ECOLOGY OF THE WESTERN WHIPBIRD PSOPHODES-NIGROGULARIS IN WESTERN-AUSTRALIA

The Western Whipbird Psophodes nigrogularis at Two Peoples Bay is the only known surviving population of the subspecies nigrogularis. The preferred habitat is thicket, a two to three metre high formation of varied floristic composition. Other vegetation associations are used infrequently, although all nests were found in dense health adjacent to areas of thicket. As with other populations, structure, not floristic composition, was the important factor in habitat selection. In the absence of fire, the population has steadily increased since the mid-1960s and in 1982, was of the order of 100 pairs. Western Whipbirds occupy overlapping home ranges of 10-19 ha with core areas ranging from 1.5-2.4 ha. Pair bonds are long-lasting and the pair maintains its home range from year to year. Each sex has its own distinctive song type and the female frequently joins the male to sing a duet. Clutch size was two and all clutches were started between late July and early September. Incubation lasts 21 days and the nestlings fledge when about 12 days old and stay with their parents for about two months. Some juveniles undergo a post-fledging moult to assume adult plumage. Future conservation of the species is dependent primarily on appropriate management of fire.