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The Use of Removal Sampling in Comparative Censuses
Author(s) -
Skalski John R.,
Simmons Mary Ann,
Robson Douglas S.
Publication year - 1984
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.2307/1938072
Subject(s) - abundance (ecology) , estimator , statistics , sampling (signal processing) , relative species abundance , efficiency , mark and recapture , abundance estimation , population , sampling design , mathematics , ecology , econometrics , environmental science , biology , computer science , demography , filter (signal processing) , sociology , computer vision
Estimators of proportional abundance (ratio of animal abundance of one population N 2 , to that of another, N 1 , defined as K = N 2 /N 1 ) are derived using constant—effort removal sampling techniques. Based on assumptions about catchability, alternative estimators of K using absolute abundance and catch indices (counts of individual animals captured during a study) are presented. Power curves for comparative censuses using two or three removal samples are presented and the relative efficiency to tag—recapture studies is discussed. Removal sampling is found to be only slightly less efficient than tag—recapture methods if the use of catch indices is permissible; otherwise the efficiency is appreciably less if absolute abundance methods are employed. Analytic procedures are presented which can be used to design comparative census studies. The effects of heterogeneity in the trap response of animals on abundance estimation are discussed.