Western spinebill

Western spinebill
Male
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Meliphagidae
Genus: Acanthorhynchus
Species:
A. superciliosus
Binomial name
Acanthorhynchus superciliosus
Gould, 1837

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.[2] 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.[3]

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.

Systematics

First described by John Gould in 1837, the western spinebill is a monotypic species, with only one form found across its range. It forms a superspecies with the closely related eastern spinebill.[4] Scientists believe the two sister species are descended from a shared ancestor whose once widespread populations were separated by climate change. During a past period of desertification, that ancestor species retreated to refuges in the southwestern and southeastern corners of the continent, and evolved into the two present-day spinebill species.[5] Recent DNA studies have shown that the two spinebills belong to a clade which is a sister taxon to all other honeyeaters.[6]

The two are members of the genus Acanthorhynchus, from the Ancient Greek akantha, meaning 'spine' and rhunkhos, meaning 'bill'.[7] The specific name superciliosus is Latin for 'eyebrowed', a reference to the male's bold white supercilium.[8] Early settler George Fletcher Moore reported that the Noongar, southwestern Australia's indigenous people, called this species "buljit".[9]

Description

The female is smaller and plainer than the male.

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),[10][11][nb 1] and in weight from 8–11 g (0.28–0.39 oz).[13] Males are, on average, slightly larger than females.[11] 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.[11] He has a white eyebrow and a black mask, and white outer tail feathers which are 'flirted' in flight.[10] The female is plainer, with a pale rufous nape. Her throat and underparts are variously described as rufous-buff[10] or pale grey,[14] and she lacks the distinctive banding of the male.[10] The immature resembles a plainer female, though with a yellow base to the bill.[14]

Voice

The high, shrill, staccato piping of the western spinebill is transcribed as kleet-kleet[10][11] or kleat-kleat.[14]

Range and habitat

Endemic to the southwestern corner of Western Australia, the western spinebill is found from north of Jurien Bay to Israelite Bay, and inland to an arc described by Moora, Corrigin and Lake Grace. It is common in the understorey of heaths, coastal scrub, woodlands and forest, and in Banksia thickets.[10]

The species is kept in Western Australian aviaries, as the sister species Acanthorhynchus tenuirostris of the east is held in captivity in Sydney, due to the local species being available to avicultural enthusiasts of honeyeaters.[15]

Behaviour

Flowers of Banksia ilicifolia are a favourite nectar source.

The western spinebill is known to be locally nomadic.[10]

Feeding

Like other honeyeaters, the western spinebill feeds primarily on nectar. It feeds for longer time periods—and ingests more nectar—in the first 60 to 90 minutes of each day than it does later in the day.[16]

Banksia ilicifolia is particularly sought over other banksias,[17] which may be foraged, including B. menziesii (although birds do not congregate in greater numbers when this species is flowering),[18] and B. sessilis.[19] The western spinebill has been observed foraging at flower spikes lower down in the tree canopy, possibly to avoid larger and more aggressive honeyeaters.[18]

Breeding

The western spinebill breeds primarily from September to January,[10] though eggs have been noted as early as August, and fledglings as late as March.[13] The female, only very occasionally with help from the male,[13] builds a tidy cup nest from bark, grass, plant stems, and plant down,[10] bound with spider webs to a low bush or tree.[14] The nest, which is sometimes conspicuous,[14] is typically located 1–5 m (3.3–16.4 ft) off the ground.[10] The female lays 1–2 eggs, which measure 17 mm × 13 mm (0.67 in × 0.51 in) on average.[14] These are pinkish or bluish with spots and blotches of chestnut or purplish-brown.[10] The eggs are incubated primarily by the female, only very occasionally by the male. Nestlings are fed by both parents, and fledge after 15 days or so. Both parents continue to feed the fledglings for some time after they leave the nest. The species is one of many known to host the offspring of the pallid cuckoo, a brood parasite.[13]

Note

  1. ^ By convention, length is measured from the tip of the bill to the tip of the tail on a dead bird (or skin) laid on its back.[12]

References

Citations

  1. ^ BirdLife International (2012). "Acanthorhynchus superciliosus". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.
  2. ^ George (Berndt), Elizabeth A.; Margaret Pieroni (illustrations) (2002). Verticordia: the turner of hearts. Crawley: University of Western Australia Press. p. 17. ISBN 1-876268-46-8. In WA ... Western Spinebill (Acanthorhynchus superciliosus) [has] been recorded visiting cultivated plants [Verticordia grandis]
  3. ^ Newland, C. E.; Wooller, R. D. (1985). "Seasonal changes in a honeyeater assemblage in Banksia woodland, near Perth, Western Australia". New Zealand Journal of Zoology. 12 (4): 631–36. doi:10.1080/03014223.1985.10428312. Retrieved 24 November 2010.
  4. ^ Schodde, Richard; Mason, I. J. (1999). Directory of Australian Birds: Passerines. Collingwood, VIC, Australia: CSIRO. ISBN 978-0-643-10293-4.
  5. ^ Newton, Ian (2003). Speciation and Biogeography of Birds. San Diego, CA: Academic Press. pp. 341–42. ISBN 978-0-08-092499-1.
  6. ^ Christidis, Les; Boles, Walter (2008). Systematics and Taxonomy of Australian Birds. Collingwood, VIC, Australia: CSIRO. p. 186. ISBN 978-0-643-06511-6.
  7. ^ Jobling 2010, p. 30
  8. ^ Jobling 2010, p. 374
  9. ^ Moore, George Fletcher (1884). Diary of Ten Years Eventful Life of an Early Settler in Western Australia. London, UK: M. Walbrook. p. 101. ISBN 9780855641375. LCCN 43042806.
  10. ^ a b c d e f g h i j k Pizzey, Graham; Knight, Frank (1998). Birds of Australia. London: HarperCollins. p. 396. ISBN 0-00-220132-1.
  11. ^ a b c d Simpson, Ken; Day, Nicolas (1984). Field Guide to the Birds of Australia. London, UK: Christopher Helm. p. 240. ISBN 978-0-7470-3023-2.
  12. ^ Cramp, Stanley, ed. (1977). Handbook of the Birds of Europe, the Middle East and North Africa: Birds of the Western Palearctic, Volume 1, Ostrich to Ducks. Oxford University Press. p. 3. ISBN 0-19-857358-8.
  13. ^ a b c d Higgins, Christidis & Ford 2008, p. 583
  14. ^ a b c d e f Slater, Peter; Slater, Pat; Slater, Raoul (2003). The Slater Field Guide to Australian Birds. Frenchs Forest, NSW, Australia: Reed New Holland. p. 294. ISBN 978-1-877069-00-0.
  15. ^ Shephard, Mark (1989). Aviculture in Australia: Keeping and Breeding Aviary Birds. Prahran, Victoria: Black Cockatoo Press. p. 241. ISBN 978-0-9588106-0-9.
  16. ^ Collins, B. G.; Clow, H. (1978). "Feeding Behaviour and Energetics of the Western Spinebill, Acanthorhynchus superciliosis (Aves: Meliphagidae)". Australian Journal of Zoology. 26 (2): 269–277. doi:10.1071/zo9780269.
  17. ^ Whelan, Robert J., Robert J.; Burbidge, Allan H. (1980). "Flowering phenology, seed set and bird pollination of five Western Australian Banksia species". Austral Ecology. 5 (1): 1–7. Bibcode:1980AusEc...5....1W. doi:10.1111/j.1442-9993.1980.tb01225.x.
  18. ^ a b Ramsey, M.W. (1989). "The seasonal abundance and foraging behaviour of honeyeaters and their potential role in the pollination of Banksia menziesii". Australian Journal of Ecology. 14 (1): 33–40. doi:10.1111/j.1442-9993.1989.tb01006.x. ISSN 0307-692X.
  19. ^ Collins, Brian G.; Grey, James (1989). "Preferential Foraging by Honeyeaters in the Jarrah Forest of Western Australia". Ostrich. 60: 39–47. Bibcode:1989Ostri..60S..39C. doi:10.1080/00306525.1989.9639614.

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