[MARMAM] ABSTRACT: Estimating Abundance From One-Dimensional Passive Acoustic Surveys

hwhitehe at dal.ca hwhitehe at dal.ca
Thu Aug 13 08:10:14 PDT 2009


The following paper may be of interest.

A .pdf of this paper (and others) is available at:

http://whitelab.biology.dal.ca/labpub.htm

Hal Whitehead

Estimating Abundance From One-Dimensional Passive
Acoustic Surveys


ABSTRACT Conventional distance sampling, the most-used method of 
estimating animal density and abundance, requires ranges to
detected individuals, which are not easily measured for vocalizations. 
However, in some circumstances the sequential pattern of detection of
vocalizations along a transect line gives information about the range of 
detection. Thus, from a one-dimensional acoustic point-transect survey
(i.e., records of vocalizations detected or not detected at regularly spaced 
listening stations) it is possible to obtain a useful estimate of density or
abundance. I developed equations for estimation of density for one-
dimensional surveys. Using simulations I found that for the method to have
little bias when both range of detection and rate of vocalization need to be 
estimated, stations needed to be spaced at 30-80% of the range of
detection and the rate of vocalization should be >0.7. If either the range of 
detection or rate of vocalization is known, conditions are relaxed,
and when both parameters are known the method works well almost 
universally. In favorable conditions for one-dimensional methods,
estimated abundances have overall errors not much larger than those from 
conventional line-transect distance sampling. The methods appeared
useful when applied to real acoustic data from whale surveys. The 
techniques may also be useful in surveys with nonacoustic detection of
animals.

JOURNAL OF WILDLIFE MANAGEMENT 73(6):1000-1009; 2009
DOI: 10.2193/2008-303

HAL WHITEHEAD, Department of Biology, Dalhousie University, Halifax, 
NS B3H 4J1, Canada





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