|
Case Summary for:
Submission No 217: Glossy Swiftlet Collocalia esculenta; Warraber Is QLD, 31 January 1988. Submitted by Mike Carter. Verdict: Accepted This submission involves a description of a bird sighted by a single observer on Warraber Island (also known as Sue Island) in the Torres Strait 31st January 1988. Observations were brief, involving three sightings between 15.10 and 15.30 under fine clear conditions. Binoculars were used at a distance estimated to be approximately 50 meters, although the bird was also seen at much closer range without optical aids. The description detailed a small swiftlet with slender body and wings, an all dark plumage with paler underparts particularly the belly. There was no clear division between the belly and the remainder of the upperparts. The upperparts appeared uniformly dark and importantly there were no white areas on the rump or throat. The flight was described as lazy and slow, with few wing beats and more gliding and drifting than with the larger swiftlets. The tail was noted to look slightly cleft when closed tight and yet somewhat square when opened out. The committee was satisfied that this species was one of the smaller swiftlets and quickly narrowed the identification to either C.linchi Cave Swiftlet or C.esculenta. It was generally agreed that the description and available reference material constitutes considerable difficulty in ruling out C.linchi in full. However the committee felt that C.esculenta is far more likely than C.linchi to occur in the Torres Strait as it is common in nearby southern Papua New Guinea. Moreover, there are a number of well documented previous occurrences of C.esculenta from both the Torres Strait islands and Cape York, so the submission fits well into the established pattern of vagrancy for this species in Australia.
References and Bibliography
Tony Palliser |