Poliocephalus poliocephalus

Abstract: The upper plumage of nestling and fledgling C. saturatus horsfieldi and C. poliocephalus poliocephalus was similar, dark blackish brown (DBB) in the former and slaty black (SB) or DBB in the latter. The throat and breast were DBB in young C. s. horsfieldi, while they were banded with SB or DBB and white in young C. p. poliocephalus. The rest of the lower parts were banded with DBB or SB and white in both species, but the bars were obscure and much darker in nestling C. s, horsfieldi. The nestlings and fledglings of the two species in Japan are easily distinguished by the plumages of their underparts.

Abstract: The grey-headed flying fox Pteropus poliocephalus, a nationally vulnerable species, is endemic to coastal eastern Australia, from Maryborough, Queensland, through New South Wales to Melbourne, Victoria. Pteropus poliocephalus forages at night, primarily on eucalypt blossom within 50 km of traditional camps (day roosts), usually in dense, riparian vegetation. Several attempts have been made to track long-distance movements of P. poliocephalus across its extensive and climatically highly variable range, but the technology has been inadequate for tracking at the required speed and scale. Satellite tracking was used to monitor movements of a 2-year-old male P. poliocephalus, trapped at the Currie Park camp in the north of the species' range (28°48′S) from January 2000, and another from its most southerly camp, Melbourne (37°50′S), from April 2000. The first flying fox moved camp 50 km noth-east to Dallas Park, where it stayed until March, then transited at least 15 other camps between 28°12′–32°44′S, before returning to Dallas Park in September. The second flying fox remained in Melbourne until July, then transited at least six other camps to 33°44′S, before returning to Melbourne in January 2001. Both animals made round trips of at least 2000 km, traversing >4° latitude, before returning to their camps of origin, while other animals remained. The study suggests that P. poliocephalus is a partial migrant that uses winds to facilitate long-distance movements, and underlines the importance of management at a national scale.

Abstract: The Hoary-headed Grebe (Poliocephalus poliocephalus) and the New Zealand Dabchick (P. rufopectus) comprise a super- species without close relatives. The former alone has a distinct winter plumage and is smaller and less intensely pigmented. Soft parts colours, wing patterns, and patterns of downy young are described. Little significant geographic variation was found in either species. As in other grebes, sexual dimorphism is greatest in bill measurements of both species. The greatest mensural difference between the two species is in bill length, but males of the smaller species (poliocephalus) have longer bills than females of the larger species. Pattern of downy young and number of fused thoracic vertebrae support a relationship of Poliocephalus with the genus Rollandia.

Abstract: The Hoary-headed Grebe Poliocephalus poliocephalus specialized in feeding on an unpredictable though at times very abundant supply of tiny arthropods. It may be more gregarious than any other grebe, with less developed agonistic behaviour. A strong tendency to cluster may facilitate food-location and reduce predation. Big roosts where the individuals clump densely are formed by night. Courtship rituals are simple, and similar to those of the New Zealand Dabchick P. rufopectus. The two species form a distinct evolutionary line, with the Neotropical White-tufted Grebe Rollandia rolland and Great Grebe Podiceps major as the nearest relatives.