Gordon H Rodda
Gordon Rodda is a Scientist Emeritus at USGS Fort Collins Science Center.
His area of professional expertise is the ecology and management of invasive reptiles, beginning with Brown Treesnakes on Guam in 1987. Upon retirement in 2012 he shifted focus to preventing new invasions by screening prospective invaders using natural history traits. He is compiling the natural history traits of all lizards, which resulted in publication of Lizards of the World.
Professional Studies/Experience
- 2012-present: Natural history traits of actual and potential invasive lizards (library research)
- 1987-2012: Brown Treesnakes (Guam), Giant constrictors (Florida, Puerto Rico), Wolf Snakes (Mauritius)
- 1982-1987: Green Iguana social behavior (Venezuela)
- 1978-1981: American Alligator navigation (Florida), American Crocodile (Panama)
Education and Certifications
Ph.D. Behavioral Biology, Cornell Univ. 1982
B.A. Organismic Biology, Univ. of Colorado - Boulder, 1975
Science and Products
Filter Total Items: 66
Behavioral plasticity in detection height of an invasive, arboreal snake based on size, condition, and prey Behavioral plasticity in detection height of an invasive, arboreal snake based on size, condition, and prey
ContextAnimals may adjust their behavior in predictable ways to balance tradeoffs between resource acquisition and survival or fecundity. Microhabitat selection based on individual traits or environmental conditions is one measure of risk–reward tradeoffs by individuals.AimsWe used data from observational and manipulative studies to investigate whether an arboreal snake (brown treesnake...
Authors
Melia G. Nafus, Levi Gray, Page E. Klug, Gordon H. Rodda, Scott Michael Goetz
Can we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion Can we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion
Detection of invasive species and decisions centered around early detection and rapid response (EDRR) are notorious challenges for decision makers. Detection probability is low for cryptic species, resources are limited, and ecological harm (especially for island ecosystems) can result from failure to remove invasive species due to inadequate or delayed surveillance efforts. Due to the...
Authors
Amy A. Yackel Adams, Patrick D Barnhart, Gordon H. Rodda, Eric T. Hileman, Melia Gail Nafus, Robert Reed
Emoia atrocostata (mangrove skink) Emoia atrocostata (mangrove skink)
No abstract available.
Authors
Robert Reed, Lea' R. Bonewell, Gordon H. Rodda
Habitat type and structure affect trap capture success of an invasive snake across variable densities Habitat type and structure affect trap capture success of an invasive snake across variable densities
Detection represents an important limitation of accurately estimating population size, abundance, and habitat suitability for wildlife, which can be especially true for cryptic animals. Moreover, for reptiles, juveniles are often less likely to be detected than later life stages. In the case of invasive species, preventing false negatives early in the invasion process can be critical for...
Authors
Melia G. Nafus, Amy A. Yackel Adams, Page E. Klug, Gordon H. Rodda
Experimental landscape reduction of wild rodents increases movements in the invasive brown treesnake (Boiga irregularis) Experimental landscape reduction of wild rodents increases movements in the invasive brown treesnake (Boiga irregularis)
Experimental studies evaluating the effects of food availability on the movement of free-ranging animals generally involve food supplementation rather than suppression. Both approaches can yield similar insights, but we were interested in the potential for using food suppression for the management and control of invasive predators, in particular, the brown treesnake (Boiga irregularis)...
Authors
Michelle Christy, Julie A. Savidge, Amy A. Yackel Adams, James E. Gragg, Gordon H. Rodda
Detection rates of geckos in visual surveys: Turning confounding variables into useful knowledge Detection rates of geckos in visual surveys: Turning confounding variables into useful knowledge
Transect surveys without some means of estimating detection probabilities generate population size indices prone to bias because survey conditions differ in time and space. Knowing what causes such bias can help guide the collection of relevant survey covariates, correct the survey data, anticipate situations where bias might be unacceptably large, and elucidate the ecology of target...
Authors
Bjorn Lardner, Gordon H. Rodda, Amy A. Yackel Adams, Julie A. Savidge, Robert N. Reed
General herpetological collecting is size-biased for five Pacific lizards General herpetological collecting is size-biased for five Pacific lizards
Accurate estimation of a species' size distribution is a key component of characterizing its ecology, evolution, physiology, and demography. We compared the body size distributions of five Pacific lizards (Carlia ailanpalai, Emoia caeruleocauda, Gehyra mutilata, Hemidactylus frenatus, and Lepidodactylus lugubris) from general herpetological collecting (including visual surveys and glue...
Authors
Gordon H. Rodda, Amy A. Yackel Adams, Earl W. Campbell, Thomas H. Fritts
Stability of detectability over 17 years at a single site and other lizard detection comparisons from Guam Stability of detectability over 17 years at a single site and other lizard detection comparisons from Guam
To obtain quantitative information about population dynamics from counts of animals, the per capita detectabilities of each species must remain constant over the course of monitoring. We characterized lizard detection constancy for four species over 17 yr from a single site in northern Guam, a relatively benign situation because detection was relatively easy and we were able to hold...
Authors
Gordon H. Rodda, Kathryn Dean-Bradley, Earl W. Campbell, Thomas H. Fritts, Bjorn Lardner, Amy A. Yackel Adams, Robert N. Reed
Movements and activity of juvenile Brown Treesnakes (<i>Boiga irregularis</i>) Movements and activity of juvenile Brown Treesnakes (<i>Boiga irregularis</i>)
Understanding the spatial ecology and foraging strategy of invasive animals is essential for success in control or eradication. We studied movements and activity in juvenile Brown Treesnakes on Guam, as this population segment has proven particularly difficult to control. Distance between daytime refugia (from telemetry of 18 juveniles, 423-800 mm snout-vent length) ranged from 0-118 m...
Authors
Bjorn Lardner, Julie A. Savidge, Robert N. Reed, Gordon H. Rodda
Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii
We summarize information on current distribution of the invasive lizard Chamaeleo jacksonii and predict its potential distribution in the Hawaiian Islands. Potential distribution maps are based on climate models developed from known localities in its native range and its Hawaiian range. We also present results of analysis of stomach contents of a sample of 34 chameleons collected from...
Authors
Fred Kraus, Arthur Medeiros, David Preston, Catherine S. Jarnevich, Gordon H. Rodda
Do predators control prey species abundance? An experimental test with brown treesnakes on Guam Do predators control prey species abundance? An experimental test with brown treesnakes on Guam
The effect of predators on the abundance of prey species is a topic of ongoing debate in ecology; the effect of snake predators on their prey has been less debated, as there exists a general consensus that snakes do not negatively influence the abundance of their prey. However, this viewpoint has not been adequately tested. We quantified the effect of brown treesnake (Boiga irregularis)...
Authors
Earl W. Campbell, Amy A. Yackel Adams, Sarah J. Converse, Thomas H. Fritts, Gordon H. Rodda
A field test of attractant traps for invasive Burmese pythons (Python molurus bivittatus) in southern Florida A field test of attractant traps for invasive Burmese pythons (Python molurus bivittatus) in southern Florida
Context: Invasive Burmese pythons (Python molurus bivittatus) are established over thousands of square kilometres of southern Florida, USA, and consume a wide range of native vertebrates. Few tools are available to control the python population, and none of the available tools have been validated in the field to assess capture success as a proportion of pythons available to be captured...
Authors
Robert N. Reed, Kristen M. Hart, Gordon H. Rodda, Frank J. Mazzotti, Ray W. Snow, Michael Cherkiss, Rondald Rozar, Scott Goetz
Non-USGS Publications**
Rodda, G.H. 2003. Biology and reproduction of Iguana iguana in the wild. In: Biology, husbandry, and medicine of the green iguana. Malabar, Florida: Kreiger Publishing. 1-27.
Rodda, G.H. 1984. The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity. Journal of Comparative Physiology A. 154(5): 649-658.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
Filter Total Items: 66
Behavioral plasticity in detection height of an invasive, arboreal snake based on size, condition, and prey Behavioral plasticity in detection height of an invasive, arboreal snake based on size, condition, and prey
ContextAnimals may adjust their behavior in predictable ways to balance tradeoffs between resource acquisition and survival or fecundity. Microhabitat selection based on individual traits or environmental conditions is one measure of risk–reward tradeoffs by individuals.AimsWe used data from observational and manipulative studies to investigate whether an arboreal snake (brown treesnake...
Authors
Melia G. Nafus, Levi Gray, Page E. Klug, Gordon H. Rodda, Scott Michael Goetz
Can we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion Can we prove that an undetected species is absent? Evaluating whether brown treesnakes are established on the island of Saipan using surveillance and expert opinion
Detection of invasive species and decisions centered around early detection and rapid response (EDRR) are notorious challenges for decision makers. Detection probability is low for cryptic species, resources are limited, and ecological harm (especially for island ecosystems) can result from failure to remove invasive species due to inadequate or delayed surveillance efforts. Due to the...
Authors
Amy A. Yackel Adams, Patrick D Barnhart, Gordon H. Rodda, Eric T. Hileman, Melia Gail Nafus, Robert Reed
Emoia atrocostata (mangrove skink) Emoia atrocostata (mangrove skink)
No abstract available.
Authors
Robert Reed, Lea' R. Bonewell, Gordon H. Rodda
Habitat type and structure affect trap capture success of an invasive snake across variable densities Habitat type and structure affect trap capture success of an invasive snake across variable densities
Detection represents an important limitation of accurately estimating population size, abundance, and habitat suitability for wildlife, which can be especially true for cryptic animals. Moreover, for reptiles, juveniles are often less likely to be detected than later life stages. In the case of invasive species, preventing false negatives early in the invasion process can be critical for...
Authors
Melia G. Nafus, Amy A. Yackel Adams, Page E. Klug, Gordon H. Rodda
Experimental landscape reduction of wild rodents increases movements in the invasive brown treesnake (Boiga irregularis) Experimental landscape reduction of wild rodents increases movements in the invasive brown treesnake (Boiga irregularis)
Experimental studies evaluating the effects of food availability on the movement of free-ranging animals generally involve food supplementation rather than suppression. Both approaches can yield similar insights, but we were interested in the potential for using food suppression for the management and control of invasive predators, in particular, the brown treesnake (Boiga irregularis)...
Authors
Michelle Christy, Julie A. Savidge, Amy A. Yackel Adams, James E. Gragg, Gordon H. Rodda
Detection rates of geckos in visual surveys: Turning confounding variables into useful knowledge Detection rates of geckos in visual surveys: Turning confounding variables into useful knowledge
Transect surveys without some means of estimating detection probabilities generate population size indices prone to bias because survey conditions differ in time and space. Knowing what causes such bias can help guide the collection of relevant survey covariates, correct the survey data, anticipate situations where bias might be unacceptably large, and elucidate the ecology of target...
Authors
Bjorn Lardner, Gordon H. Rodda, Amy A. Yackel Adams, Julie A. Savidge, Robert N. Reed
General herpetological collecting is size-biased for five Pacific lizards General herpetological collecting is size-biased for five Pacific lizards
Accurate estimation of a species' size distribution is a key component of characterizing its ecology, evolution, physiology, and demography. We compared the body size distributions of five Pacific lizards (Carlia ailanpalai, Emoia caeruleocauda, Gehyra mutilata, Hemidactylus frenatus, and Lepidodactylus lugubris) from general herpetological collecting (including visual surveys and glue...
Authors
Gordon H. Rodda, Amy A. Yackel Adams, Earl W. Campbell, Thomas H. Fritts
Stability of detectability over 17 years at a single site and other lizard detection comparisons from Guam Stability of detectability over 17 years at a single site and other lizard detection comparisons from Guam
To obtain quantitative information about population dynamics from counts of animals, the per capita detectabilities of each species must remain constant over the course of monitoring. We characterized lizard detection constancy for four species over 17 yr from a single site in northern Guam, a relatively benign situation because detection was relatively easy and we were able to hold...
Authors
Gordon H. Rodda, Kathryn Dean-Bradley, Earl W. Campbell, Thomas H. Fritts, Bjorn Lardner, Amy A. Yackel Adams, Robert N. Reed
Movements and activity of juvenile Brown Treesnakes (<i>Boiga irregularis</i>) Movements and activity of juvenile Brown Treesnakes (<i>Boiga irregularis</i>)
Understanding the spatial ecology and foraging strategy of invasive animals is essential for success in control or eradication. We studied movements and activity in juvenile Brown Treesnakes on Guam, as this population segment has proven particularly difficult to control. Distance between daytime refugia (from telemetry of 18 juveniles, 423-800 mm snout-vent length) ranged from 0-118 m...
Authors
Bjorn Lardner, Julie A. Savidge, Robert N. Reed, Gordon H. Rodda
Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii
We summarize information on current distribution of the invasive lizard Chamaeleo jacksonii and predict its potential distribution in the Hawaiian Islands. Potential distribution maps are based on climate models developed from known localities in its native range and its Hawaiian range. We also present results of analysis of stomach contents of a sample of 34 chameleons collected from...
Authors
Fred Kraus, Arthur Medeiros, David Preston, Catherine S. Jarnevich, Gordon H. Rodda
Do predators control prey species abundance? An experimental test with brown treesnakes on Guam Do predators control prey species abundance? An experimental test with brown treesnakes on Guam
The effect of predators on the abundance of prey species is a topic of ongoing debate in ecology; the effect of snake predators on their prey has been less debated, as there exists a general consensus that snakes do not negatively influence the abundance of their prey. However, this viewpoint has not been adequately tested. We quantified the effect of brown treesnake (Boiga irregularis)...
Authors
Earl W. Campbell, Amy A. Yackel Adams, Sarah J. Converse, Thomas H. Fritts, Gordon H. Rodda
A field test of attractant traps for invasive Burmese pythons (Python molurus bivittatus) in southern Florida A field test of attractant traps for invasive Burmese pythons (Python molurus bivittatus) in southern Florida
Context: Invasive Burmese pythons (Python molurus bivittatus) are established over thousands of square kilometres of southern Florida, USA, and consume a wide range of native vertebrates. Few tools are available to control the python population, and none of the available tools have been validated in the field to assess capture success as a proportion of pythons available to be captured...
Authors
Robert N. Reed, Kristen M. Hart, Gordon H. Rodda, Frank J. Mazzotti, Ray W. Snow, Michael Cherkiss, Rondald Rozar, Scott Goetz
Non-USGS Publications**
Rodda, G.H. 2003. Biology and reproduction of Iguana iguana in the wild. In: Biology, husbandry, and medicine of the green iguana. Malabar, Florida: Kreiger Publishing. 1-27.
Rodda, G.H. 1984. The orientation and navigation of juvenile alligators: evidence of magnetic sensitivity. Journal of Comparative Physiology A. 154(5): 649-658.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.