2002 Breeding Bird Survey Report: Apostle Islands National Lakeshore

Kroll, Julie; Van Stappen, Julie

The Apostle Islands National Lakeshore breeding bird survey was established in 1990 to determine the status and trends of breeding birds in the lakeshore and in response to the growing need to document abundance trends of neotropical migrant birds in the United States. The significance of this project has continued to grow, such that the abundance trends of neotropical migrant birds are now recognized by the Lake Superior Binational Forum as an indicator of overall ecosystem health within the Lake Superior basin .The 2002 breeding bird survey was conducted from 7 June to 27 June. Ten minute point counts were conducted at 106 points distributed along ten transects. The 2002 survey marks the eighth year that data collection has occurred at permanently marked points. When comparing results from 1995-2002, data from 1998 was not included because all transects where not completed. A total of 1176 birds comprising 92 species were observed in 2002. The mean number of birds per survey point was 11. The highest number of birds per point (18) was found on Sand Island. The lowest number of birds per point occurred on Outer Island (9). The highest number of total birds was recorded on Sand Island (215), which has the highest number of points. The highest number of species(40) was recorded on Outer and Sand Island. Raspberry, Long and Devils Islands had the lowest number of species recorded(29). Species diversity for islands/mainland ranged from 1.23 (Oak Island) to 1.45 (Mainland), with a mean diversity of 1.28. Species diversity for habitat ranged from 0.93 (beaver flowage) to 1.38 (northern mixed hardwoods) with a mean diversity of 1.23. By habitat, the highest number of birds per point occurred in pine forest (13), followed by aspen/birch forest and old-growth conifer forest habitats (12). The total number of birds was highest in northern hemlock sugar maple forest (179), followed by pine forest (159) and boreal forest (150). The number of species by habitat was highest pine forest (37) followed by the northern mixed forest (36). Also in this year, fifteen of the most abundant species made up 68% of the total birds recorded. Nashville warblers, a special concern species that has been declining, had a sizeable increase from last year to this year. Of the four special concern species that the park has looked Nashville warblers have fluctuated the most in abundance and this years numbers where similar to 1997 and 1995. Sixty-eight percent of the total number of birds was in the top fifteen species. Of the fifteen most abundant species that were recorded Nashville warblers and Oven bird’s showed substantial increases this year. Numbers from 1995-2002 was the second highest this year and all transects had an increases in total number and species. Compared to the average from 1995-2001 Sand Island and Oak Island showed substantial increases. Also, habitats showed substantial increases in northern mixed forests and northern hemlock sugar maple habitats.