Estimating density from surveys employing unequal-area belt transects

Fixed-width belt transects employed in surveys of irregular shaped regions will differ in length and, therefore, in area. When estimating density from such a sample, the unequal transect areas must be taken into account. A de nsity estimator dividing the mean number of objects (e.g., plants or animal s) per transect by the mean transect area is recommended. An alternative es timator, the mean density per transect, is applicable for equal-area transe cts but often has undesirable properties for unequal-area transects. The re commended density estimator is identified as a ratio estimator, and its sta ndard error is derived from ratio estimation theory.