Philippine creeper

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Philippine creepers
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Suborder: Passeri
Parvorder: Passerida
Family: see text
Genus: Rhabdornis
Species

Rhabdornis grandis
Rhabdornis inornatus
Rhabdornis mystacalis

The Philippine creepers or rhabdornises are small passerine birds. The family is endemic to the Philippines. The group contains a single genus Rhabdornis with three species. They do not migrate other than local movements.

The Philippine creepers are similar in appearance to treecreepers (Certhiidae). They have thin pointed down-curved bills, which they can use to extricate insects from bark, but they have brush-like tongues, which enable them to also feed on nectar. Their behaviour is said[citation needed] to resemble that of tits, to which they are not related, more than the treecreepers. Nests are tree crevices.

The placement of genus Rhabdornis in a family of its own (Rhabdornithidae Greenway, 1967) is not accepted by all authorities, and it is sometimes placed in Certhiidae or Timaliidae. The German name, Trugbaumläufer ("false treecreepers"), reflects this uncertainty. More recently, Zuccon et al. 2006 place them rather surprisingly in a basal clade inside the starlings in the family Sturnidae. Their closest allies seem to be a number of quite plesiomorphic starling lineages mainly from the Asian-Pacific region (such as mynas), so this placement seems as plausible as any other. Judging from biogeography alone, the treecreepers are indeed far less likely to be related to the Philippine creepers than starlings or timaliids, as neither the Certhiidae nor their close relatives expanded into the Wallacea whereas the latter did. Note also the general rarity of small woodpeckers on the Philippines, implying that any bird lineage that would happen to adapt to the same ecological niche was likely to be successful.

Nonetheless, the placement with the starlings requires confirmation. As notoriously confounded by convergent evolution as Philippine creeper anatomy is, the scenario of Zuccon et al. requires the underlying plesiomorphies closer to those present in starlings and thrashers than to those retained in treecreepers and wrens, and vice versa as regards synapomorphies. This has not been tested; in the meantime, it may be noted that the color pattern of Rhabdornis is more similar to that of some Aplonis - a member of the group of starlings supposedly most close to the Philippine creepers - than to that of treecreepers. Both Philippine and treecreepers are cryptic in adaptation to their tree-creeping lifestyle, but this is achieved with a very different camouflage pattern in either. Additionally, they are very distant even among starlings (Zuccon et al. 2006: 340) and may in the end be maintained as a family on their own.

Species

There are two other small bird families with 'treecreeper' or 'creeper' in their name: Australian treecreepers, and treecreepers. The latter are discussed above, the former are an entirely unrelated family of passerine birds.

[edit] References

  • Zuccon, Dario; Cibois, Anne; Pasquet, Eric & Ericson, Per G.P. (2006): Nuclear and mitochondrial sequence data reveal the major lineages of starlings, mynas and related taxa. Molecular Phylogenetics and Evolution 41(2): 333-344. doi:10.1016/j.ympev.2006.05.007 (HTML abstract)

[edit] External links