White-throated Nightjar Eurostopodus mystacalis: First record for the Port Moresby Area

On 11 August 1987 several members of the PNGBS were looking for night –birds on the Pacific Adventist campus, c.10km east of Port Moresby at c.70m. At 21:30 a large nightjar was seen perched on a bare branch. It was observed for about 15 minutes with the aid of a powerful spotlight from a distance of about 30m. During this time it made three flights, returning to the same perch each time. It was larger than either of a pair of Large-tailed Nightjars Caprimulgus macrurus which were seen at the same time. It showed no white markings either in the wing nor on the underside of the tail. The undertail coverts and undersides of the tail were quite strongly barred. A bird matching this description was seen in the same place on 3 September 1987. After consulting various reference books (Beehler et al. 1986; Coates 1985; Slater et al. 1986) this bird was identified as a White-throated Nightjar Eurostopodus mystacalis. It was seen by nine observers, none of whom had had any previous experience of the species.

Six species of nightjar have been recorded in New Guinea and its satellite islands (Beehler et al. 1986). Of these, five were rejected for the following reasons: 1) The Large-tailed Nightjar is the common nightjar of the savanna around Port Moresby. In flight it shows distinct white markings in the wing and on the underside of the tail; 2) Two species, Jungle Nightjar C.indicus and Spotted Nightjar E.argus have yet to be recorded in PNG, although both are migrants and could occur. Both show distinct white wing patches and the male Spotted Nightjar has white in the tail. 3) Two all dark nightjars, both endemic to New Guinea, can be rejected by size and habitat. The Mountain Nightjar E.archboldi frequents montane rain forest and has not been recorded below 2000m (Coates 1985). The Papuan Nightjar E.papuensis is found almost exclusively in lowland rainforest. Both are similar in size to Large-tailed Nightjar.

A race of the White-throated Nightjar E.m.mystacalisis a migrant to New Guinea from its breeding grounds in eastern Australia. It has been recorded infrequently in PNG with sightings from Western Province through the highlands to the north coast but this is the first sighting for south-east New Guinea. There has been one previous ‘possible’ record for the Port Moresby area when a Nightjar showing small white wing patches and lacking white in the tail was flushed from the road near Brown River in August 1986 (Field Guides Inc, 1988). I suspect this species has been overlooked in the past and is not just a vagrant to the Port Moresby area.

Beehler, B.M., T.K. Pratt & D.A. Zimmerman. 1986. Birds of New Guinea. Princeton University Press.
Coates, B.J. 1985. The Birds of Papua New Guinea. Vol 1. Dove Publications.
Field Guides Inc. 1988. Field Guides Inc tour of Papua New Guinea 1986. Muruk 3:23-24.
Slater, P., P.Slater & R.Slater. 1986. The Slater Field Guide to Australian Birds. Rigby.

First published in Muruk 3(2): 55-56