A comparison of three trap designs for capturing brown treesnakes on Guam
Daniel S. Vice A , Richard M. Engeman B and Diane L. Vice A CA United States Department of Agriculture, Wildlife Services, 1060 Route 16, Suite 103C, Barrigada Heights, GU 96913, USA.
B National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA.
C Current Address: Guam Department of Agriculture, Division of Aquatic and Wildlife Resources, 192 Dairy Road, Mangilao, GU 96923, USA.
Wildlife Research 32(4) 355-359 https://doi.org/10.1071/WR04046
Submitted: 26 May 2004 Accepted: 19 April 2005 Published: 5 July 2005
Abstract
The accidental introduction of the brown treesnake (Boiga irregularis) to Guam has resulted in the extirpation of most native terrestrial vertebrates on the island, thousands of power outages, and significant ecological changes. In addition, Guam now serves as a source population for the dispersal of snakes to other islands. Control of the brown treesnake is dependent upon the use of traps in a variety of settings, including port environments and in forested habitat. A variety of snake traps have been used on Guam; most consist of a modified crawfish or minnow trap, housing a live mouse that serves as a lure. We compared the efficacy of three trap styles: (1) a two-piece design with a separate internal mouse chamber; (2) a one-piece trap, with design improvements aimed at decreasing handling; and (3) the same one-piece trap, fitted with a PVC-coated wire-mesh entrance flap. Data collected included snake capture rates, snake size distribution, mouse survival, and trap maintenance time. Snake capture rates did not differ between the one-piece and the two-piece traps, although capture rates were significantly lower in the PVC-flap traps. The average snake size or distribution of snake sizes did not differ between the one-piece and two-piece traps. Handling times, both with and without a snake in the trap, were significantly lower for the one-piece trap. Mouse survival did not differ between the one-piece and two-piece trap styles. Our results indicate that the modified one-piece trap design provides several advantages over previous trap designs.
Acknowledgments
We thank E. W. Campbell III., C. S. Clark, L. Clark, J. A. Lynch, M. E. Pitzler, P. J. Savarie and two anonymous reviewers for their helpful comments on this manuscript. This project was conducted under funding provided to the USA Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Washington State Director’s Office, by the USA Department of Defence, under DOD MIPR-064-95, ‘Operational Control of Brown Tree Snakes in Guam’.
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