Reproductive condition of an invasive snake in urban, savanna, and forest habitats

NeoBiota
By: , and 

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Abstract

Predation by Brown Treesnakes (Boiga irregularis) has caused the decline or extinction of all native forest vertebrates on Guam, including birds, lizards, and bats. Loss of the highest-quality prey has caused shifts in Brown Treesnake size and life history. We sought to understand how reproductive condition varies among habitats island-wide, particularly comparing urban and savanna habitats (where some primarily non-native large prey remain) with prey-depauperate forest habitats. We dissected 100 snakes from each of 18 sites stratified by 6 habitat types and calculated a body condition index, relative follicle size (for females; N = 817) and relative testes size (for males; N = 992) for each. Low detection of reproductive females continues to hamper research on their biology, as only 11% of females had secondary vitellogenic follicles (N = 89). Although variation among sites within habitats was high, above-average reproductive development of both males and females was most frequently observed in urban and savanna habitats, emphasizing the potential for prey subsidies in these habitats to fuel population growth and affect invasive snake management objectives. Furthermore, the trade-off between body condition and reproductive condition appeared to be more severe in forested habitats and less severe in urban habitats for both males and females. There were few obvious seasonal patterns, although there was a slightly lower probability of females having secondary vitellogenic follicles in the wet season compared to the dry season.

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Publication type Article
Publication Subtype Journal Article
Title Reproductive condition of an invasive snake in urban, savanna, and forest habitats
Series title NeoBiota
DOI 10.3897/neobiota.100.148230
Volume 100
Publication Date August 06, 2025
Year Published 2025
Language English
Publisher Pensoft
Contributing office(s) Pacific Island Ecosystems Research Center
Description 26 p.
First page 109
Last page 134
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