Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam

Ignacio T. Moore, Michael J. Greene, Darren T. Lerner, Chance E. Asher, Randolph W. Krohmer, David Hess, Joan Whittier, Robert T. Mason

    Research output: Contribution to journalArticle

    22 Citations (Scopus)

    Abstract

    Introduced species are an increasingly pervasive problem. While studies on the ecology and behavior of these pests are numerous, there is relatively little known of their physiology, specifically their reproductive and stress physiology. One of the best documented introduced pest species is the brown tree snake, Boiga irregularis, which was introduced onto the Pacific island of Guam sometime around World War II. The snake is responsible for severely reducing Guam's native vertebrates. We captured free-living individuals throughout the year and measured plasma levels of stress and sex hormones in an effort to determine when they were breeding. These data were compared to reproductive cycles from a captive population originally collected from Guam. Free-living individuals had chronically elevated plasma levels of the stress hormone corticosterone and basal levels of sex steroids and a remarkably low proportion were reproductively active. These data coincide with evidence that the wild population may be in decline. Captive snakes, had low plasma levels of corticosterone with males displaying a peak in plasma testosterone levels during breeding. Furthermore, we compared body condition between the free-living and captive snakes from Guam and free-living individuals captured from their native range in Australia. Male and female free-living snakes from Guam exhibited significantly reduced body condition compared to free-living individuals from Australia. We suggest that during the study period, free-living brown tree snakes on Guam were living under stressful conditions, possibly due to overcrowding and overexploitation of food resources, resulting in decreased body condition and suppressed reproduction.

    Original languageEnglish (US)
    Pages (from-to)91-98
    Number of pages8
    JournalBiological Conservation
    Volume121
    Issue number1
    DOIs
    StatePublished - Jan 2005

    Fingerprint

    Boiga irregularis
    Guam
    snake
    snakes
    body condition
    plasma
    corticosterone
    physiology
    breeding
    pests
    sex hormone
    overcrowding
    captive population
    pest species
    sex hormones
    Pacific Ocean Islands
    testosterone
    reproductive cycle
    steroid
    wild population

    Keywords

    • Boiga irregularis
    • Brown tree snake
    • Guam
    • Introduced pest
    • Stress

    ASJC Scopus subject areas

    • Ecology, Evolution, Behavior and Systematics
    • Ecology
    • Nature and Landscape Conservation

    Cite this

    Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam. / Moore, Ignacio T.; Greene, Michael J.; Lerner, Darren T.; Asher, Chance E.; Krohmer, Randolph W.; Hess, David; Whittier, Joan; Mason, Robert T.

    In: Biological Conservation, Vol. 121, No. 1, 01.2005, p. 91-98.

    Research output: Contribution to journalArticle

    Moore, IT, Greene, MJ, Lerner, DT, Asher, CE, Krohmer, RW, Hess, D, Whittier, J & Mason, RT 2005, 'Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam', Biological Conservation, vol. 121, no. 1, pp. 91-98. https://doi.org/10.1016/j.biocon.2004.04.012
    Moore, Ignacio T. ; Greene, Michael J. ; Lerner, Darren T. ; Asher, Chance E. ; Krohmer, Randolph W. ; Hess, David ; Whittier, Joan ; Mason, Robert T. / Physiological evidence for reproductive suppression in the introduced population of brown tree snakes (Boiga irregularis) on Guam. In: Biological Conservation. 2005 ; Vol. 121, No. 1. pp. 91-98.
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