A Double-observer approach for estimating detection probability and abundance from avian point counts as described in Nichols et. al. (2000).
Nichols, J. D., J. E. Hines, J. R. Sauer, F. W. Fallon, J. E. Fallon, and P. J. Geglund
A Double-observer Approach for Estimating Detection Probability and Abundance from Point
Counts. The Auk 2000; 117(2): 393-408.
