Fish & Wildlife Service
California/Nevada Operations Office
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2005 Farallon National Wildlife Refuge News Update
A
at a Glance
SEABIRDS
After several excellent seasons, seabirds had a poor reproductive year in 2005. Cassin’s auklets and pelagic cormorants had near total nest failure, while rhinoceros auklets, pigeon guillemots, and common murres had the lowest breeding success since the 1998 El Nino. Brandt’s cormorants were the exception. Exceptionally warm water resulted from a lack of upwelling at the continental shelf. The warm water led to low prey availability for seabirds in the area.
Though many species had poor years, it is important to remember seabirds are very long lived birds. One poor year will have little or no population level impact providing following years are better. For example, a western gull banded as a chick 33 years ago returned and claimed his territory this year. Ashy storm-petrels are also known to live past 30 years. Common murre numbers approached 200,000 individuals including non-breeders this year.
Summarized from:
Population size and reproductive performance of seabirds on Southeast Farallon Island, 2005. PRBO Conservation Science report to the US Fish and Wildlife Service.
MARINE MAMMALS
Twenty-four northern fur seal pups were observed August 25 th. The first fur seal pup since 1817 was born on the Farallons in 1990. The 24 pups this year is a substantial increase from the 11 pups in 2004 and eight in 2003.
A sea otter was observed on October 4 th, only the 3 rd island record.
OTHER SPECIES NOTES
Three burrowing owls were successfully trans-located to another refuge unit in Fremont, CA to prevent them from preying on ashy storm-petrels in the winter. Owls attempting to over-winter ultimately starve or are killed by western gulls in most cases.
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