Ontogenetic and ecological variation in invasion risk of Brown Treesnakes (Boiga irregularis) on Guam

Management of Biological Invasions
By: , and 



Size structure within populations of invasive species may have consequences for relative risk at all stages of the invasion process, with implications for management interventions such as interdiction, suppression, and eradication. To assess relative distributions of invasive Brown Treesnakes among demographic categories of management interest, we undertook the most comprehensive and controlled sampling in >25 years of research into this ecologically and economically destructive introduced predator. We collected a seasonally-balanced sample of 100 snakes from each of 18 sites, stratified by six habitat types, encompassing the species’ entire extralimital range. Samples indicated significant differences in distributions of female and male snakes among management classes (juvenile, transitional, and mature) by site and habitat. We found substantial heterogeneity in localized population characteristics over relatively small geographic distances, only modest influence of habitat type, higher prevalence of reproductively mature snakes in savanna and urban habitats, and an alarmingly high proportion of snakes that are too small to be effectively targeted by current rodent-baited control tools (mean = 38.2%, range = 19 to 72%). Failure to account for such variability in high risk demographic fractions may hinder successful interventions.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Ontogenetic and ecological variation in invasion risk of Brown Treesnakes (Boiga irregularis) on Guam
Series title Management of Biological Invasions
DOI 10.3391/mbi.2017.8.4.02
Volume 8
Issue 4
Year Published 2017
Language English
Publisher REABIC
Contributing office(s) Fort Collins Science Center
Description 15 p.
First page 469
Last page 483
Country United States
Other Geospatial Guam
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