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.
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.
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
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 .
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.
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.
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!
By Alastair Baylis, South Atlantic Environmental Research Institute
A globally significant wildlife wonder spot
The Falkland Islands, located on the southeast Patagonian Shelf, are a self-governing UK Overseas Territory (UKOT), and a globally significant wildlife wonder spot. Home to 75% of the global population of Black-browed albatross, 50% of the global population of South American fur seals, 30% of the global population of Rockhopper and Gentoo penguins, to list but a few. This means that population trends of Falklands seals and seabirds disproportionately influence the global population trends and conservation status of these species.
Marine Managed Areas & IUCN Key Biodiversity Areas
In recognition of the importance of the Falkland Islands environment to both wildlife and the community, and striving toward holistic marine management, the Falkland Islands Government started a process of Marine Spatial Planning. This included identifying marine areas for enhanced protection as Marine Managed Areas (MMAs)– a broad term that includes Marine Protected Areas (Esch 2006). MMAs focussed on marine wilderness areas – areas that have irreplaceable biodiversity and are near-pristine due to low fishing impact, but presently do not have a legal framework for protection. Through stakeholder engagement, several areas were chosen as proposed MMAs. These areas included seaward extensions of globally important breeding colonies of seabirds and seals where animals are known to congregate (Granadeiro et al. 2008).
To inform the Falkland Islands MMA process, we identified important at-sea areas for seals and seabirds to understand how these predators use the proposed MMAs. One overarching aim of our paper was to place the conservation value of the proposed MMAs into a global context. Hence, we also identified IUCN Key Biodiversity Areas (KBAs) – (marine) areas that “contribute significantly to the persistence of global biodiversity”, which are a widely adopted approach to help inform systematic conservation planning, and compared these to proposed MMAs.
Our KBA journey
Much of this blog is focussed on our KBA journey, which is one component of the paper. In-part, because using tracking and survey data to identify KBAs are of particular interest locally. But, in general, we found limited discussion regarding challenges. This is perhaps, a good point to emphasize the distinction we make throughout the paper and again here, between the KBA concept (which we do not critique), versus methods used to identify polygons to assess against KBA criteria.
Looking out over the Jason Islands. Photo: R. Orben
Briefly, our methods went something like this – we collated tracking data (1999-2019) and used a several approaches to identify areas for assessment against KBA criteria (for those wanting the details, a combination of kernel density estimation methods originally designed to identify Important Bird and Biodiversity Areas (IBAs) and model-based predictions).
Here is what we found:
1. The Patagonian Shelf is vast and vastly important for marine predators.
It should come as no surprise that much of the Patagonian Shelf around the Falkland Islands is important (see also Augé et al. 2018, Baylis et al. 2019). In fact, depending on the methods used, over 70% of the Falkland Islands EEZ could qualify as a KBA. This is because the Falklands are home to numerous and globally significant populations of seals and seabirds – many species of which breed almost ubiquitously around the Falklands. We will touch briefly on how this could influence management later in this piece (see point 4). In terms of overlap with proposed MMAs, depending on methods used, up to 45 % of KBAs were overlapped with proposed MMAs. But this comparison and indeed the significance of findings, are a little clouded by caveats associated with methods (see point 2 and 3).
2. Threshold-based criteria of KBAs are standardized, repeatable, and globally applicable – which is worth celebrating. For tracking data, the methods used to identify areas to assess against KBA criteria are not standardized.
Given KBAs might be considered for potential protected areas, it would be useful to understand and quantify uncertainty in areas selected to be assessed against KBA criteria. This is because as scientists, we want to provide decision makers with reliable data and robust science narrative, which ensure the areas identified as important are well supported.
A couple of challenges that we encountered when following popular methods, are as follows. Firstly, common to all tracking datasets, tracking data were inevitably imperfect and biased by tracking effort. This isn’t a deal breaker, but our potential KBAs reflected colonies from which seals and seabirds were tracked from, but not necessarily where they occur. For example, tracking data from one colony, might not represent important areas for other colonies.
A second widely recognized challenge is that current methods based on kernel density estimation are sensitive to often arbitrarily selected values. Indeed, areas identified for KBA assessment can vary by thousands of km, depending on model values selected. Ideally, with a bit of common sense and knowledge of species biology, you can make some informed decisions about what values are sensible to use, but it isn’t always clear, and this can create uncertainty in which areas are most appropriate to assess against KBA criteria. One approach to address these limitations was to use models to predict the distribution of animals from all colonies around the Falklands. But then the entire Patagonian Shelf around the Falklands is potentially a KBA (point 1).
3. IUCN KBA guidelines continue to be refined and updated.
Too right! It is important that the guidelines continue to evolve to ensure KBA guidelines are applied rigorously. The most recent guidelines (IUCN 2020) clarify that species must predictably aggregate at a site to trigger KBA criterion D1a (just one of several criteria, but the one we felt best suited our data). However, predictability is scale dependent and we don’t yet know how this definition will apply to tracking data for wide-ranging marine predators that forage on patchily distributed prey. Hence, a range of challenges exist with current methods and the motivation for highlighting these challenges are to stimulate discussion on how we can continue to improve methods that better serve the globally standardized KBA criteria.
4. Fixed boundary approach to marine conservation (MMAs, KBAs etc).
Moving away from challenges associated with methods, it is clear that the proposed Falkland Islands MMAs are imperfect in the context of encompassing the entire foraging ranges of wide-ranging marine predators. So where does this leave species that forage across vast areas of the ocean, and for which KBAs might also encompass vast marine areas? It might be that a fixed area approach to management may not be feasible or the most effective way to manage and conserve species, and we should look to combine fixed area management with other approaches.
The good news is that, in addition to existing large-scale regulations that are not area-specific (e.g., bycatch mitigation), other innovative options exist, which could potentially be used in combination with MMAs. For example, Dynamic ocean management, could achieve similar protection to fixed-boundary spatial management in a smaller area, as it tracks the temporal shifts in the distribution of species and their threats, rather than having to encompass the entire temporal variability in a species range, within a fixed area (Maxwell et al. 2015). For some examples of this implemented in the USA check out TurtleWatch, WhaleWatch, and EcoCast.
Falkland Islands proposed MMAs
Despite limitations there is much to celebrate. The Falkland Islands proposed MMAs are an incredibly exciting development for marine management and conservation in the South Atlantic. The proposed MMAs include much of the Falkland Islands kelp forests, which play an important role in nutrient cycling, carbon sequestration and are crucial to larval life history phases of squid and fish, important to both fisheries and higher marine predators. They protect near-pristine benthic habitats and encompass the foraging ranges of many marine predators, while benefiting others by providing a buffer around breeding colonies.
In total, these areas would protect about 15% of the Falkland Islands Conservation Zones (i.e., Exclusive Economic Zone), allowing the Falkland Islands to make great strides towards contributing to the 2010 Aichi Biodiversity Target of 10% ocean protection (and the proposed 2030 Target of 30%).
The proposed MMAs, if designated, would also establish the policy and legislative framework for marine protection, which will pave the way for any future designations, facilitate the management and conservation of globally significant populations of marine predators, and usher in a new era of ecosystem-based management. However, there is more work to be done to support and refine this process. We are currently exploring how innovative methods, such dynamic ocean management, could compliment fixed area management to help conserve wide-ranging marine predators at relevant spatial scales.
To access our paper please follow the link below:
Baylis, A.M.M., de Lecea, A.M., Tierney, M., Orben, R.A., Ratcliffe, N., Wakefield, E., Catry, P., Campioni, L., Costa, M., Boersma, P.D., Galimberti, F., Granadeiro, J.P., Masello, J.F., Pütz, K., Quillfeldt, P., Rebstock, G.A., Sanvito, S., Staniland, I.J. and Brickle, P. (2021), Overlap between marine predators and proposed Marine Managed Areas on the Patagonian Shelf. Ecological Applications. Accepted Author Manuscript e02426. https://doi.org/10.1002/eap.2426
This research was funded by the UK Government through The Darwin Initiative, The Falkland Islands Government, & the Winifred Violet Scott Estate Trust.
Augé, A., M. P. Dias, B. Lascelles, A. M. M. Baylis, A. Black, P. D. Boersma, P. Catry, S. Crofts, F. Galimberti, J. P. Granadeiro, A. Hedd, K. Ludynia, J. F. Masello, W. Montevecchi, R. A. Phillips, K. Pütz, P. Quillfeldt, G. A. Rebstock, S. Sanvito, I. J. Staniland, A. Stanworth, D. Thompson, M. Tierney, P. N. Trathan, and J. P. Croxall. 2018. Framework for mapping key areas for marine megafauna to inform Marine Spatial Planning: The Falkland Islands case study. Marine Policy 92:61–72.
Baylis, A. M. M., M. Tierney, R. A. Orben, V. Warwick-Evans, E. Wakefield, W. J. Grecian, P. Trathan, R. Reisinger, N. Ratcliffe, J. Croxall, L. Campioni, P. Catry, S. Crofts, P. D. Boersma, F. Galimberti, J. Granadeiro, J. Handley, S. Hayes, A. Hedd, J. F. Masello, W. A. Montevecchi, K. Pütz, P. Quillfeldt, G. A. Rebstock, S. Sanvito, I. J. Staniland, and P. Brickle. 2019. Important At-Sea Areas of Colonial Breeding Marine Predators on the Southern Patagonian Shelf. Scientific Reports 9:1–13.
Esch, G. . (Ed). 2006. Marine Managed Areas : Best Practices for Boundary Making. NOAA Coastal Services Cente.
Granadeiro, J. P., L. Campioni, and P. Catry. 2018. Short Communication Albatrosses bathe before departing on a foraging trip : implications for risk assessments and marine spatial planning: Bird Conservation International, 28:208–215.
IUCN. 2020. Guidelines for using A Global Standard for the Identification of Key Biodiversity Areas. Version 1.1. Prepared by the KBA Standards and Appeals Committee of the IUCN Species Survival Commission pp.220.
Maxwell, S. M., E. L. Hazen, R. L. Lewison, D. C. Dunn, H. Bailey, S. J. Bograd, D. K. Briscoe, S. Fossette, A. J. Hobday, M. Bennett, S. Benson, M. R. Caldwell, D. P. Costa, H. Dewar, T. Eguchi, L. Hazen, S. Kohin, T. Sippel, and L. B. Crowder. 2015. Dynamic ocean management: Defining and conceptualizing real-time management of the ocean. Marine Policy 58:42–50.