The Seabird Oceanography Lab is almost midway through the field season here at Yaquina Head Outstanding Natural Area. The murres have not been able to incubate eggs this year and we are expecting a year of no reproductive success. We are continuing our monitoring effort and are anticipating starting diet photography efforts soon at the small colony located in Depoe Bay.
When observation began in late May at Yaquina Head, we saw the murres repeatedly flushed from the main nesting site Colony Rock by eagles. Often two sub adult and two adult eagles would also flush Lion’s Head, Seal, and Stegosaurus Rock, and the murres would not return to these areas as quickly. By June, later then we expected, murres began to settle and we spotted birds with eggs on Colony Rock. Although the majority of Colony Rock was covered with birds, two locations at the eastern side closest to eagle’s roost remained unoccupied.
About a week later the avian predator disturbances spiked again. The first one that led to considerable undoing of nesting progress was on June 13th, when three separate groups of turkey vultures flushed murres from the colony. Only one of these groups of vultures was accompanied by bald eagles. These disturbances allowed western gulls to opportunistically take over 30 murre eggs – even dropping some on the ground around the lighthouse. The gull flock continued to grow as on the 17th, we estimated over 50 gulls flying overhead. From then on – apart from the chaotic observation day on June 22nd — it only took one disturbance each observation period for the murres to be completely cleared off. Each time their numbers on colony rock dwindled. When they were present on the rock many were standing and not in their nesting position.
In early July we typically have murre chicks, but this year Colony Rock has been devoid of adult murres and eggs for over a week now. Murres are continuing to raft in the water nearby the colony. There have been some murres attending Stegosaurus Rock and South Headland however they aren’t nesting. Normally, eagle disturbances decline through June, but this year they have been continuing. Additionally, winter conditions persisted through May and upwelling was delayed until June. This likely contributed to the inability of the murres to settle and incubate eggs. Upwelling brings cold nutrient-rich water to the surface that fuels primary productivity and the forage fish murres depend on. Upwelling typically initiates in mid-April prior to when murres lay their eggs.
Unfortunately, the number of nesting Brandt’s and Pelagic cormorants are low this year. Eagles do not disturb them like they do the murres though many gulls roost on Flat Rock where the Brandt’s are nesting. Flat Rock has quite the dynamic rise and fall in nests; On July 6th we had spotted 35 nests. On June 29th we realized that almost half of these had been abandoned – mostly on the Western and top half of the rock. We are currently following 17 active Brandt’s nests. Additionally, we have two Pelagic cormorant nests on Stegosaurus Rock and we are following 15 Pelagic cormorant nests on South Headland.
On the bright side there are three healthy looking chicks on South Headland and we are expecting more on Flat Rock. We’ll make sure to monitor these chicks and keep an eye out for murres though.
We are excited to share with you an update on our nest monitoring of the common murres and cormorants at Yaquina Head Outstanding Natural Area (YHONA). Although our updates were on hiatus in 2020, we are happy to report were able to conduct monitoring. However, there was colony wide reproductive failure as a result of high rates of predator disturbance (bald eagles, 0.58/hour). At one point 15 bald eagles simultaneously hunting at Yaquina Head; a group size that has not been recorded at the site before or since.
This year, we began monitoring efforts in late May. In early July we were monitoring 161 common murre nests, 93 of which had eggs, and 11 of which had chicks. The first chicks hatched on June 28th on Lower Colony Rock and Satellite Rock.
As observed in recent years, bald eagle disturbances were fairly frequent within our Colony Rock nesting plots during the months of May and June. Beginning in July we have seen a noticeable decrease in disturbances. From June 2 – 30 June, 2021 we recorded 41 disturbances. Murres nesting in larger colonies appear to be holding their ground in all plots except for the top eastern half of Colony Rock where adult/sub-adult bald eagles perch periodically, allowing for gulls and turkey vultures to pillage unattended eggs. Flat Top Rock has remained nearly empty for the duration of the breeding season and was not included in this year’s monitoring efforts.
Along with common murre monitoring, we are also monitoring Brandt’s and pelagic cormorants. We are currently monitoring 22 Brandt’s cormorant nests and 37 pelagic cormorant nests. Chicks began hatching the week of July 5th and the majority of our nests for both species now have chicks.
We look forward to updating you on the success of our nests in August.
This year, we’re delighted to have the addition of several new (and returning) lab members including Laney Klunis, a 2021 Research Experience for Undergraduates Intern from California State University Monterey Bay; Edward Kim, the 2021 Intern at Bureau of Land Management; Alyssa Nelson, USFWS Intern and former undergraduate lab member; and Noah Dolinajec, student in the Graduate Certificate in Wildlife Management (OSU) program are conducting field work for the 2021 YHONA season. We are pleased to be up and running with a full field team this year!
Welcome to the blog of the Seabird Oceanography Lab. We engage in seabird science research along the Oregon coast, and worldwide. This blog will be used to provide updates on fieldwork, research, and anything seabird related! We may occasionally discuss seals. Please visit us again!
Previous Blog Posts
Over the past few years, our members periodically wrote blogs about our research for other venues. Follow the links below to blog posts written by members of the Seabird Oceanography Lab.
A series of blog posts written in collaboration with the Seabird Youth Network about red-legged kittiwakes (link). Followed by updates by Seabird Youth Network interns that includes resighting banded red-legged kittiwakes (link). Our recent project with red-legged kittiwakes occurred during three years of successively worse breeding success. This blog posted in 2017, was written by Rachael Orben as she contemplated why the red-legged kittiwakes nesting on St. George Is., AK did not lay eggs.
A blog describing Stephanie Loredo’s research on common murre movements on the Oregon coast.
Thoughts on western gull foraging preferences by Stephanie Loredo (link), along with a summary of western gull at-sea distributions relative to coastal marine reserves authored by Rob Suryan (link).
Midway Atoll is home to the largest albatross colony in the world. A visit there can be more than overwhelming. Here are links to two blogs written by Rachael Orben after two, two-week visits to study albatross foraging ecology. Blog one and blog two.