Population estimation using line transects?

[Daniel Grosboll]

Does anyone know of anyone who has tried using "distance sampling" (i.e.
Buckland et al. 2001; Burnham et al. 1980) to estimate populations of
butterflies?  This is an often used method for vertebrates that essentially
translates line transect counts and the distance to organisms from the line
into a population estimate for a defined sampled area.  It would obviously
be more labor intensive than the often used Pollard walk but that only gives
an index of abundance.  I need a population estimate and given what we think
is a very small population size, I can't potentially impact the population
by doing capture-mark-recapture.  Any suggestions?

Dan Grosboll
Endangered Species Recovery Biologist
Washington Department of Fish and Wildlife
P.O. Box 385 
Littlerock, WA 98556
360.273.1820
dangrosboll at earthlink.net 


References
Buckland, S. T., D. R. Anderson, K. P. Burnham, J. L. Laake, D. L. Borchers,
and L. Thomas. 2001. Introduction to distance sampling: estimating abundance
of biological populations. Oxford: Oxford University Press.

Burnham, K. P., D. R. Anderson, and J. L. Laake. 1980. Estimation of density
from line transect sampling of biological populations. Wildlife Monographs
72:202.




 
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