Artamidae

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Artamidae
Piedbutcherbird.jpg
Pied butcherbird
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Superfamily: Malaconotoidea
Family: Artamidae
Subfamilies

Artamidae is a family of passerine birds found in Australia, the Indo-Pacific region, and Southern Asia. It includes 23 extant species in four genera and two subfamilies: Artaminae (with only one genus, the woodswallows) and Cracticinae (currawongs, butcherbirds, peltops and the Australian magpie). Artamids used to be monotypic, containing only the woodswallows, but it was expanded to include the family Cracticidae in 1994. Some authors, however, still treat the two as separate families.[1] Some species in this family are known for their beautiful song. Their feeding habits vary from nectar sucking (woodswallows) to predation on small birds (pied currawong).

Taxonomy and systematics[edit]

The Artamids are part of the Malaconotoidea superfamily, consisting of a vast diversity of omnivores and carnivorous songbirds widespread through Australasia.[2] Artamids has been divided over time into two subfamilies. With little studies and dispute on the inclusion of Cracticidae to the Artamidae family, it appears they have been placed in this respective joint position due to lack of evidence or knowledge. Jerome Fuchs and colleagues extensively analysed both the mitochondrial and nuclear DNA of the Artamid family. The results suggested that the group may have existed in Australasia for 33.7 to 45 million years, dating back to the late Eocene [3]

Kurrartapu is a fossil species known from a proximal tarsometatarsus from the Early Miocene at Riversleigh in central Queensland. It was around the same size as the black butcherbird and had features in common with Strepera and Cracticus.[4]

Distribution and habitat[edit]

Artamid species occur throughout Australasia with most species occurring in Australia and New Guinea.[5] The social interactions of Artamids vary from the solitary black butcherbird, which lives alone or in a single pair, to the white-breasted woodswallow, which lives in flocks or loose colonies. While some species are sedentary, staying close to suburbia and ample food sources, others are migratory or even nomadic like the masked woodswallow, moving around in response to changes in climate such as rainfall or temperature.[6] Their range of habitats varies between species but most will adapt to rain forests, woodlands, coastal scrubs (swallows), watercourses, playing fields, pastoral land and paperbark mangroves (butcher birds). Some species have adapted to urban landscapes where they contend with fragmented and degraded remnants of native vegetation.[7]

Morphology[edit]

The Australian Magpie showing its plumage.

Artamids are a diverse family showing a notable variation in size and shape. They range in size from the short stocky Fiji woodswallow Artamus mentalis and the Ashy woodswallow Artamus fuscus, both of which are around 19 centimetres (7.5 in) in length and weigh about 40 grams (1.4 oz), to the larger grey currawong Strepera versicolour, which measures up to 50 cm (20 in) and weighs up to 440 g (16 oz).

The beaks of artamids are strong and robust, sometimes known as a generalist beak. Like falcons, some of the subfamily Cracticinae possess a sharp projection along the upper mandible, with a corresponding notch on the lower mandible. This hook-like tooth is used to catch and fatally sever the bodies of insects, lizards and small mammals.[8] A trait of artamids (and all passerines) is that it possesses an anisodactyl foot arrangement: three toes are directed forward and one toe directed backward, enabling them to perch on horizontal objects such as tree branches and power lines.[9]

Because they possess a syrinx, Artamids, in particular the pied butcherbird, the pied currawong and the Australian magpie, are able to create subtle songs.[10] Uniquely among other perching birds, some woodswallows possess special feathers called powder down.[11] The tips of the barbules on powder down feathers disintegrate, forming fine particles of keratin, which appear as a powder, or "feather dust", among the feathers and spread when preening.[12] The plumage of the Artamids is relatively dull, most birds showing a combination of greys, earthy browns, blacks and patches of white. There is seldom sexual dimorphism in plumage, but when it occurs the males are brighter and the females appear dull or resemble juveniles. In many species juveniles have a distinctly duller plumage.[13] The notarium, a fused vertebra of the shoulder in birds that helps brace the chest against the forces generated by the wings, is a distinctive osteological trait that has evolved repeatedly in the passerines including the Artamadae family.[14]

Behaviour[edit]

Black-faced woodswallows roosting as a group

Members of the Artamidae, especially the woodswallows, have been known to cluster together during the night and day. Accounts have appeared in literature from the earliest days of ornithological documentation in Australia.[15] The habit of clustering is believed to serve two purposes: retaining body heat during cooler weather and as a social form of camouflage. Another unusual behaviour exhibited by an Artamid is the swooping on humans by magpies. While there is not much information on this behaviour, previous studies have suggested that magpie attacks on humans may be strongly influenced by hormone levels. However, recent investigations indicate that the stress hormone corticosterone may cause magpie aggression and swooping.[16]

Diet and feeding[edit]

All are omnivorous to some degree: the butcherbirds mostly eat meat; Australian magpies usually forage through short grass looking for worms and other small creatures; currawongs are true omnivores, taking fruit, grain, meat, insects, eggs and nestlings and woodswallows feed on insects and nectar. [17] Most are opportunistic feeders, such as the woodswallows, taking advantage of the flowering plants such as the silky oak Grevillea robusta, box mistletoe Amyema miquelii,[18] and the long flowering stalks of Xanthorrhoea spp. or insects such as cockroaches or spiders eaten by the black butcherbird. Bigger species such as the grey currawong prey on many vertebrates, including frogs, lizards such as skinks, and juveniles of smaller birds such as the native eastern spinebill Acanthorhynchus tenuirostris or the introduced house sparrow Passer domesticus.[19] The evolution of vertical feeding zones (feeding strategies subdividing into vertical space, e.g. upper, mid- and ground canopy) is noted among the Artamidae. While species will sometimes overlap vertical terrains, most woodswallows use the upper canopy, feeding on insects and pollen, while magpies and currawongs tend to use the ground or swoop down from the mid-story pouncing on their food. Being accomplished in extractive foraging is another trait of the Artamidae; although they are opportunistic feeders they are very methodical forages, often following a set routine.[20]

Threats[edit]

Habitat loss[edit]

A picture of a roadkill magpie.

With developments occurring more regularly the most critical threat to the artamids is habitat destruction and habitat fragmentation. This loss of habitat reduces vegetation corridors (connective parcels of vegetation) that are used for feeding, breeding and safely travelling.[21] After fragmentation, habitats are often too small or are limited by the construction of roads. These barriers cause population stresses and species can become vulnerable to localised extinction.[22] Habitat loss and fragmentation can force species into urbanised habitats that impose their own dangers such as cars. Roadkill is considered to contribute significantly to the population decline of many bird species, especially opportunistic feeders like the Artimidae, which often unconsciously swoop down on an insect without seeing an oncoming car.[23]

Introduced species[edit]

In Australia introduced species have caused the greatest number of extinctions. Exotic feral animals such as cats can have a negative effect on Artamids. Ground-foraging species such as the magpie often fall prey to cats in urban environments.[24]

Species of Artamidae[edit]

There are two subfamilies with four genera recognised. In 2013 a molecular study showed the Australian magpie to be the sister taxon to the black butcherbird.[25]

References[edit]

  1. ^ Les Christidis & Walter E. Boles (2008). Systematics and Taxonomy of Australian Birds. CSIRO Publishing. p. 174. ISBN 978-0-643-06511-6. 
  2. ^ Cracraft, Joel, Barker F. Keith, Braun, Michael, Harshman, John, Dyke, Gareth J., Feinstein, Julie, Stanley, Scott, Cibois, Alice, Schikler, Peter, Beresford, Pamela, García-Moreno, Jaime, Sorenson, Michael D., Yuri, Tamaki, Mindell, David P. (2004). "Phylogenetic relationships among modern birds (Neornithes): toward an avian tree of life". In Cracraft J, Donoghue MJ. Assembling the tree of life. New York, New York: Oxford University Press. pp. 468–89. ISBN 0-19-517234-5. 
  3. ^ Fuchs, Jérôme; Irestedt, Martin; Fjeldså, Jon; Coulouxe, Arnaud; Pasquet, Eric; Bowie, Rauri C.K. (2012). "Molecular phylogeny of African bush-shrikes and allies: tracing the biogeographic history of an explosive radiation of corvoid birds". Molecular Phylogenetics and Evolution. 64 (1): 93–105. PMID 22475817. doi:10.1016/j.ympev.2012.03.007. 
  4. ^ Nguyen JM, Worthy TH, Boles WE, Hand SJ, Archer M (2013). "A new cracticid (Passeriformes: Cracticidae) from the Early Miocene of Australia". Emu. 113 (4): 374–382. doi:10.1071/MU13017. 
  5. ^ Rowley, Ian; Russell, Eleanor (2009). "Family Artamidae (Woodswallows)". In del Hoyo, Josep; Elliott, Andrew; Christie, David. Handbook of the Birds of the World. Volume 14: Bush-shrikes to Old World Sparrows. Barcelona: Lynx Edicions. pp. 286–307. ISBN 978-84-96553-50-7. 
  6. ^ Burnie, David (2012). "Nature Guide (Smithsonian Nature Guides)". Melbourne: Dorling Kindersley: 330–337. ISBN 978-0-7566-9041-0. 
  7. ^ Davis, R.A & Wilcox, J.A (2013). "Adapting to suburbia: Bird ecology on an urban-bushland interface in Perth, Western Australia [online].". WA: Pacific Conservation: 110–120. ISSN 1038-2097. 
  8. ^ Ferguson-Lees, James; Christie, David A. Raptors of the World. London: Christopher Helm. p. 66. ISBN 0-7136-8026-1. 
  9. ^ Stefoff, Rebecca (2008). "The Bird Class", Marshall Cavendish Benchmark
  10. ^ Howley, Ian (1991). Forshaw, Joseph, ed. Encyclopaedia of Animals: Birds. London: Merehurst Press. pp. 226–227. ISBN 1-85391-186-0. 
  11. ^ Podulka, Sandy; Rohrbaugh, Ronald W.; Bonney, Rick, eds. (2003). Home Study Course in Bird Biology, second edition. Cornell Laboratory of Ornithology. p. 55 (Glossary). 
  12. ^ Lowery Jr. GH; JP O'Neill (1966). "A new genus and species of Cotinga from eastern Peru" (PDF). The Auk. 83 (1): 1–9. doi:10.2307/4082975. 
  13. ^ Gluckman, Thahn-Ian (2014). "Pathways to elaboration of sexual dimorphism in bird plumage patterns". Linnean Society: 262–273. ISSN 0024-4066. 
  14. ^ James, H.F (2009). "Repeated evolution of fused thoracic vertebrae in songbirds. The Auk". Waco: Ornithology Society of Northern America: 862–872. ISSN 0004-8038. 
  15. ^ Wood, V.J (1970). "Observations of the clustering of little wood-swallows Artamus minor.". Queensland: Sunbird: 59–64. ISSN 1037-258X. 
  16. ^ Warne,R.M; Jones,D.N; Astheimer,L.B (2010). "Attacks on humans by Australian magpies (Cracticus tibicen): territoriality, brood-defence or testosterone?". Melbourne: CSIROPUBLISHING: 28. ISSN 0158-4197. 
  17. ^ Barker, R.D (1990). "Food of Australian Birds 2". Melbourne: CSIROPublishing: 345–350. ISBN 0-643-05115-5. 
  18. ^ Watson, David (2011). Mistletoes of Southern Australia. Melbourne: CSIRO Publishing. p. 199. ISBN 978-0-643-10083-1. 
  19. ^ Barker, R.D.; Vestjens, W.J.M. (1984). The Food of Australian Birds: (II) Passerines. Melbourne University Press. pp. 364–66. ISBN 0-643-05115-5. 
  20. ^ Kaplan, Gisela (2004). Australian Magpie: Biology and Behaviour of an Unusual Songbird. CSIRO PUBLISHING. p. 86. ISBN 978-0-643-09068-2. 
  21. ^ Gill, F. (1995). Ornithology. W.H Freeman and Company, New York. ISBN 0-7167-2415-4.
  22. ^ Moore R., Robinson W., Lovette I., Robinson T. (2008). "Experimental evidence for extreme dispersal limitation in tropical forest birds". Ecology Letters. 11 (9): 960–968. doi:10.1111/j.1461-0248.2008.01196.x. 
  23. ^ Hobday Alistair J., Minstrell Melinda L. (1998). "Distribution and abundance of roadkill on Tasmanian highways: human management options". Wildlife Research. 35. 
  24. ^ Blumstein D., Daniel J. (2005). "The loss of anti-predator behaviour following isolation on islands". Proceedings of the Royal Society of London Series B-Biological Sciences. 272: 1663–1668. PMC 1559846Freely accessible. PMID 16087420. doi:10.1098/rspb.2005.3147. 
  25. ^ Kearns, Anna; Joseph, Leo; Cook, Lyn G. (2013). "A Multilocus Coalescent Analysis of the Speciational History of the Australo-Papuan Butcherbirds and their Allies". Molecular Phylogenetics and Evolution. 66 (3): 941–52. PMID 23219707. doi:10.1016/j.ympev.2012.11.020.