Impacts of introduced Norway rats (Rattus norvegicus) on least auklets (Aethia pusilla) breeding at Kiska Island, Aleutian Islands, Alaska during 2001-2003
I quantified impacts of non-indigenous Norway rats on Least Auklets breeding at Kiska Island. Little direct evidence of rat predation was found in my productivity crevices, nevertheless hundreds of rat-predated Least Auklet adults, chicks and eggs were found at the auklet colony and in rat hoards. M...
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Format: | Thesis |
Language: | English |
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Memorial University of Newfoundland
2004
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Online Access: | https://research.library.mun.ca/10968/ https://research.library.mun.ca/10968/1/Major_HeatherLynn.pdf |
Summary: | I quantified impacts of non-indigenous Norway rats on Least Auklets breeding at Kiska Island. Little direct evidence of rat predation was found in my productivity crevices, nevertheless hundreds of rat-predated Least Auklet adults, chicks and eggs were found at the auklet colony and in rat hoards. My estimate of adult Least Auklet survival from Kiska (0.88 in 2001- 2002) was similar to values estimated by others. Yet in these years reproductive success was the lowest ever recorded (0.16 and 0.09) in the Aleutians. Norway rats foraging within the auklet colony were larger in size and showed increased reproductive activity than those foraging off the auklet colony. A simple population viability analysis, using current vital rate estimates, revealed that Least Auklets on Kiska are likely experiencing a rapid population decline. Continued monitoring and mitigation plans are required to further address the impacts of rats on auklets at Kiska. |
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