TwoPassDepl: Two Pass Depletion Abundance Estimator

Description Usage Arguments Value Author(s) References Examples

Description

a function to estimate abundance based on a two pass depletion method

Usage

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TwoPassDepl(data, rmInvalid=FALSE, p.threshold=0.2)

Arguments

data

dataframe with two columns containing the counts from each pass

rmInvalid

if TRUE, make any abundances NA where the probability of capture is estimated to be below p.threshold

p.threshold

the user-defined cutoff for declaring an estimate invalid. Set to 0.2 as a default

Value

N.hat

- estimate of abundance

N.hat.SE

- standard error of the estimate of abundance

p.hat

- estimate of the probability of capture

Author(s)

Kevin See, QCI, Seattle, WA

References

Lockwood, Roger N. and J. C. Schneider. 2000. Stream fish population estimates by markand-recapture and depletion methods. Chapter 7 in Schneider, James C. (ed.) 2000. Manual of fisheries survey methods II: with periodic updates. Michigan Department of Natural Resources, Fisheries Special Report 25, Ann Arbor.

Examples

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data(depl.data)
# pull out examples with two-pass depletion data
two.pass.data = subset(depl.data, n.pass==2, select=c('pass.1', 'pass.2'))
# estimate abundance
TwoPassDepl(two.pass.data)

KevinSee/SiteAbundances documentation built on May 7, 2019, 12:30 p.m.