Estimation of proportions and ratios from line transect data

Abstract

If the population of interest in a line transect survey consists of distinct sub-populations, or classes, line transect data can be used to estimate the proportion of the population in each class, or the ratio of the number of individuals in one class to another class. However, if the various classes have unequal overall detectability then the observed ratio or proportion is biased and should be adjusted. Estimators for the desired proportions and ratios are proposed and studied, and procedures for examining the equal detectability hypotheses are discussed.

Keywords:

• line transect
• proportions
• ratios
• unequal detectability