Here’s the latest update I wrote about the Common Murres at Yaquina Head:
We had some exciting news this past Thursday we held the day-long Common Murre chick activity watch from 5:30 a.m. to 9:30 p.m.! With the help of several volunteers and the lab crew, we assessed the chick feeding rates, the adult foraging trip durations, and the diet composition of the chicks on the lower rock adjacent to Colony Rock. Overall, we followed 10 chicks throughout the day. On average these chicks were fed twice a day and consumed primarily smelt, a small type of forage fish. Interestingly, three of the chicks we monitored did not get fed over the course of the day. We also saw a total of two disturbances during the day-long chick activity watch, induced by Turkey Vultures and Western Gulls.
In other news, we are currently following five nests in our remaining plot, and have four chicks and one egg. We expect these chicks to fledge in the upcoming days, as murre chicks typically fledge 15-25 days after hatching. Two of our chicks are at the fledgling stage; the other two will be by mid next week. Since the last update, we have also seen a drastic decline in Bald Eagle disturbances. The last recorded disturbance was on July 13th, but this does not rule out disturbances during the later hours when monitoring does not take place. Overall, Common Murres are still densely populating both Flat Top and Colony Rock but, based on last year’s data book, the murres may be departing soon enough. They were gone by July 28, 2015.
Prey photos have also been taken these past weeks to assess murre diets. So far, we’ve snapped over 100 prey photos of murres bringing fish back to the colony. A few of these fish were brought to chicks on lower Colony Rock, but most were paraded around on the top of Colony Rock or Flat Top Rock by birds without eggs or chicks. The overwhelming majority of prey were smelt species, with a single clupeid (family of herring, anchovy) and a single ammodytid (family of sandlance) thrown into the mix. Lastly, cormorant monitoring has been ongoing. We have observed 43 Brandt’s Cormorant chicks and 41 Pelagic Cormorant chicks thus far. Overall, chick development varies widely. The majority of Brandt’s chicks have almost reached adult size, while the pelagic chicks are younger therefore smaller. Unfortunately, we also have lost six Brandt’s nests and one pelagic nest, all of which were on South Headland, most likely due to Bald Eagle disturbances. Make sure to stay tuned for the next update!