Sampling in Aerial Survey

Abstract

Sampling procedures appropriate to aerial survey [of large animals] were compared firstly in terms of the statistical efficiency and secondly according to their operational practicality. Sampling without replacement is more precise than sampling with replacement, but it requires a standard of navigation often impossible to achieve in practice. Systematic sampling can lead to biased standard errors but that must be weighed against its practical advantages when animal distributions are mapped. Fragmented cluster sampling returns unbiased estimates but autocorrelation between units within clusters (transects) biases the standard errors. Except in special circumstances, transect sampling is more efficient than quadrat sampling.