About Petrophassa albipennis Gould, 1841
The white-quilled rock pigeon (Petrophassa albipennis Gould, 1841) is a large pigeon ranging in color from mid-brown to reddish-brown. Its wings measure 122 to 145 mm, and its bill measures 11.0 to 14.5 mm in length. The nominate subspecies P. a. albipennis weighs 117 to 156 grams, while the smaller subspecies P. a. boothi weighs between 103 and 142 grams. The species has white spots on its chin and forehead, and grey orbital skin. While its common name comes from the white wing panels visible when it is in flight, its facial markings are also distinctive. There are thin, pale lines that run across the face: one from the base of the upper mandible that curves above and behind the eye, and another from the lower mandible that runs below the eye and curves across the sides of the head. Subspecies albipennis, which occurs mostly in Western Australia, has large white patches on its wings, while subspecies boothi, found in the Northern Territory, has smaller wing patches. The IUCN Red List classifies the white-quilled rock pigeon's conservation status as Least Concern (LC), but the species is listed as Near Threatened (NT) in the Northern Territory. This pigeon inhabits rocky escarpments and gorges, and moves easily among rocks and boulders. It shares a distinctive general shape and posture with the chestnut-quilled rock pigeon: it often perches on a prominent rock or ledge, holding its body horizontally, holding its tail clear of the ground, and holding its wings drooped below its tail. The white-quilled rock pigeon's defining characteristics were first recorded from type specimens collected by officers of HMS Beagle, and were detailed by the ship's commander John Lort Stokes in his account of the Beagle's Australian voyages. The species flies with a characteristic loud clattering of wings, and often glides from one high prominence to another. It feeds in adjacent grassy woodlands, but returns to its escarpment habitat when startled.
