The grey-headed honeyeater (Ptilotula keartlandi) is a species of bird in the family Meliphagidae. It is endemic to Australia.
Nomenclature, taxonomy and evolutionary history
First described as Ptilotis keartlandi in 1895 by Australian ornithologist Alfred John North, the grey-headed honeyeater is named in honour of the ornithological collector George Arthur Keartland, who collected the type specimen. The taxonomy of the species has been complex since its description. For example, the species was listed in the genus Meliphaga in 1926 by the Royal Australian Ornithological Union Official Checklist of Birds, and then in the genus Lichenostomus by Schodde in 1975. Most recently, the grey-headed honeyeater has been placed in the genus Ptilotula, which contains five other Australian species that all share characteristically plain faces, subtended by a black proximal and yellow or white distal plume across the side of the neck. The generic name Ptilotula derives from Ancient Greek 'feather' and the diminutive of 'ear'.
While the species in Ptilotula occupy a wide range of forest, woodland, arid and semi-arid habitats, they share a common ancestor, which inhabited the dry woodlands of central Australia. A fossil leg-bone from an unnamed Pliocene species found in Riversleigh, Queensland, described by Walter Boles, may well belong to this ancestor.
Description and identifying features
Grey-headed honeyeaters are relatively small for honeyeaters with a total body length of and a weight of . Individual wing length ranges from , the tail is long, and the bill is in length.
Adults have a distinctive grey crown above a black facial mask with the nape and remaining upper body parts coloured dark fawn-grey. The black facial mask extends from the base of the bill to the rear of the ear coverts, and comprises black lores, eye rings, feathers behind the eye, and grey-black ear coverts. The base of the mask is bordered by a thin, bright yellow plume which extends below and behind the ear coverts and a pale yellow, moustachial stripe located between the lores and throat.
The bill is black, short and slightly down-curved with a yellow base on the lower mandible, although it may become fully black during breeding. The iris is black to dark brown, while the gape is yellow, turning black during breeding.
The breast, belly, flanks, and throat are light olive-yellow streaked with brown, while the rump is light grey-brown. The flight feathers are olive-brown, edged with olive-yellow, which gives the wing a yellow panel when folded. The tail feathers are dark olive-brown edged in olive-yellow. There are ten primary flight feathers, ten secondaries and twelve tail feathers.
There is no plumage difference between the sexes; however, there is some sexual dimorphism, as males are slightly heavier and larger than females. There is no geographical variation in plumage across the species range.
Juveniles have similar plumage to adults, but are generally paler with a lighter grey-brown face mask. Juveniles also have grey-black bills with an orange-brown base, yellow gapes, and a lighter grey crown. Juveniles partially moult into immature plumage soon after fledging and, while immature plumage is similar to adult plumage, juvenile tail and flight feathers are retained, and immatures can be identified by the presence of fault bars in the tail. Moult into adult plumage occurs in the first year.
The grey-headed honeyeater produces a continuous, peevish chip call when feeding, and a wee-wee-wee song. Other vocalisations include a loud, single kwoyt and chee-toyt, which is possibly only emitted during breeding.
Distribution and habitat
The grey-headed honeyeater has an extensive range covering much of central arid and semi-arid Australia. The extent of occurrence is estimated at 4,360,000 square kilometres.
The grey-headed honeyeater mostly frequents Eucalyptus scrub and woodlands in stony hill country and timbered gullies within ranges; however, it can be observed on sand-plains, when vegetation is flowering. The species has also been recorded in mulga and mallee woodlands, riverine areas dominated by River Red Gum (Eucalyptus camaldulensis), and occasionally in Mitchell grasslands.
The grey-headed honeyeater is thought to be largely sedentary; however, it undertakes nomadic movements in response to flowering events. While these movements are predominately local, some larger movements have been recorded. For example, one individual was recorded in East Point, Darwin, 270 kilometres north of its previously documented range, following major Eucalyptus flowering events.