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| Pitohui | ||||||||||||
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Pitohui is a genus of birds endemic to New Guinea, belonging to the family Pachycephalidae.
Currently six species are classified in the genus, though current molecular genetics research suggests that significant reclassification of the Pachycephalidae may be needed.
Species
- Variable Pitohui, Pitohui kirhocephalus
Hooded Pitohui, Pitohui dichrous
White-bellied Pitohui, Pitohui incertus
Rusty Pitohui, Pitohui ferrugineus
Crested Pitohui, Pitohui cristatus
Black Pitohui, Pitohui nigrescens
Pitohuis are brightly coloured, omnivorous birds. The skin and feathers of some pitohuis, especially the Variable and Hooded Pitohuis, contain powerful neurotoxic alkaloids of the batrachotoxin group (also secreted by the Colombian poison dart frogs, genus Phyllobates). It is believed that these serve the birds as a chemical defence, either against ectoparasites or against visually guided predators such as snakes, raptors or humans. (Dumbacher, et al., 1992) The birds probably do not produce batrachotoxin themselves. It is most likely that the toxins come from the Choresine genus of beetles, part of the bird's diet.[1] (Dumbacher, et al., 2004)
The Hooded Pitohui is brightly coloured, with a brick red belly and a jet black head. The Variable Pitohui, as its name implies, exists in many different forms, and twenty subspecies with different plumage patterns have been named. Two of them, however, closely resemble the Hooded Pitohui.
It has been suggested that the birds' bright colours are an example of aposematism (warning colouration), and the similarity of the Hooded Pitohui and some forms of the Variable Pitohui might then be an example of Müllerian mimicry, in which dangerous species gain a mutual advantage by sharing colouration, so that an encounter with either species trains a predator to avoid both. (Dumbacher & Fleischer, 2001)
References
- Dumbacher JP, Beehler BM, Spande TF, Garraffo HM, Daly JW (1992). "Homobatrachotoxin in the genus Pitohui: chemical defense in birds?". Science 258 (5083): 799-801. PMID 1439786.
- Dumbacher JP, Fleischer RC (2001). "Phylogenetic evidence for colour pattern convergence in toxic pitohuis: Mullerian mimicry in birds?". Proceedings of the Royal Society of London B 268 (1480): 1971-6. PMID 11571042.
- Dumbacher JP, Wako A, Derrickson SR, Samuelson A, Spande TF, Daly JW (2004). "Melyrid beetles (Choresine): a putative source for the batrachotoxin alkaloids found in poison-dart frogs and toxic passerine birds". Proceedings of the National Academy of Sciences 101 (45): 15857-60. PMID 15520388.
