You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
The Effects of Rat (Rattus rattus) Predation on the Reproductive Success of the Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll
Nanette W. H. Seto and Sheila Conant
Vol. 19, No. 2 (1996), pp. 171-185
Published by: Waterbird Society
Stable URL: http://www.jstor.org/stable/1521854
Page Count: 15
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
The breeding population of the Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll has declined dramatically since the accidental introduction of the black rat (Rattus rattus). During 1993 and 1994, we examined the effects of rat predation on Bonin Petrel reproductive success by monitoring nesting petrels in six study sites, three of which were treated with rodenticide (treatment) and three that were not (control). Results indicate that the incubation stage of the petrels' nesting cycle is most vulnerable to rat predation. Both unattended and incubated eggs were attacked by rats. Rat predation was not observed on petrel chicks in study nests. However, incidental observations of chick remains outside of burrows suggest that rat predation on chicks may occur, but at a low frequency. Sites with low burrow density suffered more from rat predation than sites with higher burrow density. The rodenticide "Vengeance™" appeared to successfully suppress the rat numbers in treated sites. The number of nests that failed due to rat predation was significantly lower in two of the three treatment sites when compared with their paired control sites. In addition, the indications of rat activity were lower at these two treatment sites than at the paired control sites. Therefore, this study provides some evidence that rodenticide application is successful in reducing the number of rats, which in turn reduces the amount of rat predation and is associated with an increase in the reproductive success of Bonin Petrels.
Colonial Waterbirds © 1996 Waterbird Society