Birds of Indian Subcontinent

Avian Responses to Observer Clothing Color: Caveats from Winter Point Counts

Publication Type:Journal Article
Year of Publication:1993
Journal:The Wilson Bulletin
Date Published:1993
ISBN Number:00435643
Keywords:Astragalinus, Astragalinus tristis, Baeolophus, Baeolophus bicolor, Carduelis, Carduelis carduelis, Carduelis tristis, Fringillidae, Paridae, Parus, Parus bicolor, Parus carolinensis, Poecile, Poecile carolinensis, Pseudomitris, Pseudomitris tristis, Spinus, Spinus tristis
Abstract:As part of a project to determine optimal methods for censusing winter birds with unlimited-distance point counts, we studied the influence of wearing a hunter-orange vest on richness estimates and species' detection probabilities. We did not find a significant difference in the number of species detected between apparel conditions (vest worn, vest not worn). However, separate detection probabilities for three species were associated with whether or not an orange vest was worn (Carolina Chickadee [Parus carolinensis, P = 0.075]; Tufted Titmouse [P. bicolor, P = 0.009]; American Goldfinch [Carduelis tristis, P = 0.002]). For all three species, detection probabilities were lower when a vest was worn, suggesting that these species were repelled by the orange vest. Movement toward or away from a color, respectively, may generate inaccurate assessments of behavior, habitat use, and abundance. Knowledge about chromotropic responses to observer apparel will enable investigators to design more valid research. A clear benefit of improved designs will be more accurate inferences, which are crucial for conservation efforts and for advancing ornithological science.
Short Title:The Wilson Bulletin
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith