Loon occupancy dynamics in Western Arctic Parklands, Alaska, 2011–2018
Mizel JD, Flamme MJ, Schmidt JH. 2021. Loon occupancy dynamics in Western Arctic Parklands, Alaska, 2011–2018. Natural Resource Report. NPS/ARCN/NRR—2021/2280. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/nrr-2286711
We investigated lake occupancy dynamics for Yellow-billed (Gavia adamsii), Pacific (Gavia pacifica), and Red-throated Loons (Gavia stellata) in Western Arctic National Parklands (WEAR) and assessed habitat predictors of occupancy for all three species using aerial survey data from 2011–2018. Annual estimates for the number of lakes occupied by Red-throated Loon ranged from 841.45–957.99 from 2016–2018. Breeding probability was apparently stable for Yellow-billed and Pacific Loon from 2011–2018. Lake area was a strong positive predictor of Yellow-billed Loon breeding probability, while both lake area and connectivity (the presence or absence of a connecting stream) were strong positive predictors of Pacific Loon breeding probability. Red-throated Loon occupancy probability declined with lake area and increased with proximity to the coastline and with shoreline complexity. We found that the probability of a lake persisting in the breeding or occupied state from one year to another was relatively high for all three loon species, suggesting that nesting habitat in the study area is likely nearly saturated by their combined populations. In addition, breeding density across the loon assemblage appears to be higher in near-coastal areas and in the area surrounding Shishmaref Lagoon.
- Type
- Published Report
- Authors
- Mizel, Jeremy; Flamme, Melanie; Schmidt, Joshua
- Date of Issue
- 2021-07
- Publisher
- National Park Service
- DOI
- 10.36967/nrr-2286711
- Units
- ARCN , NRSS , WEAR
- Keywords
- Bering Land Bridge National Preserve, Birds, Cape Krusenstern National Monument, Pacific Loon, Red-throated Loon, Yellow-billed Loon
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Birds