Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Statistical Methods for Aerial Surveys Using the Double-Count Technique to Correct Visibility Bias

Louis-Paul Rivest, Francois Potvin, Helene Crepeau and Gaetan Daigle
Biometrics
Vol. 51, No. 2 (Jun., 1995), pp. 461-470
DOI: 10.2307/2532934
Stable URL: http://www.jstor.org/stable/2532934
Page Count: 10
  • Read Online (Free)
  • Download ($14.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Statistical Methods for Aerial Surveys Using the Double-Count Technique to Correct Visibility Bias
Preview not available

Abstract

In double-count surveys two observers search the sampled area for the species of interest. The presence of the two observers permits one to calculate a survey-specific correction for visibility bias. This correction factor can be negatively biased, because animals difficult to see for one observer are also difficult to see for the other. This paper investigates methods for reducing this bias. One solution is to classify, during the survey, the animals seen according to variables potentially influencing their visibility. Statistical methods are proposed to evaluate the efficiency of such a classification. Another proposal to reduce the bias of double-count estimators is to use parcel-specific correction factors. Variance estimators for double-count estimators of population totals are proposed; three variance components are identified. The proposed techniques are illustrated using data collected in a double-count deer survey carried out on Anticosti Island in the Gulf of St. Lawrence.

Page Thumbnails

  • Thumbnail: Page 
461
    461
  • Thumbnail: Page 
462
    462
  • Thumbnail: Page 
463
    463
  • Thumbnail: Page 
464
    464
  • Thumbnail: Page 
465
    465
  • Thumbnail: Page 
466
    466
  • Thumbnail: Page 
467
    467
  • Thumbnail: Page 
468
    468
  • Thumbnail: Page 
469
    469
  • Thumbnail: Page 
470
    470