Breeding Bird Monitoring at Isle Royale National Park, Michigan: 1996-2008

Egan, Alexander

Standardized, unlimited distance point counts were conducted on established trails at Isle Royale National Park from 1996 to 2008. Eight routes, with a total of 130 points, spanned the island. Species used in data analyses were those appropriately sampled by point count methods in forested terrain. An average of 1,424 individuals representing 57 species was detected annually. Eighty-five species from twenty-five families were identified during the 13-year period. In order to track changes in abundance over time, linear regression analyses were reported for most species that were detected. Significant increases were found for ten species: pileated woodpecker, golden-crowned kinglet, brown creeper, song sparrow, hairy woodpecker, hermit thrush, Wilson’s snipe, yellow-bellied flycatcher, alder flycatcher, and red-breasted nuthatch. Significant declines were found for eight species: Cape May warbler, evening grosbeak, least flycatcher, rose-breasted grosbeak, chipping sparrow, Tennessee warbler, common raven, and Canada warbler. Isle Royale trends were compared to regional analyses by state, regional forest ecosystem, and regional national forests. Results were generally consistent with other studies. Findings from annual park reports, including diversity measurements for each route and comparison of species richness detected on point counts with a recent, five-year breeding bird atlas are discussed. These results demonstrate that the Isle Royale bird survey is a useful tool that park managers can utilize for identifying species of concern on the island, while both the public and regional land managers can benefit from the general information revealed on this widely valued group of vertebrates.

Breeding Bird Monitoring at Isle Royale National Park, Michigan: 1996-2008

Series

Collections