom is used to acquire prey or for defense,
Beck describes some of the many components of the venom,
their physiological effects, and potential uses in treating human
ailments as varied as diabetes, cancer, and Alzheimer’s disease.

Chapters 4 through 7 discuss aspects of ecology, including
physiology, habitat use, and population and foraging ecology.
The chapter on population ecology is co-authored with Brent
E. Martin and Charles H. Lowe. Virtually every aspect of their
ecology served to heighten my fascination with Heloderma, from
their astonishing energy efficiency to their complex refuge-
dependent activity patterns and greater than 20-year-long life
histories. Even their diet is unique; these lizards prey largely on
nests and nestlings of mammals, birds, and even other reptiles,
a feeding niche exploited by few squamates.

Chapter 8 on “Reproduction, Behavior and Heloderma in
Captivity” emphasizes the challenges involved with conducting
research on these animals. The difficulties of enticing Heloderma
to reproduce in captivity lead into chapter 9 on “Conservation.”
Gila Monsters and Beaded Lizards are faced with habitat frag-

mentation and degradation, invasive plants and fire, illegal col-
lection for the pet trade, and destruction by road traffic, domes-
tic pets, and wanton killing due to fear and ignorance. The
Guatemalan Beaded Lizard, the conservation of which the IRCF
champions, is faced with precisely these threats, and habitat pro-
tection may provide its best opportunity to avoid extinction.

In his final chapter, “Future Directions,” Beck outlines some
of the gaps in our current knowledge and suggests avenues for
future research that involve technological advances in radioteleme-
try, molecular biology, and pharmacological investigation.

On the whole, The Biology of Gila Monsters and Beaded
Lizards satisfied my appetite for information about Heloderma.
Information might have been organized by species, which would
have facilitated the acquisition of insights into each taxon. This
deficit, however, is not entirely the author’s fault; instead, the
dearth of information about some taxa, including the
Guatemalan Beaded Lizard, leaves little to reveal. Beck’s book
will surely serve the animals well as it outlines current knowl-
edge, suggests future research, and promotes an appreciation of
a remarkable group of reptiles.

AJ Gutman
IRCF

Gila Monsters and Beaded Lizards

B O O K  R E V I E W

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