How well do route survey areas represent landscapes at larger spatial extents? An analysis of land cover composition along Breeding Bird Survey routes

• Published in: The Condor (Los Angeles, Calif.) Calif.), 2017-08, Vol.119 (3), p.607-615
• Main Authors: Veech, Joseph A, Pardieck, Keith L, Ziolkowski, David J
• Format: Article
• Language: English
• Subjects: Abundance; Agricultural land; Animal breeding; anthropogenic; Anthropogenic factors; Bias; bird survey; Birds; Breeding; Buffers; conservation; habitat; Habitats; Human influences; Land cover; Landscape; Ornithology; Pasture; Polls & surveys; RESEARCH ARTICLE; Routes; Spatial analysis; Species composition; survey unit; Vegetation
• ISSN: 0010-5422; 1938-5129; 2732-4621
• DOI: 10.1650/CONDOR-17-15.1

The occurrence of birds in a survey unit is partly determined by the habitat present. Moreover, some bird species preferentially avoid some land cover types and are attracted to others. As such, land cover composition within the 400 m survey areas along a Breeding Bird Survey (BBS) route clearly influences the species available to be detected. Ideally, to extend survey results to the larger landscape, land cover composition within the survey area should be similar to that at larger spatial extents defining the landscape. Such representativeness helps minimize possible roadside effects (bias), here defined as differences in bird species composition and abundance along a roadside as compared to a larger surrounding landscape. We used land cover data from the 2011 National Land Cover Database to examine representativeness of land cover composition along routes. Using ArcGIS, the percentages of each of 15 land cover types within 400 m buffers along 2,696 U.S. BBS routes were calculated and compared to percentages in 2 km, 5 km, and 10 km buffers surrounding each route. This assessment revealed that aquatic cover types and highly urbanized land tend to be slightly underrepresented in the survey areas. Two anthropogenic cover types (pasture/hay and cropland) may be slightly overrepresented in the survey areas. Over all cover types, 92% of the 2,696 routes exhibited “good” representativeness, with