A line transect model for aerial surveys

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We employ a line transect method to estimate the density of the common and Pacific loon in the Yukon Flats National Wildlife Refuge from aerial survey data. Line transect methods have the advantage of automatically taking into account “visibility bias” due to detectability difference of animals at different distances from the transect line. However, line transect methods must overcome two difficulties when applied to inaccurate recording of sighting distances due to high travel speeds, so that in fact only a few reliable distance class counts are available. We propose a unimodal detection function that provides an estimate of the effective area lost due to the blind strip, under the assumption that a line of perfect detection exists parallel to the transect line. The unimodal detection function can also be applied when a blind strip is absent, and in certain instances when the maximum probability of detection is less than 100%. A simple bootstrap procedure to estimate standard error is illustrated. Finally, we present results from a small set of Monte Carlo experiments.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A line transect model for aerial surveys
Series title Biometrics
DOI 10.2307/2532661
Volume 47
Issue 3
Year Published 1991
Language English
Publisher Wiley
Contributing office(s) Alaska Science Center
Description 14 p.
First page 1089
Last page 1102
Country United States
State Alaska
Other Geospatial Yukon Flats National Wildlife Refuge