Effects of Observer Variability on the Census of Birds

During surveys of the avifauna of south-eastern New South Wales, five persons were involved in the counting of birds using a strip transect method. Although efforts were made to standardize procedures and to ensure that each person had about the same ability to identify birds, there were differences between observers which affected census results. In this paper the differences between observers are described and discussed with respect to their effects on census results. These data indicate that differences between observer search patterns and their individual behavioural traits may considerably affect census results. Observer variability is an important source of error in bird census work and survey teams in particular need to be aware of the problem. Procedures for reducing observer error are presented.

>> Download Abstract | File Size: 96 KB
>> Download Complete PDF | File Size: 2 MB