Gordon Rodda - Academia.edu (original) (raw)
Papers by Gordon Rodda
Problem Snake Management, 2020
On the Pacific island of Guam, control of the invasive Brown Treesnake (Boiga irregularis) relies... more On the Pacific island of Guam, control of the invasive Brown Treesnake (Boiga irregularis) relies largely on methods that use mice as bait. Juvenile B. irregularis feed primarily on lizards and their eggs, but little is known about their prey preference. We conducted an experiment to investigate preferences for, and acceptance of, dead geckos, skinks, and neonatal mice, in juvenile B. irregularis ranging from 290 mm to ca. 700 mm snout-vent length (SVL). Snakes of all sizes showed a preference for geckos over skinks and neonatal mice. Geckos were the first prey chosen in 87% of 224 initial trials (56 snakes subjected to four trials each; 33% would be expected from a random choice). The smallest snakes had the most pronounced preference. Although many of the snakes accepted neonatal mice and/or skinks, some snakes of all sizes were reluctant to feed on anything but geckos, especially when well fed. We also addressed the hypothesis that repeated encounters with a particular prey type ...
Problem Snake Management, 2020
Page 1. 20 A StDte-of-the-Art Trap for . the Brown Treesnake t • GORDON H. RODDA THOMAS H. FRITTS... more Page 1. 20 A StDte-of-the-Art Trap for . the Brown Treesnake t • GORDON H. RODDA THOMAS H. FRITTS CRAIG S. CLARK STEVE W. GOT TE DAVID CHISZAR Traps can be used to reduce the density of snakes in high-priority ...
Herpetological review, 2011
The brown tree snake (Boiga irregularis), accidentally introduced on Guam shortly after World War... more The brown tree snake (Boiga irregularis), accidentally introduced on Guam shortly after World War 11, is the target of extensive efforts aimed at reducing populations and preventing their spread to other Pacific islands. Chemical attractants and repellents have been investigated, and this paper presents an overview of current knowledge. In particular, chemical cues that have strong effects in laboratory tests have had only modest (though significant) effects in field tests on Guam. Reasons for the different outcomes of laboratory and field studies are discussed along with recommendations for the redesign of laboratory experiments.
Encyclopedia of Biological Invasions, 2019
Management of Biological Invasions, 2021
Management of Biological Invasions, 2017
Proceedings of the Vertebrate Pest Conference, 1998
Journal of Animal Ecology, 2017
Journal of Herpetology, 2015
Abstract To obtain quantitative information about population dynamics from counts of animals, the... more Abstract 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 constant the site, habitat type, species, season, and sampling method. We monitored two species of diurnal terrestrial skinks (Carlia ailanpalai [Curious Skink], Emoia caeruleocauda [Pacific Bluetailed Skink]) using glueboards placed on the ground in the shade for 3 h on rainless mornings, yielding 10,286 skink captures. We additionally monitored two species of nocturnal arboreal geckos (Hemidactylus frenatus [Common House Gecko]; Lepidodactylus lugubris [Mourning Gecko]) on the basis of 15,212 sightings. We compared these count samples to a series of complete censuses we conducted from four or more total removal plots (everything removed to mineral soil) totaling 400 m2 (about 1% of study site) in each of the years 1995, 1999, and 2012, providing time-stamped quantification of detectability for each species. Unfortunately, the actual population trajectories taken by the four species were masked by unexplained variation in detectability. This observation of debilitating latent variability in lizard detectability under nearly ideal conditions undercuts our trust in population estimation techniques that fail to quantify venue-specific detectability, rely on pooled detection probability estimates, or assume that modulation in predefined environmental covariates suffices for estimating detectability.
Problem Snake Management, 2020
On the Pacific island of Guam, control of the invasive Brown Treesnake (Boiga irregularis) relies... more On the Pacific island of Guam, control of the invasive Brown Treesnake (Boiga irregularis) relies largely on methods that use mice as bait. Juvenile B. irregularis feed primarily on lizards and their eggs, but little is known about their prey preference. We conducted an experiment to investigate preferences for, and acceptance of, dead geckos, skinks, and neonatal mice, in juvenile B. irregularis ranging from 290 mm to ca. 700 mm snout-vent length (SVL). Snakes of all sizes showed a preference for geckos over skinks and neonatal mice. Geckos were the first prey chosen in 87% of 224 initial trials (56 snakes subjected to four trials each; 33% would be expected from a random choice). The smallest snakes had the most pronounced preference. Although many of the snakes accepted neonatal mice and/or skinks, some snakes of all sizes were reluctant to feed on anything but geckos, especially when well fed. We also addressed the hypothesis that repeated encounters with a particular prey type ...
Problem Snake Management, 2020
Page 1. 20 A StDte-of-the-Art Trap for . the Brown Treesnake t • GORDON H. RODDA THOMAS H. FRITTS... more Page 1. 20 A StDte-of-the-Art Trap for . the Brown Treesnake t • GORDON H. RODDA THOMAS H. FRITTS CRAIG S. CLARK STEVE W. GOT TE DAVID CHISZAR Traps can be used to reduce the density of snakes in high-priority ...
Herpetological review, 2011
The brown tree snake (Boiga irregularis), accidentally introduced on Guam shortly after World War... more The brown tree snake (Boiga irregularis), accidentally introduced on Guam shortly after World War 11, is the target of extensive efforts aimed at reducing populations and preventing their spread to other Pacific islands. Chemical attractants and repellents have been investigated, and this paper presents an overview of current knowledge. In particular, chemical cues that have strong effects in laboratory tests have had only modest (though significant) effects in field tests on Guam. Reasons for the different outcomes of laboratory and field studies are discussed along with recommendations for the redesign of laboratory experiments.
Encyclopedia of Biological Invasions, 2019
Management of Biological Invasions, 2021
Management of Biological Invasions, 2017
Proceedings of the Vertebrate Pest Conference, 1998
Journal of Animal Ecology, 2017
Journal of Herpetology, 2015
Abstract To obtain quantitative information about population dynamics from counts of animals, the... more Abstract 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 constant the site, habitat type, species, season, and sampling method. We monitored two species of diurnal terrestrial skinks (Carlia ailanpalai [Curious Skink], Emoia caeruleocauda [Pacific Bluetailed Skink]) using glueboards placed on the ground in the shade for 3 h on rainless mornings, yielding 10,286 skink captures. We additionally monitored two species of nocturnal arboreal geckos (Hemidactylus frenatus [Common House Gecko]; Lepidodactylus lugubris [Mourning Gecko]) on the basis of 15,212 sightings. We compared these count samples to a series of complete censuses we conducted from four or more total removal plots (everything removed to mineral soil) totaling 400 m2 (about 1% of study site) in each of the years 1995, 1999, and 2012, providing time-stamped quantification of detectability for each species. Unfortunately, the actual population trajectories taken by the four species were masked by unexplained variation in detectability. This observation of debilitating latent variability in lizard detectability under nearly ideal conditions undercuts our trust in population estimation techniques that fail to quantify venue-specific detectability, rely on pooled detection probability estimates, or assume that modulation in predefined environmental covariates suffices for estimating detectability.