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: 67
Evaluation of harmonic direction-finding systems for detecting locomotor activity Evaluation of harmonic direction-finding systems for detecting locomotor activity
We conducted a physical simulation experiment to test the efficacy of harmonic direction finding for remotely detecting locomotor activity in animals. The ability to remotely detect movement helps to avoid disturbing natural movement behavior. Remote detection implies that the observer can sense only a change in signal bearing. In our simulated movements, small changes in bearing (
Authors
V.L. Boyarski, G.H. Rodda, J. Savidge
Multiple pathways for invasion of anurans on a Pacific island Multiple pathways for invasion of anurans on a Pacific island
Since 1937, thirteen species of non-indigenous anurans have made their way to Guam. Of these, at least six have established breeding populations. Various pathways led to the introduction of these species to the island. The only anuran intentionally introduced was Chaunus marinus (formerly Bufo marinus), which was brought to Guam as a biocontrol agent. Kaloula picta, K. pulchra...
Authors
M.T. Christy, J. Savidge, G.H. Rodda
Recent records of alien anurans on the Pacific Island of Guam Recent records of alien anurans on the Pacific Island of Guam
Eight anuran species were recorded for the first time in Guam in the period May 2003-December 2005, all apparently the result of arrivals to the island since 2000. Three of the eight species (Rana guentheri, Polypedates megacephalus, and Eleutherodactylus planirostris) had well-established breeding populations by 2005. A further three (Fejevarya cf. livinocharis, Fejervarya cancrivora...
Authors
M.T. Christy, C.S. Clark, D.E. Gee, D. Vice, D.S. Vice, M.P. Warner, C.L. Tyrrell, G.H. Rodda, J. Savidge
Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range
Since their introduction to Guam shortly after World War II, brown tree snakes, Boiga irregularis (Merrem), have seriously impacted the biota and human population of the island. Understanding the biology of this exotic species will likely be important to the success of control programs. We compared the reproductive biology of 782 B. irregularis caught on Guam during the 1980s with...
Authors
J. Savidge, F.J. Qualls, G.H. Rodda
Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes
The effectiveness of methyl bromide as a fumigant for brown treesnake (Boiga irregularis) management was evaluated on Guam. Eighteen snakes in secured cloth bags were randomly positioned in a 47.7-m3 tarpaulin-covered cargo container for each fumigation treatment. Methyl bromide treatments tested were: 24 g m−3 and and 12 g m−3, both for 2-h and 1-h exposures. All treatments, except for...
Authors
P.J. Savarie, W.S. Wood, G.H. Rodda, R. Bruggers, R.M. Engeman
Glueboards for estimating lizard abundance Glueboards for estimating lizard abundance
No abstract available.
Authors
G.H. Rodda, K. Dean-Bradley, T. Fritts
The predictive power of visual searching The predictive power of visual searching
No abstract available.
Authors
G.H. Rodda, E.W. Campbell, T. Fritts, C.S. Clark
Distance sampling of forest snakes and lizards Distance sampling of forest snakes and lizards
[No abstract available]
Authors
G.H. Rodda, E.W. Campbell
Excess density compensation of island herpetofaunal assemblages Excess density compensation of island herpetofaunal assemblages
Aim Some species reach extraordinary densities on islands. Island assemblages have fewer species, however, and it is possible that island species differ from their mainland counterparts in average mass. Island assemblages could be partitioned differently (fewer species or smaller individuals) from mainland sites without differing in aggregate biomass (density compensation). Our objective...
Authors
G.H. Rodda, K. Dean-Bradley
A high validity census technique for herpetofaunal assemblages A high validity census technique for herpetofaunal assemblages
No abstract available.
Authors
G.H. Rodda, E.W. Campbell, T. Fritts
New lizard records for the Mariana Islands New lizard records for the Mariana Islands
No abstract available.
Authors
S.R. Vogt, E.W. Campbell, R. Reed, G.H. Rodda
The densest terrestrial vertebrate The densest terrestrial vertebrate
An understanding of the abundance of organisms is central to understanding ecology, but many population density estimates are unrepresentative because they were obtained from study areas chosen for the high abundance of the target species. For example, from a pool of 1072 lizard density estimates that we compiled from the literature, we sampled 303 estimates and scored each for its...
Authors
G.H. Rodda, G. Perry, R.J. Rondeau, J. Lazell
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: 67
Evaluation of harmonic direction-finding systems for detecting locomotor activity Evaluation of harmonic direction-finding systems for detecting locomotor activity
We conducted a physical simulation experiment to test the efficacy of harmonic direction finding for remotely detecting locomotor activity in animals. The ability to remotely detect movement helps to avoid disturbing natural movement behavior. Remote detection implies that the observer can sense only a change in signal bearing. In our simulated movements, small changes in bearing (
Authors
V.L. Boyarski, G.H. Rodda, J. Savidge
Multiple pathways for invasion of anurans on a Pacific island Multiple pathways for invasion of anurans on a Pacific island
Since 1937, thirteen species of non-indigenous anurans have made their way to Guam. Of these, at least six have established breeding populations. Various pathways led to the introduction of these species to the island. The only anuran intentionally introduced was Chaunus marinus (formerly Bufo marinus), which was brought to Guam as a biocontrol agent. Kaloula picta, K. pulchra...
Authors
M.T. Christy, J. Savidge, G.H. Rodda
Recent records of alien anurans on the Pacific Island of Guam Recent records of alien anurans on the Pacific Island of Guam
Eight anuran species were recorded for the first time in Guam in the period May 2003-December 2005, all apparently the result of arrivals to the island since 2000. Three of the eight species (Rana guentheri, Polypedates megacephalus, and Eleutherodactylus planirostris) had well-established breeding populations by 2005. A further three (Fejevarya cf. livinocharis, Fejervarya cancrivora...
Authors
M.T. Christy, C.S. Clark, D.E. Gee, D. Vice, D.S. Vice, M.P. Warner, C.L. Tyrrell, G.H. Rodda, J. Savidge
Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range Reproductive biology of the brown tree snake, Boiga irregularis (Reptilia: Colubridae), during colonization of Guam and comparison with that in their native range
Since their introduction to Guam shortly after World War II, brown tree snakes, Boiga irregularis (Merrem), have seriously impacted the biota and human population of the island. Understanding the biology of this exotic species will likely be important to the success of control programs. We compared the reproductive biology of 782 B. irregularis caught on Guam during the 1980s with...
Authors
J. Savidge, F.J. Qualls, G.H. Rodda
Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes Effectiveness of methyl bromide as a cargo fumigant for brown treesnakes
The effectiveness of methyl bromide as a fumigant for brown treesnake (Boiga irregularis) management was evaluated on Guam. Eighteen snakes in secured cloth bags were randomly positioned in a 47.7-m3 tarpaulin-covered cargo container for each fumigation treatment. Methyl bromide treatments tested were: 24 g m−3 and and 12 g m−3, both for 2-h and 1-h exposures. All treatments, except for...
Authors
P.J. Savarie, W.S. Wood, G.H. Rodda, R. Bruggers, R.M. Engeman
Glueboards for estimating lizard abundance Glueboards for estimating lizard abundance
No abstract available.
Authors
G.H. Rodda, K. Dean-Bradley, T. Fritts
The predictive power of visual searching The predictive power of visual searching
No abstract available.
Authors
G.H. Rodda, E.W. Campbell, T. Fritts, C.S. Clark
Distance sampling of forest snakes and lizards Distance sampling of forest snakes and lizards
[No abstract available]
Authors
G.H. Rodda, E.W. Campbell
Excess density compensation of island herpetofaunal assemblages Excess density compensation of island herpetofaunal assemblages
Aim Some species reach extraordinary densities on islands. Island assemblages have fewer species, however, and it is possible that island species differ from their mainland counterparts in average mass. Island assemblages could be partitioned differently (fewer species or smaller individuals) from mainland sites without differing in aggregate biomass (density compensation). Our objective...
Authors
G.H. Rodda, K. Dean-Bradley
A high validity census technique for herpetofaunal assemblages A high validity census technique for herpetofaunal assemblages
No abstract available.
Authors
G.H. Rodda, E.W. Campbell, T. Fritts
New lizard records for the Mariana Islands New lizard records for the Mariana Islands
No abstract available.
Authors
S.R. Vogt, E.W. Campbell, R. Reed, G.H. Rodda
The densest terrestrial vertebrate The densest terrestrial vertebrate
An understanding of the abundance of organisms is central to understanding ecology, but many population density estimates are unrepresentative because they were obtained from study areas chosen for the high abundance of the target species. For example, from a pool of 1072 lizard density estimates that we compiled from the literature, we sampled 303 estimates and scored each for its...
Authors
G.H. Rodda, G. Perry, R.J. Rondeau, J. Lazell
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.