Food Habits of Boiga irregularis, an Introduced Predator on Guam

• Published in: Journal of herpetology Vol. 22; no. 3; pp. 275 - 282
• Main Author: Savidge, Julie A.
• Format: Journal Article
• Language: English
• Published: Saint Louis, MO Society for the Study of Amphibians and Reptiles 01-09-1988
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Birds; Boiga irregularis; Diet; Eggs; Forest habitats; Fundamental and applied biological sciences. Psychology; Lizards; Mammals; Reptilia. Amphibia; Snakes; Stomach; Urban habitats; Vertebrata; Wildlife ecology; Guam; Vertebrata; Introduced species; Diet; Guam; Micronesia; Reptilia; Mariana Islands; Oceania; Ophidia
• ISSN: 0022-1511; 1937-2418
• DOI: 10.2307/1564150

Introduced brown tree snakes (Boiga irregularis) from a variety of habitats on Guam were examined for prey remains to determine how B. irregularis has maintained its population despite the overexploitation or extinction of its more vulnerable prey, principally birds and small mammals. Stomach and intestinal tract analyses revealed that B. irregularis consumes primarily birds and their eggs, small mammals, lizards, and lizard eggs. The snakes appeared to be somewhat opportunistic in prey choice. No significant differences were found in the overall diets of males and females of the same size classes. Ontogenetic differences in diet were present. Birds and small mammals were consumed by medium to large snakes; the abundance of both of these prey classes has been severely affected by B. irregularis. Small lizards in general are very abundant on Guam and appear to be an important food source for maintaining small to medium-sized snakes. The overlap of lizard and larger vertebrate prey taken by the intermediate-sized snakes allows the snake population to maintain relatively high densities despite the overexploitation of its larger prey.