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Abundance

Some simple estimates of abundance (reference is Krebs, C. J., 1989, Ecological Methodology. Harper & Row, New York).

Jolly-Seber. Enters an array formula that computes the Jolly-Seber estimate of abundance (with confidence limits) based on counts in quadrats or transects. Because this is a dynamic formula, it can be used for a crude power analysis. Simply set out estimated counts in a column and enter the formula in a nearby cell. By testing different counts and sample sizes, you should be able to determine roughly how many quadrats are needed for an accurate population estimate.

Schnabel and Petersen are the Schnabel and Lincoln-Petersen estimates as discussed in Kreb’s Ecological Methodology.


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