Category: Yaquina Head

Posted on

To Fledge or Not to Fledge: Yaquina Head End of Season Update, Summer 2024

By Hannah Motta, Environment for the Americas Intern at Yaquina Head Outstanding Natural Area

Although it’s not the typical rainy season that signals the end of summer here, we officially wrapped up our Yaquina Head field season on the morning of August 16th. My name is Hannah, and I’m an Education and Outreach Intern with Environment for the Americas, stationed at Yaquina Head. I recently graduated from the University of Oregon with a B.S. in Environmental Science and a B.A. in Spanish, where I focused on environmental education. My goal has always been to inspire people to care about nature through birds, which ultimately brought me here to Yaquina Head.

Figure 1. Environment for the Americas Intern Hannah Motta at Cobble Beach at Yaquina Head Outstanding Natural Area during low tide.

In my current role, I work as an interpretive park ranger and assist our facilities operations manager on the maintenance team at Yaquina Head Outstanding Natural Area. Throughout the summer I assisted Oregon State’s Seabird Oceanography Lab in monitoring cormorant, gull, and murre colonies at Yaquina Head and Depoe Bay.

As we predicted in our earlier posts from this spring, this year was a “bust” for Pelagic Cormorants, while Brandt’s Cormorants had a much more positive outcome. The Common Murres, however, experienced dramatically different results between Yaquina Head and Depoe Bay, largely due to high rates of Bald Eagle predation. As you may have noticed throughout this season, Bald Eagles have taken center stage as some of the main characters.

Since most people prefer to get the bad news out of the way first, let’s start with what happened—or more accurately, what didn’t happen—with the Murres at Yaquina Head. Frequent eagle disturbances caused the Murres to flush for hours at a time, leaving very few eggs laid in visible areas. Of the nests we were able to observe, we followed 38 across three different plots. Out of those 38 nests, only two eggs successfully hatched and fledged. A few Murre chicks may have taken shelter in the nooks and crannies of Whale Rock to avoid predation, but overall, we were left with a mere 5% reproductive success rate—a somber finale for the Murres at Yaquina Head.

Now for the much happier news from Depoe Bay! With far fewer eagle disturbances, the Murres had a much better outcome. We monitored 75 Murre nests across five plots, and an impressive 93% of all chicks survived to fledge! Throughout the year, we documented adults bringing back lots of smelts, flatfishes, and sandlance to their chicks, likely fueling the high fledging success rates we witnessed.

Figure 2. Common Murre chick in Depoe Bay with a Brandt’s Cormorant behind.

And yes, as I mentioned earlier, the eagles were causing quite a bit of drama this year. They even managed to prey on some adult cormorants and chicks, which we don’t typically observe. Back at Yaquina Head, we tracked the progress of 27 Pelagic Cormorant nests and 45 Brandt’s Cormorant nests.

The Pelagic Cormorants nested nearly two weeks later than usual at Yaquina Head (long-term average hatch date: July 11th; 2024 median hatch date: July 28th) later than usual and had low reproductive success. Only 15 of the 27 nest structures visible at Yaquina Head had eggs, and these had an average clutch size of 2.7 eggs per nest. Sadly, only 12% of those eggs hatched in late July, and only two nests managed to fledge chicks.

Figure 3. Pelagic Cormorant nesting on cliffside.

But here’s the good news! The Brandt’s Cormorants had a much more successful season. Out of 45 nests monitored, eggs were laid in 37, with the average clutch size being a very respectable 3.1 eggs per nest. On average, each nest fledged 2.1 chicks, which is well above the long-term average, though slightly lower than last year’s record-breaking 2.4 chicks per nest.

Interestingly, despite variable eagle predation between our two sites (typically high at Yaquina Head, low at Depoe Bay) our cormorants did very similarly at both colonies. Although we observed a few instances of eagles preying on cormorant chicks at both sites, it appears the impact this predation had on cormorant nesting success was either minimal, or more even between sites than disturbance to murres was. We’ll have to watch out next year to see if eagles continue to prey on cormorant chicks and these birds will face any population-level impacts like cormorants in British Columbia have in recent decades (Carter et al. 2018).

Figure 4. Brandt’s Cormorant and Common Murre at Depoe Bay through the spotting scope.

The 2024 seabird monitoring season at Yaquina Head was a mixed bag; while we observed poor reproductive performance for both Pelagic Cormorants and Common Murres, the Brandt’s Cormorants had a great season. What’s more, the Depoe Bay Murres thrived, seemingly unaware of the struggle their conspecifics faced just ~15km south! But now, both colonies appear starkly quiet and empty; it’s time to start looking forward to the day the rocks and cliffs are covered by breeding seabirds once more.

I’d like to thank you all for your support of the Yaquina Head Seabird Monitoring Program and want to extend a huge thanks to the amazing team I had the opportunity to work with—Aya, Travolis, and Will. You all made getting up extremely early and standing in the cold by far some of my favorite memories this summer.

Thanks for keeping up, and see you all next year!

Figure 5. Awesome Yaquina Head Seabird Monitoring team. Pictured from left to right: Aya, Travolis, Will and Hannah.

Posted on

Notes from the field: Seabird Predators on Oregon’s South Coast

By Travolis Williams, Oregon State University undergraduate

Was sup everyone,

My name is Travolis Williams. I am a Junior currently at Oregon State University. I am originally from St. Louis, Missouri. I came to Oregon to pursue a degree in marine biology and found this once in a lifetime opportunity with VIEW fellowship this past February. I intern with the Seabird Oceanography Lab at the Hatfield Marine Science Center.                    

Seabird Oceanography Lab intern Travolis Williams (right) helps field assistant Colton Veltkamp collect river otter scat samples.

I currently work on two projects within the department. One being monitoring seabirds along the coast at Yaquina head and Depoe Bay surveying the two colonies with Common Murres, Pelagic Cormorants, Brandt’s Cormorants, and the Western Gull (Field work). The data gathered in this project is extremely specific and has been tracked for an extended amount of time making it equally as important as it is relevant and up to date. I have had the wonderful opportunity to work under Rachael Orben, William Kennerley, and his additional intern, Aya Attal to observe the unique behaviors and aspects of each of these species of enticing birds.

The second project is processing fecal matter from otter communities along rivers and estuaries in southern Oregon. The scat, as we call it, is collected so the scat’s compenets can be identified via microscope in order to assess river otter diet. River otters are generalist predators that sometimes feed not just on fish and invertebrates, but also on breeding seabirds. We collect these scat samples because Luke, the cool graduate student whose project it is, surveys the dynamic of otter predation on Leach’s Storm-petrels. Storm-petrels are a very ecologically important species because they play a vital role in being an indicator of the current environmental conditions that they are accustomed to. Furthermore, they are needed to maintain the ecosystems they are a part of.

Recently, I had a chance to go to the Port Orford Field Station, a research facility staffed by OSU (Oregon State University) and USDA, and it was and wonderful experience. I was only there for three days total but had so much fun. As far as work goes, we went kayaking down the Chetco River where I could do fieldwork with Luke S., the graduate student, collecting otter scat along the river’s banks. I learned that otters defecate on rocks called latrines and are also used for socializing and scent marking. It was also my first-time kayaking which was incredibly fun for me.

The next day we did in-land work to give us a break from the water and ran into an amazing group of otters in the water and while collecting scat me, Luke, and his assistant Colton ran into a wild otter that was no more than 6 feet from us before it calmly turned around. The final day we went kayaking down Coos Bay river where we did not find much otter scat, but I did learn that raccoons and otter most likely have some sort of relationship with one another because we found that raccoons and otters use the same latrines. I also learned that waves are not anything to be taken lightly because being on a wave crest a foot off the surface of the water is not all too fun when you are an amateur kayaker.

The field team (clockwise from bottom: Travolis Williams, Colton Veltkamp, and M.S. student Luke Stuntz) on the coast near Gold Beach, Oregon. Offshore is Hunter’s Island, one of the largest Leach’s Storm-Petrel colonies in the region, where predators like river otters have been recently recorded.

Overall, the trip was amazing, and the trip was one of a kind. Even the staff in the facility were wonderful. We had a chance to go free diving and even went everyone was all in from work before bed we would watch a movie that everyone would enjoy.

Posted on

Yaquina Head Mid Season Update, Summer 2024

By Aya Attal, NSF REU Intern, Portland State University

While spring is usually the season of change for most things, there’s been a lot of change over on the Oregon Coast this summer, too! A lot of change for me, certainly– my name is Aya Attal, and I go to school at Portland State University. However, I’ve been living in Newport this summer and working as an REU intern in Rachael Orben’s lab at Oregon State University, studying seabirds at Yaquina Head and Depoe Bay. And while there is a lot of change for me, there is even more change for the seabirds this summer; we’ve noticed a lot of improvement in the outlook of the breeding activities in the murres, cormorants, and gulls at Yaquina Head (Newport) and Pirate Cove (Depoe Bay). 

A lot has happened over a few short weeks at Yaquina Head (Figure 1) this summer, even since the last update on June 11th.

Figure 1. Yaquina Head at 6am. Whale Rock can be seen at the bottom. The lone (?) murre chick at Yaquina Head is located in a protected crevice low on the rock.

While there are adult murres regularly present on three of the rocks at Yaquina Head, eagle disturbances have kept many of the adults from comfortably being able to incubate eggs. A juvenile and adult bald eagle regularly fly down towards the rocks, causing murres to “abandon ship”. This leaves many eggs vulnerable to predators. This behavior from the murres is called flushing, and is characterized by the murres flying off the rocks to raft in the water in droves in order to escape predators. Unfortunately, this leaves their eggs open to predation by the opportunistic gulls!

In recent years, we’ve noticed that eagle disturbance decreases as the summer goes on, and eagles have been observed only infrequently since the start of July. A small spree of murre egg-laying followed in early July yet these eggs were all lost within a few weeks to predators. Although murres are attending the colony more often now, we have not had new eggs in our plots since July 18th. Although at least one murre chick has hatched in an obscure crack at the base of Whale Rock – well sheltered from aerial predators – eggs elsewhere at Yaquina Head have all been predated. However, the continued presence of murres at the colony suggests that the possibility of breeding cannot yet be ruled out (Figure 2).

While there may not be any chicks in our Yaquina Head plots, murre chicks have been sighted at Depoe Bay since July 9th. This is good news! The chicks have survived at high rates and we expect the first of them to fledge by the end of the month. We have also started our diet observations for murre chick diets and have since observed smelts, flatfishes, and sand lance being delivered to chicks at Depoe Bay.

Figure 2. Some of the murres in this image from Yaquina Head are exhibiting behavior that corresponds to sitting on top of an egg. Leaning forward with their wings cocked out a little, murres spend a lot of time on top of their eggs, due to the fact that they have no nests whatsoever. 

Earlier in the season, we thought that Pelagic Cormorants wouldn’t be breeding this year, and only a single active Pelagic cormorant nest was observed at the start of June. However, a small group of them have begun nesting at Yaquina Head’s Whale Rock since July 3rd, with the number of nests increasing since then. We are now following 15 Pelagic Cormorant nests at Yaquina Head and 20 nests at Depoe Bay, where nesting was also initiated extremely late. The lone nest from June now has two, three week old chicks and the numerous late nests ought to be hatching soon.

While murres and Pelagic Cormorants may have been initially having a little trouble, many of the Brandt’s Cormorants have been very productive over the last few weeks. Brandt’s Cormorants chicks began hatching June 16th (Yaquina Head) and July 2nd (Depoe Bay). The earliest chicks are already starting to get too large to fit in their nests, with some chicks at Yaquina Head considered to be fully fledged (> 25 days of age). It looks like it will be another successful year for Brandt’s Cormorants on the central Oregon Coast.

Western Gulls are also doing well at both Yaquina Head and Depoe Bay, with many of the chicks already becoming much too active to keep a close eye on. The chicks have been getting very adventurous (Figure 3), with some getting a bit too mobile to continue monitoring. We followed 23 gull nests in total at Depoe Bay, 52% of which succeeded in hatching chicks. We followed 9 gull nests at Yaquina Head, where 67% of them hatched chicks.

Figure 3. Western Gull chicks at Depoe Bay, spotted to be camouflaged with the rock surrounding them! 

As for other seabirds, there’ve been a few Black Oystercatchers at both sites, and while their nests aren’t visible this year, I’ve been seeing them poke their heads out every now and again, especially around Depoe Bay. There have also been Caspian Terns seen flying overhead at Yaquina Bay. Both the terns and oystercatchers will be heard before they are seen in most cases, so make sure to keep an ear out for their calls.

Finally, in other very exciting news, we’ve also spotted a few Tufted Puffins flying around Yaquina Head (Figure 4)! Our last sighting was July 8th– which, coincidentally, is around the same time as the last sighting of tufted puffins at Yaquina Head last year, with 2023’s last tufted puffin sighting being July 9th. Their presence at Yaquina Head doesn’t necessarily mean they’re nesting there this year, though, as the puffins have not been seen bringing food back to nests at any of the surrounding rocks. But it’s still exciting to see them around the area.

Figure 4. Tufted puffin in flight. There are no signs that tufted puffins are breeding at Yaquina Head this year, even if they have been sighted there repeatedly.

Overall, while things may have seemed rather worrisome at the beginning of the season, there is some hope now that there will be Pelagic Cormorant chicks and (perhaps) a few murre chicks at Yaquina Head. The situation appears to be rosier at Depoe Bay, with an abundance of murre, cormorant, and gull chicks at that colony. Overall – between our breeding seabirds and visiting Caspian Terns and Tufted Puffins – it’s shaping up to be a pretty eventful season for seabirds along the Oregon Coast at Yaquina Head and Depoe Bay.

Posted on

To Breed or Not to Breed

Yaquina Head Early Season Update, Summer 2024

It’s the start of another summer on the Oregon Coast and I once again find myself spending most mornings out on rocky headlands for another season of seabird monitoring. Since early May, I’ve been following the breeding activities of murres, cormorants, and gulls at Yaquina Head (Newport) and Pirate Cove (Depoe Bay). As the season begins to take shape, I wanted to share what I’ve been seeing through my spotting scope.

Initial signs are mixed, but seemingly point to a year of low to moderate breeding success for most species. Common Murres have been around the two colonies for months by now, yet occupation of nesting sites has so far only been sporadic. I’ve yet again been observing frequent disturbances by up to four bald eagles at a time, which has prevented the murres from regularly settling into the colony and their nest sites (Figure 1). Because of the frequent eagle activity, I’ve rarely had the opportunity to see murres fully occupy all the Yaquina Head subcolonies; my best guess, however, is that the number of murres attending the colony is lower than at this time last year.

Despite regular disturbances, I observed the first few murre eggs at Yaquina Head on June 6th! While these eggs were predated within a few days, this does indicate that murres are willing to attempt breeding and I suspect more eggs will be seen soon. The ability of murres to breed successfully last year, despite heavy eagle disturbance early on, gives me reason to be cautiously hopeful that at least some Yaquina Head murres will manage to fledge chicks this year. Eagle disturbances appears to be fewer and less severe at Pirate Cove, and I’m eager to see how long the first few murre eggs at that colony persist. Despite the challenges imposed by eagles, murres appear motivated to attempt breeding.

Figure 1. One of several subadult Bald Eagles frequently seen disturbing the seabirds breeding at Yaquina Head, Oregon.

In contrast, Pelagic Cormorants are by and large not attending either the Yaquina Head or Pirate Cove colonies this year. Last summer saw record-high Pelagic Cormorant productivity and each monitored nest fledged an average of 2.8 chicks; however, so far this summer, I’ve only been able to locate a single nest with eggs across our two sites.

Cormorants, generally – and Pelagics, in particular – are known for highly variable reproductive outputs (Figure 2). Some seabirds (e.g., tubenoses) take more of a “low and slow” approach to reproduction that leads to a moderate but fairly consistent output across years, but Pelagic Cormorant reproduction is typified by highly variable, “boom or bust” cycles. Ainley and Boekelheide note in their Seabirds of the Farallon Islands (1990) that Pelagic Cormorants experience the most extreme interannual variation in breeding effort and success of all the seabird species that breed there. Cormorants are sensitive to fluctuations in prey populations and may skip breeding when prey is scarce, but they can also lay large clutches to take advantage of highly favorable conditions.

While 2023 was undoubtedly a “boom” year, 2024 is shaping up to be the accompanying “bust”. Initial monitoring of many well-built nests saw birds abandon nest-guarding early on and relatively few Pelagic Cormorants even appear to be attending the colony. Cormorant reproduction in the California Current System is related to sea surface temperature, with low reproductive effort often associated with warm-water, El Niño periods (Schmidt et al. 2015) like we experienced this last winter.

Figure 2. Pelagic Cormorant productivity at Yaquina Head from 2008-2023. Reproductive output from this species is highly variable between years.

Brandt’s Cormorants (Figure 3), on the other hand, are attempting to breed this year at both sites. Most are busily incubating three or even four egg clutches now, with the first chicks expected by the end of June. It’s possible that Brandt’s Cormorants finished the winter in better body condition than Pelagics, perhaps because they often exploit different foraging habitats and prey types (Ainley et al. 1981). Brandt’s Cormorant reproduction does tend to be somewhat less variable than that of their cliff-dwelling relatives (Ainley & Boekelheide 1990), but still varies considerably between years in relation to ocean conditions and prey abundance (Schmidt et al. 2015; Ainley et al. 2018). It’s interesting to observe these two congeneric species of seabird respond so differently to these conditions. However, cormorants may also abandon breeding efforts mid-season if prey availability should suddenly decline, so I’ll continue monitoring to see how the Brandt’s manage to do this summer.

Figure 3. Brandt’s Cormorant males spend lots of time collecting nesting material. Breeding Brandt’s were frequently seen collecting grasses from the headland at Yaquina Head, as well as stealing material from their neighbors’ nests.

As for other species, Western Gulls have been faithfully incubating their two and three egg clutches at both sites for several weeks now – it’s just a matter of time before our first downy chicks of the year are around. The Black Oystercatchers aren’t nesting at easily-visible sites this year, but their raucous calls continue to be a near-constant presence at both colonies. Excitingly, I’ve also observed Tufted Puffins circling the Yaquina Head murre colony on several occasions, and once saw one flying over Pirate Cove! While neither site has much suitable nesting habitat for puffins, the USFWS recently placed puffin decoys and artificial burrows on Gull Rock (located squarely between the Yaquina Head and Pirate Cove colonies) to draw them there. The puffins’ continued interest in these sites continues to raise my hopes that one day soon we’ll have Tufted Puffins nesting again on the Central Coast. 

So far, it seems challenging to predict just what kind of year we’ll see on the Oregon Coast. Reduced breeding effort by Pelagic Cormorants and (to a lesser extent) murres, suggests unfavorable conditions. Yet, murres (though perhaps in somewhat lesser numbers) have begun to lay eggs at both sites and Brandt’s are attempting to breed in seemingly typical numbers. I’ll continue to brave the wind and fog to document how this annual drama plays out.

References

Ainley & Boekelheide. 1990. Seabirds of the Farallon Islands: Ecology, Structure, and Dynamics of an Upwelling System Community. Stanford University Press, Stanford, CA, USA.

Ainley et al. 1981. Feeding ecology of marine cormorants in southwestern North America. The Condor 83: 130-131. https://doi.org/10.2307/1367418

Ainley et al. 2018. Ecosystem-based management affecting Brandt’s Cormorant resources and populations in the central California Current region. Biological Conservation 217: 407-418. https://doi.org/10.1016/j.biocon.2017.11.021

Schmidt et al. 2015. Shifting effects of ocean conditions on survival and breeding probability of a long-lived seabird. PloS ONE 10(7): e0132372. https://doi.org/10.1371/journal.pone.0132372

Posted on

Yaquina Head Monitoring Update: the end of the 2023 season

As we’re enjoying the first major rains of the fall here on the Oregon Coast, we now have another year of Yaquina Head seabird monitoring in the books (and the latest one to date)!  We wrapped up our Yaquina Head field season on the morning of September 6th after the fledging or loss of the last murre chicks remaining in our plots. 

For the seabirds as a whole, it was certainly an odd year, but not necessarily a bad one. After a poor 2022 season, the pelagic and Brandt’s cormorants did very well at Yaquina Head, with most nests fledging multiple chicks. In contrast, initial prospects for successful murre reproduction seemed poor.  The eagles and attending secondary predators hammered the murres early on:  we documented nearly 22 hours of eagle-related disturbances, witnessing a minimum of six murre adults and 73 eggs consumed during this time.  Considering that we only monitored the Yaquina Head colony three mornings a week, the total number of eggs predated must have been exponentially higher.

Almost without warning, however, the eagles moved on and the persistent murres were ready to exploit this reprieve.  As mentioned in our last update (emailed 08/23/23), this summer we recorded the latest median murre hatch date since monitoring began at Yaquina Head.  One consequence of this is that by the time the eagles moved on, and eggs began to persist for longer than a day or two, most murres had already attempted to breed. It’s not likely that some murres even re-laid eggs, only to lose their egg to the gulls a second time!  Reproduction is costly for murres and by the time conditions were good, most individuals had already given up and decided to save their finite energy resources for overwinter survival and (hopefully) next year’s nesting attempt.

Unfortunately, we don’t have multiple, complete colony counts documenting the decline in breeding murre numbers throughout the season, but we can use photographs to get a rough, qualitative understanding of this decline in colony size.  Compare these photos:  both were taken during the middle of chick-rearing, one showing the “full” colony (circa 2017), while the other is from early August 2023.  By mid-summer, the number of murres raising chicks on Colony Rock this year was clearly just a fraction of what we once observed.

Two photos (2017 and 2023) show the disparity in numbers of breeding murres at Colony Rock. Although some murres may have migrated to other colonies (e.g., Pirate’s Cove) in recent years, we believe the main driver leading to a small mid summer colony size was heavy predation pressure leading to early nest loss.

It isn’t all doom and gloom, however.  Those murres that laid or re-laid eggs exceptionally late did have a reasonable chance of successfully incubating that egg until it hatched.  For example, only 1 out of 3 eggs laid during June survived the marauding eagles, gulls, and crows to successfully hatch.  In contrast, more than 2/3 of the eggs laid during July ended up hatching.  Once out of the egg, those chicks that did hatch this year did quite well.  By the time chicks hatched in late July/early August, the eagles had left the colony alone, and more than 80%* of all hatched chicks survived to fledge.

In sum, although the overall colony size was substantially smaller, and murre egg losses were high until late June, the Yaquina Head colony was able to successfully raise some chicks this year.

Part of this success is surely attributable to this summer’s favorable ocean conditions and prey resources.  Our team documented what murre chicks were feeding on by photographing adult murres bringing fish to the colony, and we also recorded the frequency with which these feeds occurred during three, all-day provisioning watches.  We observed murres feeding their chicks an average of 3-4 times per day, bringing in lots of smelt (Family Osmeridae), plus lesser numbers of herring or sardine (Family Clupeidae) and sandlance (Family Ammodytidae).  These are all relatively nutritious prey items that enabled the surviving murre chicks to grow quickly and to eventually head to sea with their fathers by the beginning of September.

Many (~80%) of the murres that managed to hatch chicks were able to find enough fish to
successfully raise their chick until fledging.

2023 was certainly a roller coaster for the Yaquina Head murres, but the birds displayed incredible persistence.  We witnessed heavy predation pressure early on that threatened to lead to another year of complete reproductive failure (like 2022), but the murres displayed great flexibility and managed to lay eggs and raise chicks later than we’ve ever before documented.  In spite of all the diverse challenges seabirds face worldwide, their remarkable adaptability continues to give us hope.

Thank you all for the support and continued interest in the Yaquina Head Seabird Monitoring Program.  A huge thanks to our hard-working interns this year (Jacque, Neci, and Ricardo) and all the other people who made this work possible.  We hope to see you all out at the lighthouse next May!

*please note that exact values may change slightly pending further data proofing and processing

Posted on

Yaquina Head Seabird Monitoring: Mid-Summer 2023

Hello Everybody!

My name is Ricardo Rodriguez, I am the Education and Outreach intern at Yaquina Head Outstanding Natural Area through Environment for the Americas. I recently graduated from the University of California, Merced with a Bachelor’s degree in Biological Sciences. I am assisting Oregon State University’s Seabird Oceanography Lab’s research efforts to monitor the reproductive success of the Common Murres (Uria aalge), Brandt’s Cormorants (Urile penicillatus), and Pelagic Cormorants (Urile pelagicus). I have experience conducting avian point count surveys of urban songbirds in Northeast Los Angeles as a Community Climate Action Corps Fellow, but this my first taste of bird monitoring and nest tracking in my early career. I am very grateful for this opportunity to contribute to this long-term monitoring effort.

Per usual, the Common Murres have had a rocky season on Colony Rock. There were many eggs that were eaten or dropped by Western Gulls (Larus occidentalis) when the voracious Bald Eagles (Haliaeetus leucocephalus) would hunt for Murres. It has been very unfortunate seeing broken Murre eggs along Yaquina Head. Between the first monitored murre egg (June 12th) and our last recorded eagle disturbance (July 17th), we recorded more than 1.1 eagle disturbances per hour of observation and directly witnessed 73 eggs consumed by eagles and gulls during these events.  Eagle disturbances and predation of the Murres has have slowed down significantly since the middle of July, thankfully, thus allowing Murres to incubate any eggs that have not been destroyed .

Following disturbances from Bald Eagles, Western Gulls swoop in to feast on unprotected murre eggs. Photo credit: Ricardo Rodriguez.

Both adults of a Common Murre breeding pair incubate the egg. The incubation period can take anywhere from 28 to 37 days.  The first Murre chick was observed on July 19, 2023 on Seal Rock and this year is likely the latest median hatch date we’ve ever recorded (peak hatch this year was between July 28th and August 7th).  2018 was the previous record for latest median hatch date (~July 15th) at Yaquina Head, so the delay caused by predator disturbance this year was quite significant. As many as 26 Murre chicks have been recorded in our monitoring plots at Colony Rock alone, and we are hopeful to see many more on the other offshore islands that we have been observing.

Better late than never! Median hatch date for murre chicks is the latest we’ve ever recorded at Yaquina Head. Photo credit: Will Kennerley.

Adult Murres have been observed and photographed to bring their chicks lots of Smelt (Osmeridae) and Herring (Clupeidae ). We’ve also conducted our first of multiple dawn-to-dusk provisioning watches by which we estimate the rate at which adult murres provision their chicks.  We hope to fit in two more of these watches before weekly until more chicks fledge.  Some chicks have already fledged and their calls can sometimes be heard from the headland.  I have worked at Yaquina Head since the beginning of April; I have clearly seen less and less Murres attending the colony compared to the amount back in May.

Oregon State University PhD student Suzanne Winquist records a murre feeding its chick during one of our dawn to dusk provisioning watches. Photo credit: Will Kennerley.

We are nearing the end of our Pelagic and Brandt’s Cormorant monitoring efforts at Yaquina Head Following a total of 55 nests across the two species, we estimated that Pelagic and Brandt’s Cormorants fledged an average of 2.8 and 2.4 chicks per nest, respectively.  All in all, we estimated that more than 80% of all cormorant chicks that hatched eventually went on to fledge, among the highest we’ve recorded in the 16 years we’ve been monitoring cormorant productivity.  

It has been an absolute pleasure working with an amazing team of researchers.  Come visit us out at Yaquina Head!

— Ricky, Neci, Jacque, Mariam, and Will

Posted on

Yaquina Head Seabird Monitoring: 2023 Early Season Update

By Will Kennerley, Faculty Research Assistant

It’s once again summer on the Oregon Coast and that means the seabirds are back at Yaquina Head.  My name is Will Kennerley and I’m the newest faculty research assistant in the Seabird Oceanography Lab. Part of my work will include leading the monitoring fieldwork at Yaquina Head this year.  I spent the previous six summers working with seabirds in the Gulf of Maine, including two seasons of fieldwork for my Master’s, which I completed here at OSU in May.  I’m looking forward to applying this experience to Oregon’s large and diverse seabird populations.

Monitoring work at Yaquina Head began towards the end of May with the confirmation that Brandt’s and Pelagic Cormorants were both breeding here this year.  Pelagic Cormorants failed to breed successfully in 2022, so we were anxious to see how they would perform.  Much to our relief, at least 70 Pelagic Cormorant nests have been documented in Smuggler’s Cove, alone, and most have healthy clutches of four eggs. 

Our very first Pelagic Cormorant chick was observed on June 23rd and we’re hopeful that there will soon be many more!  As for Brandt’s Cormorants, we recorded our first chick back on June 16th and most Brandt’s nests so far have at least one hatched chick, with even more on the way!  It seems that the cormorants are off to a good start this year.

Most Pelagic Cormorants remain on eggs at the Smuggler’s Cove subcolony at Yaquina Head.  The first chicks for this species were noted in late June and many Pelagic Cormorant chicks will likely be hatching out over the next week.

In typical fashion, the situation for the Common Murres is a little less rosy.  Starting in the middle of June, murre eggs appeared in a slow trickle that was easily consumed by Western Gulls during the frequent eagle disturbances.  There were a couple troubling weeks in which our monitoring team would observe new nests in our monitoring plots during each visit without any of these eggs ever surviving until the following check, just two or three days later. 

This situation has improved somewhat during the last week, thankfully, and eggs are being laid in greater numbers; hopefully this bump in egg-laying can overwhelm the marauding gulls and allow some eggs to survive and develop.  Overall, I suspect murre productivity will be poor at Colony Rock, where I’ve seen as many six different Bald Eagles roosting at a time, but some of the smaller rocks around Yaquina Head provide better cover for the murres and have thus far avoided most of the disturbances and depredation.  Although the season is advancing rapidly, there’s still some time for murres to be at least somewhat successful – I’m not ready to be pessimistic just yet! If the murres do succeed in hatching some chicks, this year’s median chick hatch date will likely be the latest ever recorded at Yaquina Head.

The complex topography of “Stegosaurus” and the other smaller subcolonies at Yaquina Head may provide sufficient cover from aerial predators for at least a small number of murres to breed successfully.

This year we are also systematically monitoring breeding murres and cormorants at Pirate Cove in the town of Depoe Bay.  We’re employing the same protocols as at Yaquina Head, just with slightly less frequent visits.  While the situation at these two colonies is broadly similar, we’ve documented fewer eagle disturbances per hour of observation at Pirate Cove than at Yaquina Head so far.  Because of this, a small number of murre eggs have now been incubated for at least two weeks and I am hoping that murres at this colony will successfully produce at least a few chicks.

Also of note this year is the consistent Tufted Puffin sightings that we’ve had at Yaquina Head!  As many as three individuals have been observed at once, and we’ve seen the birds circle the murre colony numerous times over the course of some mornings.  One Tufted Puffin even landed on the backside of Colony Rock, where puffins once bred.  While there haven’t been any signs of a nesting attempt, our hopes are high for continued puffin activity throughout this season and next.

If you’re around at Yaquina Head in the mornings, come introduce yourself!  I’m typically joined by a great team comprised of Jacque (REU intern), Neci (Doris Duke scholar), and Ricardo (Environment for the Americas BLM/YHONA intern) and we’d be happy to say hello.

A Bald Eagle seizes an adult Common Murre at Pirate Cove.  This disturbance caused the rest of the colony to flee, leaving the eggs vulnerable to predation by Western Gulls (note the gull with its mouth full, just to the right of the eagle).
Posted on

Yaquina Head Seabird Monitoring: July 2022 Update

By Yaya Callahan, NSF REU INTERN

Hello everyone!

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. 

A subadult bald eagle attacking a murre adult on Colony Rock.
Photo: Sofia Franco Cruz

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. 

The rocks at Yaquina Head, Oregon.

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. 

See you again for our next update in August!

Brandt’s cormorants feeding a chick on South Headland (July 8th). Photo: Yaya Callahan
Posted on

Yaquina Head Seabird Monitoring: July 2021 Update

By, Laney Klunis, NSF REU Intern

Hello everyone!

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.

Main colony rock at Yaquina Head Outstanding Natural Area, Newport, Oregon

Eagle Disturbances

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.

Cormorants

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.

NSF REU Intern, Laney Klunis monitoring at Yaquina Head on a foggy morning. 
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!