Hi all!

OSU’s 2015 seabird studies at Yaquina Head resumed the last week of May. As in past years, the field crew is monitoring murre and cormorant reproductive success and murre diets/foraging.  We have also been tracking the movements of 10 adult murres along the coast by satellite telemetry.  In partnership with the U.S. Geological Survey and U.S. Fish and Wildlife Service, we caught these 10 birds at sea just off Yaquina Head in mid-May and attached satellite transmitters to them (a bit more on this project below).

Thus far on the colony, the murres are having a very difficult time incubating eggs, as Bald Eagle disturbances have been very high. We have already lost many of the eggs that we have been tracking – some lasting no longer than a day due to eagle disturbance and consumption by secondary predators (Western Gulls and Common Ravens). The attacks are being made by at least one adult breeding pair and four sub-adult eagles. The eagles’ extended physical presence on both Colony Rock and Flat Top and subsequent disturbances has prevented the murres from coming back onto the colonies and extending their time in the water. As a result, we are finding clear plots in both Flat Top and Colony Rock.  We have observed few eagle-free days, but even during their absence, the murres were constantly alert, standing about on the rocks. 

However, not all is lost! A very small percentage of the sub-colonies (1-5%) have stood their ground against predators.  These are outside of our annual monitoring plots, but will hopefully allow us to collect diet data if chicks hatch! On Flat Top it is the north end and on Colony Rock it is the south end. In both sections we have seen breeding pairs consistently on eggs. Additionally, birds are incubating eggs on Lion’s Head (the tall rock off Cobble Beach) where there have not been many disturbances.  We are monitoring some cormorant nests, but there are very few overall compared to previous years and especially few Pelagic Cormorants.

The seabird tracking work is a new study to help inform offshore spatial planning.  We are tracking several species of birds, including murres.  Over the next year, we will scale up the tag deployments and will be updating our website with tracking information.  For now, see the attached map of 3 murres from the past two weeks. 

Stay tuned for future updates,

Stephanie Loredo

Ian Throckmorton

Oscar Garzon

Carlos Lerma

Jessica Porquez

Amanda Gladics

Rob Suryan