Environmental and Ecological Statistics

, Volume 5, Issue 1, pp 81–91

Line transect sampling of Karner blue butterflies ( Lycaeides melissa samuelis)

  • J. A. Brown
  • M. S. Boyce

DOI: 10.1023/A:1009620105039

Cite this article as:
Brown, J.A. & Boyce, M.S. Environmental and Ecological Statistics (1998) 5: 81. doi:10.1023/A:1009620105039


Line transect sampling is an effective survey method for estimating butterfly densities because it provides unbiased estimates of site-density (provided key assumptions are met), and estimates are comparable among sites. For monitoring Karner blue butterflies in Wisconsin, USA, comparable estimates are required because each year a different selection of sites will be monitored. Annual state-wide indices of species abundance can be derived from the site-surveys and compared to previous year's indices to monitor trends. We advocate that line transect sampling is preferable to Pollard-Yates transects as a survey technique for monitoring Karner blue butter- flies. The Pollard-Yates surveys do not adjust for diferences in site detectability. As a consequence, estimates of among-site from Pollard-Yates surveys can be biased. © Rapid Science 1998

density estimation distance sampling detection function monitoring Pollard-Yates 

Copyright information

© Chapman and Hall 1998

Authors and Affiliations

  • J. A. Brown
    • 1
  • M. S. Boyce
    • 2
  1. 1.Department of StatisticsMassey University, Private Bag 11 222Palmerston NorthNew Zealand
  2. 2.College of Natural ResourcesUniversity of Wisconsin Stevens PointUSA

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