San Francisco Bay NWR Complex
Pacific Southwest Region

The Murre Maniac
The Common Murre Project Update April 2009

Breeding Season at Devil’s Slide


This month Common Murres have been seen attending Devil’s Slide Rock every day. The murres are getting ready for the breeding season! They are busy finding a mate and defending their territories. Murres nest together in large colonies for protection from predators like gulls. C olonies are closely packed groups of nesting seabirds. Murre colonies are located on s teep cliffs of rocky islets and islands. These areas are inaccessible to mammal predators, which make for a great place to lay an egg and raise a chick.

Murres usually return to lay an egg on the same spot every year! They like wide ledges where many birds can nest next to each other, wing to wing. Mates greet one another by bowing their heads and preening each other. W e have counted 156 pairs within the three monitored plots on Devil’s Slide Rock. Our high count of 819 murres was recorded on April 27 th. Many murres are attending the rock but so far we have not seen any eggs.

The breeding season seems to be starting later for Brandt’s Cormorant’s this year. They have not begun to build nests yet. T his could mean that the birds are having a more difficult time finding food. Cormorants eat fish, they use their webbed feet to swim and catch prey. We hope to see both Common Murres and Brandt’s Cormorants laying eggs soon.

April 2009 Colony Counts of Devil’s Slide Rock
# Murres
April 2
April 16
April 20
April 23
April 25
April 27
April 29

*Compiled by Lisa Eigner

Last updated: September 1, 2011