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
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2012-present: Natural history traits of actual and potential invasive lizards (library research)
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1987-2012: Brown Treesnakes (Guam), Giant constrictors (Florida, Puerto Rico), Wolf Snakes (Mauritius)
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1982-1987: Green Iguana social behavior (Venezuela)
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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: 60
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 proximity t
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 improving
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) on Guam. Ho
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 species. We u
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 boards) wit
Movements and activity of juvenile Brown Treesnakes (Boiga irregularis)
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 (n = 86),
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) predation
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.
Aims: Our
Data for giant constrictors - Biological management profiles and an establishment risk assessment for nine large species of pythons, anacondas, and the boa constrictor
Giant Constrictors' Climate Space
The giant constrictors' climate space data set represents the information needed to recreate the climate space and climate matching analyses in Reed and Rodda (2009). A detailed methodology and results are included in that report. The data include locations for nine species of large constrictors including Python molurus, Broghammerus reticulatus, P. sebae, P. nat
Burmese Pythons and other giant constrictors
No abstract available.
Boiga irregularis (Brown Treesnake). Predation attempt by crab
No abstract available.
Boiga irregularis (Brown Treesnake). Predation attempt by praying mantis
No abstract available.
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
- Publications
Filter Total Items: 60
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 proximity tHabitat 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 improvingExperimental 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) on Guam. HoDetection 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 species. We uGeneral 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 boards) witMovements and activity of juvenile Brown Treesnakes (Boiga irregularis)
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 (n = 86),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) predationA 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. Aims: OurData for giant constrictors - Biological management profiles and an establishment risk assessment for nine large species of pythons, anacondas, and the boa constrictor
Giant Constrictors' Climate Space The giant constrictors' climate space data set represents the information needed to recreate the climate space and climate matching analyses in Reed and Rodda (2009). A detailed methodology and results are included in that report. The data include locations for nine species of large constrictors including Python molurus, Broghammerus reticulatus, P. sebae, P. natBurmese Pythons and other giant constrictors
No abstract available.Boiga irregularis (Brown Treesnake). Predation attempt by crab
No abstract available.Boiga irregularis (Brown Treesnake). Predation attempt by praying mantis
No abstract available.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.