Pitohui
Pitohuis | |
---|---|
Hooded pitohui | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
The pitohuis are birds endemic to New Guinea. All six species were formerly classified in the Pitohui genus, classified in the same family. Two species are now classified in the Oriolidae, and three species in the Pachycephalidae (there is one species incertae sedis).
Most taxonomists now separate the species as follows:
Oriolidae
- Variable pitohui, Pitohui kirhocephalus
- Hooded pitohui, Pitohui dichrous
Pachycephalidae
- White-bellied pitohui, Pseudorectes incertus
- Rusty pitohui, Pseudorectes ferrugineus
- Black pitohui, Melanorectes nigrescens
Incertae sedis
- Crested pitohui, Ornorectes cristatus
They 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). These are believed to serve the birds as a chemical defence, either against ectoparasites or against visually guided predators such as snakes, raptors or humans.[1] The birds probably do not produce batrachotoxin themselves. The toxins most likely come from the beetle genus Choresine, part of the birds' diets.[2] Due to their toxicity, Papua New Guineans call the pitohuis rubbish birds as they are not good for eating; in desperate times, though, they can be consumed but only after the feathers and skin are removed and the flesh is coated in charcoal and then roasted. (Piper, 2007)
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 20 subspecies with different plumage patterns have been named. Two of them, however, closely resemble the hooded pitohui.
The birds' bright colours are suggested to be 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 an encounter with either species trains a predator to avoid both.[3]
See also
References
- ↑ (Dumbacher, et al., 1992)
- ↑ (Dumbacher, et al., 2004).
- ↑ (Dumbacher & Fleischer, 2001)
- del Hoyo, J.; Elliot, A. & Christie D. (editors). (2007). Handbook of the Birds of the World. Volume 12: Picathartes to Tits and Chickadees. Lynx Edicions. ISBN 978-84-96553-42-2
- 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. doi:10.1126/science.1439786. 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. doi:10.1098/rspb.2001.1717. PMC 1088837. 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. doi:10.1073/pnas.0407197101. PMC 528779. PMID 15520388.
- Piper, R. Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press
External links
- Fugu, Poison Frogs, and Pitohuis by Harold B. White
- Picture of a hooded pitohui at the Wayback Machine