Black oystercatcher chick diet and provisioning: 2014 annual report
Stark SB, Robinson BR, Phillips LM. 2015. Black oystercatcher chick diet and provisioning: 2014 annual report. Natural Resource Data Series. NPS/KEFJ/NRDS—2015/749. Fort Collins, Colorado
Black oystercatchers are important members of intertidal community in Kenai Fjords National Park (KEFJ); they structure the nearshore marine environment through predation, are completely reliant on nearshore marine habitats for breeding and foraging, and are a visible bird species. For these reasons, black oystercatchers are vital signs for long-term monitoring at KEFJ. However, data collected during the first few years of monitoring raised questions about possible limitations of the monitoring protocol and identified gaps in breeding ecology knowledge. To address these questions, we conducted a collaborative two-year study, building on previous studies of black oystercatcher breeding productivity in Alaska. Our goal was to examine the role of intertidal invertebrates in the diet of black oystercatcher chicks to assess the influence of these prey items on their body condition and survival. In summer 2014, we conducted systematic boat-based surveys of historically known nesting sites in Aialik Bay, the Chiswell Islands and Northwestern Fjord to locate active black oystercatcher breeding territories. When territorial pairs were found, we searched the area to locate the nest and deployed a Reconyx digital infrared remote-camera near the nest. We monitored 25 nests throughout the breeding season, 60% of which hatched at least one chick. Once eggs hatched, we captured chicks every three days to determine growth rates and body condition and to collect blood plasma for stable isotope analysis of diet. We captured 30 individual chicks repeatedly for a total of 104 captures. We conducted observations of adults with chicks to determine the rate of provisioning and the type and size class of items provisioned. We observed adult black oystercatchers in 12 territories delivering a wide variety of invertebrate prey to their chicks. Of the chicks that hatched, 60% survived to fledge. Apparent nest success of black oystercatchers in this study was comparable to previous studies conducted in KEFJ. This was the second and final year of this study; analysis of data and samples collected will take place over the next year.
- Type
- Published Report
- Authors
- Stark, Sam; Robinson, Brian; Phillips, Laura
- Date of Issue
- 2015-01
- Units
- KEFJ , NRSS , SWAN
- Keywords
- Aialik Bay, Black oystercatcher, Chiswell Islands, Diet, Inventory, KEFJ, Kenai Fjords, Monitoring, National Park, Northwestern Fjord, provisioning, Vital Signs
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Birds