Western spinebill

The western spinebill (Acanthorhynchus superciliosus) is a honeyeater found in the heath and woodland of south-western Australia. Ranging between 12–16 centimetres (4.7–6.3 in) long, it weighs around 10 grams (0.35 oz). It has a black head, gray back and wings, with a red band behind its neck and from its throat to its breast. Its curved bill is long and slender.

Like other honeyeaters, the western spinebill feeds on nectar. It tends to obtain its nectar from lower shrubs than most other honeyeaters, including Banksia, Dryandra, Grevillea, Adenanthos, and Verticordia. It also feeds from trees of Banksia and Eucalyptus, and from herbs such as Anigozanthos. In addition to nectar, it feeds on insects that it captures in the air or on plants.

It is a frequent visitor to Adenanthos obovatus, and its territories are smaller when they contain more shrubs of this species. Male spinebills often contest their territory borders with other males, and allow females to live within them. These territories range from 0.2 to 0.5 hectares in size. With their long curved bills, western spinebills are the only honeyeaters able to gain nectar out of the tube-like flowers.

It breeds from September to January, in a nest made from bark, plant stems, down and spider web. It lays 1–2 eggs, usually incubated by the female.

The western spinebill is a small honeyeater with a slender, curved bill. It ranges in length from 12 to 16 cm (4.7 to 6.3 in), and in weight from 8–11 g (0.28–0.39 oz). Males are, on average, slightly larger than females. The sexes differ somewhat in plumage. The male is dark olive-grey above with a chestnut nape. Below, his throat and breast are chestnut, edged below with a white band and a black band; his abdomen is buff. He has a white eyebrow and a black mask, and white outer tail feathers which are 'flirted' in flight. The female is plainer, with a pale rufous nape. Her throat and underparts are variously described as rufous-buff or pale grey, and she lacks the distinctive banding of the male. The immature resembles a plainer female, though with a yellow base to the bill.

The high, shrill, staccato piping of the western spinebill is transcribed as kleet-kleet or kleat-kleat.