Steve Kupcho and his helpers have been conducting Breeding Bird Surveys (BBS) of the Riveredge State Natural Area #197 since 1987. This area includes the Riveredge Creek corridor and Vernal Pond. The inventory is done as part of the statewide breeding bird survey project administered by the DNR’s Bureau of Endangered Resources.
The purpose of the survey is to:
- supply basic inventory information on the species and numbers of birds present monitor breeding bird populations over the long term on natural areas which are now or are expected to be subjected to environmental stress,
- provide additional information on threatened and endangered species,
- aid the Natural Areas Preservation Council in evaluating specific natural areas as well as to identify additional natural areas which may be worthy of inclusion in the natural area system, and
- assess the impacts of management practices on the avian fauna
Cooperators are asked to use the following methods whenever possible.
- Keep within Natural Area boundaries on a route that’s easy enough to be repeated.
- Walk into the area at least 50 yd. (50 m) to avoid any edge effect before starting.
- Walk 5 minutes then stand 5 minutes recording all the birds seen or heard. Repeat this procedure until the survey route is completed.
- Try not to count any individual bird more than once.
- The distance covered should be 110-220 yd.
- The placement of transects is up to the observer; however, the same route should be followed from year to year.
- A number of walk/stand periods are included with survey results
The survey is done between June 1st & July 4th. The count begins one-half hour before sunrise and ends about four hours later. Dry days are preferred but a little drizzle or brief showers are acceptable as long as the wind is less than 12 mph.
All birds seen or heard that can be identified as to species are counted except for birds passing high overhead or hatchling birds. Species observed in the area during the breeding season but not on a survey are included along with the date they were seen. Species not on the form are added on the bottom. Estimates are only permissible for flocks too large to count one by one.
Summary of BBS Data at Riveredge from 1987-2009
Steve and his partners have encountered as few as 35 species and as many as 46 during this annual count. The number of individual birds has varied from 195 to 360 birds in a season. The most common species encountered among the 81 species identified during the survey include the song sparrow, house wren, gray catbird, northern cardinal, and common yellowthroat. Thirteen species have been sighted only once, and 17 species have been tallied every year during the 23 surveys. Population trends are evident. For example, population data of four “thrushes” (eastern bluebird, wood thrush, veery and American robin) when taken collectively shows a decline between the first and second half of the surveys. From 1987-1997, the average number of thrushes was 29.5, whereas the average number from 1998-2009 was only 17 individuals. Examination of data from the Wisconsin Breeding Bird Atlas reveals similar findings. According to the Atlas the veery is a species that has declined 2.2% per year in Wisconsin over the 41 period of 1966-2006.
Some of the rarest birds seen over the years include the red-headed woodpecker, sedge wren, pine warbler, cerulean warbler, yellow-throated vireo, warbling vireo and savannah sparrow. The data from the survey is insufficient to draw any definite conclusions but does point to habitat changes that have occurred at Riveredge. Over the years many open areas have undergone succession and matured into early stage forests. As a result, birds like the eastern meadowlark, golden-winged warbler, swamp sparrow and sedge wren haven’t been encountered here during BBS surveys for many years.
If you wish to assist Steve with these surveys or have questions regarding the data please feel free to contact Mary Holleback (firstname.lastname@example.org).