The Brown Treesnake is a highly destructive reptile species that has extirpated many native species of birds, bats, and lizards from the U.S. Territory of Guam. For more than two decades branch scientists with the Invasive Reptile Project have developed, validated, and tested the feasibility of Brown Treesnake control and suppression at various spatial scales.
An important aspect of our research is increasing the efficacy of control tools (rodent-baited traps, toxicants delivered aerially and by bait tubes, and visual searches). Our recent island-wide visual surveys along road edges have revealed a high proportion of juvenile snakes across Guam; this is an important finding because juveniles consistently evade our control tools. To further understand juvenile distribution, we are attempting to learn habitat associations for these juveniles by conducting visual surveys on forest edges and interiors. Increased understanding of juveniles is crucial because a large proportion of Brown Treesnakes escaping Guam on cargo, ships, and airplanes are juveniles.
Landscape-scale suppression techniques have improved because of new control technologies developed by U.S. Department of Agriculture (USDA) and partner agencies, chiefly aerial delivery of toxicant-loaded bait. Our scientists are contributing to the development of these methods through control tool validation (for example, confirming that the tool is functioning to eradicate all vulnerable individuals) and by modeling the optimal timing of successive toxicant drop applications.
Our cooperators include U.S. Department of the Interior Office of Insular Affairs, U.S. Fish and Wildlife Service (USFWS), U.S. Navy, U.S. Air Force, Guam Division of Aquatic and Wildlife Resources, USDA Wildlife Services, Hawaii Department of Agriculture, Hawaii Department of Forestry and Wildlife, and Commonwealth of the Northern Mariana Islands Department of Fish and Wildlife.
Below are other science projects associated with this project.
USGS Brown Treesnake Laboratory - Guam
Brown Treesnake Rapid Response Team
Below are multimedia items associated with this project.
Below are publications associated with this project.
Invasive Brown Treesnake movements at road edges indicate road-crossing avoidance
Geographic distribution: Boiga irregularis (Brown treesnake)
Marsh rabbit mortalities tie pythons to the precipitous decline of mammals in the Everglades
Movements and activity of juvenile Brown Treesnakes (Boiga irregularis)
Invasive and introduced reptiles and amphibians
Selective predation by feral cats on a native skink on Guam
Genetic analysis of a novel invasion of Puerto Rico by an exotic constricting snake
Ecological correlates of invasion impact for Burmese pythons in Florida
Consumption of bird eggs by invasive Burmese Pythons in Florida
Do predators control prey species abundance? An experimental test with brown treesnakes on Guam
Divergence in morphology, but not habitat use, despite low genetic differentiation among insular populations of the lizard Anolis lemurinus in Honduras
Alien reptiles and amphibians: a scientific compendium and analysis, by Fred Kraus
Below are partners associated with this project.
- Overview
The Brown Treesnake is a highly destructive reptile species that has extirpated many native species of birds, bats, and lizards from the U.S. Territory of Guam. For more than two decades branch scientists with the Invasive Reptile Project have developed, validated, and tested the feasibility of Brown Treesnake control and suppression at various spatial scales.
An important aspect of our research is increasing the efficacy of control tools (rodent-baited traps, toxicants delivered aerially and by bait tubes, and visual searches). Our recent island-wide visual surveys along road edges have revealed a high proportion of juvenile snakes across Guam; this is an important finding because juveniles consistently evade our control tools. To further understand juvenile distribution, we are attempting to learn habitat associations for these juveniles by conducting visual surveys on forest edges and interiors. Increased understanding of juveniles is crucial because a large proportion of Brown Treesnakes escaping Guam on cargo, ships, and airplanes are juveniles.
Landscape-scale suppression techniques have improved because of new control technologies developed by U.S. Department of Agriculture (USDA) and partner agencies, chiefly aerial delivery of toxicant-loaded bait. Our scientists are contributing to the development of these methods through control tool validation (for example, confirming that the tool is functioning to eradicate all vulnerable individuals) and by modeling the optimal timing of successive toxicant drop applications.
Our cooperators include U.S. Department of the Interior Office of Insular Affairs, U.S. Fish and Wildlife Service (USFWS), U.S. Navy, U.S. Air Force, Guam Division of Aquatic and Wildlife Resources, USDA Wildlife Services, Hawaii Department of Agriculture, Hawaii Department of Forestry and Wildlife, and Commonwealth of the Northern Mariana Islands Department of Fish and Wildlife.
- Science
Below are other science projects associated with this project.
USGS Brown Treesnake Laboratory - Guam
USGS scientists and staff associated with the Brown Treesnake Project are co-located at the Guam National Wildlife Refuge at the northern end of Guam in the western Pacific Ocean. Project staff work on developing and testing control tools for invasive brown treesnakes, as well as understanding their impacts on Guam's ecosystems. Project staff also lead the multi-agency Brown Treesnake Rapid...Brown Treesnake Rapid Response Team
Brown Treesnakes continue to cause major problems for the ecology, economy, and quality of life on Guam. Our scientists conduct research on this snake species, including control tool development and testing, ecological impacts, and early detection methods. We hold Brown Treesnake Rapid Response Team training courses on Guam throughout the year to develop the skills needed to effectively respond to... - Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with this project.
Filter Total Items: 27Invasive Brown Treesnake movements at road edges indicate road-crossing avoidance
Roads have significant impacts on the dispersal of wildlife. Although this poses a threat to the abundance and diversity of desirable flora and fauna, it also affords some opportunity for enhancing control of invasive species. Roads are the most common terrain features that may affect the rate of landscape-scale movements of invasive Brown Treesnakes (Boiga irregularis) throughout Guam. We radio tGeographic distribution: Boiga irregularis (Brown treesnake)
Rota: Rota Seaport (14.136502°N, 145.135351°E; WGS84). 3 September 2014. Shelwyn Taisacan, Robert Ulloa. Verified by G. Zug. USNM 581745. Snake (42 g, 810 mm SVL, 1020 mm total length) captured in a mouse-baited trap hung on the fence perimeter of the Rota Seaport. Because the Northern Marianas Islands are historically snake-free, these traps are used around ports and airports for early detectionMarsh rabbit mortalities tie pythons to the precipitous decline of mammals in the Everglades
To address the ongoing debate over the impact of invasive species on native terrestrial wildlife, we conducted a large-scale experiment to test the hypothesis that invasive Burmese pythons (Python molurus bivittatus) were a cause of the precipitous decline of mammals in Everglades National Park (ENP). Evidence linking pythons to mammal declines has been indirect and there are reasons to question wMovements 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),Invasive and introduced reptiles and amphibians
Why is there a section on introduced amphibians and reptiles in this volume, and why should veterinarians care about this issue? Globally, invasive species are a major threat to the stability of native ecosystems,1,2 and amphibians and reptiles are attracting increased attention as potential invaders. Some introduced amphibians and reptiles have had a major impact (e.g., Brown Tree Snakes [Boiga iSelective predation by feral cats on a native skink on Guam
Two species of skinks (Fig. 1) occur in a 5-ha plot on Guam where we have been conducting intensive research on Brown Treesnake (Boiga irregularis) population biology for nearly a decade (Rodda et al. 2007). The Pacific Blue-tailed Skink (Emoia caeruleocauda [de Vis 1892]) is native to Guam, whereas the Curious Skink (Carlia ailanpalai Zug 2004) is invasive. On the evening of 27 November 2012, PMLGenetic analysis of a novel invasion of Puerto Rico by an exotic constricting snake
The tropical island Puerto Rico is potentially vulnerable to invasion by some species of exotic snakes; however, until now no established populations had been reported. Here we report and genetically characterize the nascent invasion of Puerto Rico by an exotic constricting snake of the family Boidae (Boa constrictor) using mtDNA and microsatellite data. Over 150 individual B. constrictor have beeEcological correlates of invasion impact for Burmese pythons in Florida
An invasive population of Burmese pythons (Python molurus bivittatus) is established across several thousand square kilometers of southern Florida and appears to have caused precipitous population declines among several species of native mammals. Why has this giant snake had such great success as an invasive species when many established reptiles have failed to spread? We scored the Burmese pythonConsumption of bird eggs by invasive Burmese Pythons in Florida
Burmese Pythons (Python molurus bivittatus or P. bivittatus) have been reported to consume 25 species of adult birds in Everglades National Park, Florida (Dove et al. 2011), but until now no records documented this species eating bird eggs. Here we report three recent cases of bird-egg consumption by Burmese Pythons and discuss egg-eating in basal snakes.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) predationDivergence in morphology, but not habitat use, despite low genetic differentiation among insular populations of the lizard Anolis lemurinus in Honduras
Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards acrossAlien reptiles and amphibians: a scientific compendium and analysis, by Fred Kraus
No abstract available. - Partners
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