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.

Experiments in Aerial Survey

Graeme Caughley, Ronald Sinclair and Donald Scott-Kemmis
The Journal of Wildlife Management
Vol. 40, No. 2 (Apr., 1976), pp. 290-300
Published by: Wiley on behalf of the Wildlife Society
DOI: 10.2307/3800428
Stable URL: http://www.jstor.org/stable/3800428
Page Count: 11
  • Download ($42.00)
  • Subscribe ($19.50)
  • Cite this Item
Experiments in Aerial Survey
Preview not available

Abstract

By use of balanced experiments amenable to analysis of variance we explored the effects of several factors on the accuracy of aerial survey estimates of animal density. Speed, height above ground, transect width, and observers had significant effects, whereas time of day, fatigue of observers, and length of survey were less important. We tested the hypothesis that a regression of observed density on speed, height, and transect width could be extrapolated backward to estimate true density at zero values of these survey variables. The results were generally consistent with this expectation. The uses of this technique are outlined, with examples, in the context of correcting an observed density to an estimate of true density, of calibrating one observer against another, and of comparing the results from aerial surveys flown at different speeds and heights, and with different widths of transect. The field experiments utilized red kangaroos (Megaleia rufa) at unknown densities and domestic sheep at known densities. Laboratory experiments were performed on dots of known density projected onto a screen. Before the model is accepted as generally applicable it must be tested against several other species in a variety of habitats.

Page Thumbnails

  • Thumbnail: Page 
290
    290
  • Thumbnail: Page 
291
    291
  • Thumbnail: Page 
292
    292
  • Thumbnail: Page 
293
    293
  • Thumbnail: Page 
294
    294
  • Thumbnail: Page 
295
    295
  • Thumbnail: Page 
296
    296
  • Thumbnail: Page 
297
    297
  • Thumbnail: Page 
298
    298
  • Thumbnail: Page 
299
    299
  • Thumbnail: Page 
300
    300