carcass (version 1.7)

ettersonEq14: Equation 14 of Etterson (2013) Ecological Applications 23, 1915-1925

Description

Calculates the probability that a carcass that has fallen in the search area during n regular or irregular search intervals is found by a searcher.

Usage

ettersonEq14(s, f, J)

Value

the probability that a carcass that has fallen into the search area during the study is found by the searcher.

Arguments

s

persistence probability, probability that a carcass persists a specific time interval (normally a day), i.e. daily persistence probability. Note that the same time unit as for the length of the search interval must be used.

f

searcher efficiency, i.e. the probability that a carcass present in the search area is found during one search.

J

a vector containing the lengths of the search intervals.

Author

M. A. Etterson

Details

This formula can handle irregular search intervals. It assumes constant persistence time and constant searcher efficiency. Confidence intervals are not yet implemented, but a Monte Carlo confidence intervals will be calculated by the function estimateN with the argument form="etterson".

References

Etterson, M.A. (2013) Hidden Markov models for estimating animal mortality from antropogenic hazards. Ecological Applications, 23, 1915-1925.

See Also

ettersonEq14v1 ettersonEq14v2 pkorner phuso perickson

Examples

# in case of regular search intervals, the calculations below give the same results
ettersonEq14(s=0.8, f=0.8, J=c(3,3,3,3,3))
pkorner(s=0.8, f=0.8, d=3, n=5)


 # in case of irregular search intervals the function ettersonEq14 is more appropriate
ettersonEq14(s=0.8, f=0.8, J=c(3,5,1,4,2))
pkorner(s=0.8, f=0.8, d=mean(c(3,5,1,4,2)), n=5)