How effective is spotlighting for detecting the greater glider (Petauroides volans)?

The efficacy of spotlighting as a field survey technique for detecting the greater glider (Petauroides volans) was assessed by comparing the precise l ocation of radio-tracked animals with locations determined simultaneously f rom spotlighting searches. Radio-collars were fitted to 20 greater gliders in three eucalypt patches embedded within an extensive radiata pine (Pinus radiata) plantation near Tumut in south-eastern New South Wales. Our succes s rate for detecting collared animals was low, even when survey effort was increased. These findings suggest that spotlighting underestimates actual p opulation size. A further, properly designed study, in different forest typ es is needed to provide precise estimates of the magnitude of the bias in c ounts of P. volans obtained by spotlighting.