3. Nest sites and habitat characteristics for Red-tailed Tropicbirds (Phaethon rubricauda) and White-tailed Tropicbirds (P. lepturus) at Kīlauea Point National Wildlife Refuge, Kauaʻi, in 2019
Dates
Publication Date
2020-12-08
Start Date
2019-04-08
End Date
2019-07-07
Citation
Felis, J.J., Kelsey, E.C., Adams, J., Stenske, J.G., and White, L.M., 2020, Population estimates for selected breeding seabirds at Kīlauea Point National Wildlife Refuge, Kauaʻi, in 2019: U.S. Geological Survey data release, https://doi.org/10.5066/P93MPDR1.
Summary
During 8-11 April, 13-18 May, and 1-7 July 2019, we censused Red-tailed Tropicbird (Phaethon rubricauda) and White-tailed Tropicbird (P. lepturus) nests in Kīlauea Point National Wildlife Refuge (KPNWR), Kauaʻi, by searching all foot-accessible areas and by searching all cliffs and islets with spotting scopes from remote vantage points. We censused over the course of three visits to account for prolonged and asynchronous nesting. For ground searching, we used previous nest census results, recommendations from the previous Refuge biologist, and knowledge of tropicbird nesting habitat, to focus searches in areas where nesting was likely: along cliff edges and steep slopes, particularly at the base of ironwood trees (Casuarina equisetifolia) [...]
Summary
During 8-11 April, 13-18 May, and 1-7 July 2019, we censused Red-tailed Tropicbird (Phaethon rubricauda) and White-tailed Tropicbird (P. lepturus) nests in Kīlauea Point National Wildlife Refuge (KPNWR), Kauaʻi, by searching all foot-accessible areas and by searching all cliffs and islets with spotting scopes from remote vantage points. We censused over the course of three visits to account for prolonged and asynchronous nesting. For ground searching, we used previous nest census results, recommendations from the previous Refuge biologist, and knowledge of tropicbird nesting habitat, to focus searches in areas where nesting was likely: along cliff edges and steep slopes, particularly at the base of ironwood trees (Casuarina equisetifolia) and beneath dense shrubs. Within these habitats, we searched the ground as thoroughly as vegetation and topography would permit. In areas that we did not expect to be suitable tropicbird nesting habitat (e.g. flat, open areas far from cliff edges or windward slopes), we scanned the area but did not search as thoroughly as in suspected nesting habitat.
For ground-accessible nests, we assigned a nest number, recorded the GPS location, flagged the nest, and recorded nest contents and habitat type. For inaccessible nest habitat, we used a spotting scope to view remote cliffs and offshore islets for tropicbird nests. For remote sites, we identified tropicbirds to species, recorded the location using a georeferenced satellite image, collected reference photographs for subsequent checks, and recorded habitat type when possible. In May and July, we used locations of nests from previous visits (and reference photographs for remotely viewed sites) to record tropicbird presence at previously identified nest sites and also to assist with searches for newly initiated nests. In July, our last visit, we removed flags after checking previously located nests and recorded, but did not flag, newly initiated nests. On each visit, we classified nest contents and estimated chick age (if present). We also recorded three metrics of nest habitat: the landform the nest was on, the structure of the nest site (e.g., what provides some shade), and the first and second most dominant plant types.
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TropicbirdNests.xml Original FGDC Metadata
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TropicbirdNests.csv
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Purpose
These data were collected to determine the population size of Red-tailed Tropicbirds (Phaethon rubricauda) and White-tailed Tropicbirds (P. lepturus) breeding at Kīlauea Point National Wildlife Refuge, Kauaʻi, in 2019.
