Research

To obtain code for completed projects, please look for us on GitHub. 

Current Projects

Seabird populations at Channel Islands National Park 

Funding: Channel Islands National Park

CollaboratorsCalifornia Institute of Environmental Studies, Montrose Settlements Restoration Program, U.S. Geological Survey Western Ecological Research Center – Santa Cruz Field Station

Contact: Amelia J. DuVall

Image: Andrew Yamagiwa

Channel Islands National Park provides essential habitat for marine avifauna, including vital nesting and feeding grounds for 99% of the seabirds in southern California and important breeding areas, wintering areas, and migratory stopovers for shorebirds. At least fourteen seabirds and shorebirds use the islands for essential breeding grounds and an additional three are suspected to have bred there historically. There is no current information on the baseline status and trends in demographic parameters and population abundance for several key avifauna at the park. These taxa are being impacted by existing stressors (e.g., disturbance via light pollution and increased park visitation, depredation, loss of nesting habitat) and could be significantly affected by future stressors (e.g., offshore wind energy development, changes in prey distribution and habitat due to climate change). This project fills a critical knowledge gap on the population trends for eight priority taxa identified by Channel Islands National Park for the seabird monitoring program. We are analyzing long-term monitoring data to provide estimates of relative abundance and reproductive success over time as a function of environmental conditions such as sea surface temperature and forage fish abundance. This information will be used to conduct in-depth program reviews to refine the seabird monitoring program and prioritize management and conservation actions.

Seabird ecology and conservation at Tetiaora, French Polynesia 

Funding: Private Funders

Collaborators: Dr. Beth Gardner and Dr. Julia Parrish (University of Washington), Tetiaroa Society

Contact: Amelia J. DuVall or Eve Hallock

Image: Amelia J. DuVall

Seabirds are one of the most endangered groups of birds worldwide. The introduction of mammalian predators to breeding islands, by-catch in fishing vessels, and changing ocean conditions related to climate change all represent threats to seabirds. Tetiaroa, a private atoll in French Polynesia with a land area of only about 6 square kilometers, is home to tens of thousands of breeding seabirds of 10 different species. In this incredible natural laboratory, we are studying pre-rat eradication seabird communities ahead of a planned eradication of rats in 2020. Coupling these pre-eradication studies with post-eradication studies will allow us to better understand the effects of introduced predators and the benefits that may be derived from eradication. We are also initiating a long-term banding program at Tetiaroa in order to track individuals across their lifetimes to better understand the relationships between survival and ocean conditions. Our focal species at Tetiaroa include the red-footed booby (Sula sula), the brown booby (Sula leucogaster), the brown noddy (Anous stolidus), the sooty tern (Onychoprion fuscatus), and the greater crested tern (Thalasseus bergii). In 2020, we also plan to attach GPS tags to the largest of these species – the red-footed booby and the brown booby – to determine where these species forage both during and outside the breeding season.

Synchrony in seabird survival

Funding: Swedish Research Council

Collaborators: Swedish Museum of Natural History, Aarhus University, Norwegian Institute for Nature Research, Centre for Ecology & Hydrology

Contact: Sarah Converse

Image: Martina Kadin

Seabirds are excellent model systems to study spatiotemporal patterns of anthropogenic impact in marine systems. For example, consider the effects of storms occurring with higher frequency due to climate change. While the direct effects may be local or regional, the ecological impact may manifest on different scales if birds from multiple breeding colonies concentrate in one area when they are simultaneously affected by the weather event. A shared driver affecting several populations can be detected via synchronous variation in population numbers or demographic parameters. Such synchrony renders the metapopulation more vulnerable to extinction, as single events or sudden changes to environmental conditions may have catastrophic impacts across the species’ entire range. Synchrony also illustrates ecological connectedness, the scale at which threats influence populations or species. We are using hierarchical models to investigate synchrony in seabird survival and its impact on population trends in these long-lived species. We use two species which breed over large areas of the North Atlantic as our case studies: the common murre (Uria aalge) and the European shag (Phalacrocorax aristotelis). During the winter, the shag migrates a short distance while the murre disperses much more widely. This contrast allows us to get behavior-specific insights about seabird population response to environmental change, with an emphasis on interactions across scales.

Demography of pigeon guillemots in Puget Sound, Washington

Funding: National Science Foundation

Collaborators: Guillemot Research Group

Contact: Sarah Converse

Image: Ron LeValley

Pigeon guillemots (Cepphus columba) are one of only three alcids that nest in Puget Sound. Despite having been identified as an indicator species for the region, little research has been done on the demographics of Pacific coast populations. This project is a collaboration with the Guillemot Research Group, a citizen science data collection program that has been monitoring these birds during the breeding season since 2008 on Whidbey Island, WA. Pigeon guillemots nest in unobservable nests on cliff sides and chicks fledge at night, so the nest outcomes are uncertain. Thus, we use counts of adult birds delivering prey to nests as the foundation of an integrated population model built on a novel multi-event parameterization to estimate reproductive success. This project accounts for life history traits and features of the data collection protocol that complicate both the ecological and observation processes in order to examine trends in local abundance and reproduction. As an indicator species, pigeon guillemots are an important component of nearshore ecosystems throughout Puget Sound, likely affected by environmental variability (e.g., pollution, coastal development, and changes in the distribution and availability of local forage fish). This work highlights the importance of citizen science initiatives and will inform ongoing conservation, monitoring, and management efforts for this species, other seabirds, forage fish, and ecosystem resilience throughout the Puget Sound region.