Choice of survey platforms and technique for broad-scale monitoring of kangaroo populations

Abstract

The commercial harvesting of kangaroos requires the regular monitoring of populations using a technique that is precise and reasonably accurate. Because of the broad distribution of the species and the generally large management areas, wildlife authorities rely on some form of aerial survey to estimate both relative and absolute kangaroo densities. Methodology for fixed-wing aircraft was developed in the 1970s and has generally become standardized in areas where it is applied. The technique allows for broad-scale coverage of management areas and involves flying at a set height, speed and direction and counting in fixed (generally 200 m) strips. An alternative method using a different survey platform (helicopter), sampling procedure (monitor block) and survey technique (line transect) has been developed recently. The technique has advantages over the standard fixed-wing survey method in accuracy, species applicability and repeatability with disadvantages in cost, time taken and in coverage of overall spati...