Estimating non-breeding season bird abundance in prairies: A comparison oftwo survey techniques

Surveying birds during the non-breeding season in prairie environments can be difficult because birds are less visible and vocal during this period th an they are during the breeding season. We compared the effectiveness of us ing fixed-radius point counts and rope-dragging transects for surveying non -breeding birds and determining their relative abundances in the Florida Ev erglades, from November 1997 through January 1998. Effort (person work hour s) was compared using species-effort and abundance-effort curves. Relative abundances of total birds, American Bittern (Botaurus lentiginosus), Sedge Wren ( Cistothorus platensis), Common Yellowthroat (Geothlypis trichas), an d Seaside Sparrow (Ammodramus maritimus mirabilis) were greater using trans ects. Abundances of other common species were similar using both techniques . More species were detected on transects than on point counts. When consid ering effort involved, transects detected more total species, but point cou nts detected a greater total number of birds. Overall, transects took more effort to cover similar amounts of habitat. Differences in detection using these two techniques may be attributed to species-specific behaviors. Resea rch focused on non-breeding season bird communities should consider using r ope-dragging transects in appropriate habitat because point counts may unde restimate abundances of some species.