Wattle-eye

Wattle-eyes and batises
Common Wattle-eye
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Suborder: Passeri
Family: Platysteiridae
Sundevall, 1872
Genera

Megabyas
Bias
Pseudobias
Platysteira
Batis
Lanioturdus

Platysteiridae is a family of small stout passerine birds of the African tropics. The family contains the wattle-eyes, batises and shrike-flycatchers. They were previously classed as a subfamily of the Old World flycatcher family Muscicapidae.

These insect-eating birds are found in usually open forests or bush. They hunt by flycatching, or by taking prey from the ground like a shrike. The nest is a small neat cup low in a tree or bush.

Contents

Distribution and habitat

The Platysteiridae are arboreal birds, primarily of the woodlands and forests of sub-Saharan Africa. A single genus, Pseudobias, is endemic to Madagascar, the rest of the family is restricted to mainland Africa and the surrounding islands. The shrike-flycatchers and the genus Dyaphorophyia are birds of dense forest, the rest of the wattle-eyes are found in woodland, and the batises range across all habitats except the densest forests of the Congo Basin and the driest deserts. The Pririt Batis and Pygmy Batis are able to live in highly arid environments with some cover, and the White-fronted Wattle-eye favours mangrove forests in Angola. Many species in the family have adapted to human altered habitats. The family has its highest diversity around the equatorial regions, with half the known species being located in Tanzania and almost half also ranging in he Democratic Republic of the Congo and Kenya.

The family is overwhelmingly sedentary. However there are a few exceptions; the African Shrike-flycatcher is probably an intra-African migrant, as it is absent from some parts of its range during parts of the year. In addition some batis species undertake season migrations as well as some local movements due to changing local conditions.

Morphology

The Platysteiridae are small to medium sized passerines. They have short legs and an upright stance while perched. The tail length is variable, with the Dyaphorophyia wattle-eyes and batises having short tails and the Platysteria wattle-eyes and shrike-flycatchers possessing longish tails. The bill is flat and hooked at the end, and generally wide with well-developed rictal bristles. With the exception of a few batises the plumage of the family is sexually dimorphic. Overall the family has white undersides and dark, speckled upperparts, with many species sporting a band across the chest. A few wattle-eyes depart from this pattern and possess brightly coloured plumage. The plumage on the back of some genera are erectile, giving the family the alternative name of puffback flycatchers. The iris of the batises and the Black-and-white Shrike-flycatcher is brightly coloured and used in communication, becoming more brightly coloured when the adults are excited. In the wattle-eyes the supra-orbital wattles above the eyes, which give them their name, are used for communication. In addition the family is highly vocal, giving a range of whistles, harsh calls and duets.

Diet

The most important component of the diet of all species is insects, although spiders, millipedes and scorpions are also taken, and there are even records of small lizards being consumed. Amongst the insect prey a number of different types are eaten; beetles, grasshoppers and other Orthoptera, flies, mosquitoes, wasps, termites, mantises and others all being recorded. Prey is taken by members of the family either as individuals or in family groups. Some species will also forage as part of mixed species feeding flocks, a technique that has been shown to confer some advantages.[1] The different species and genera use a variety of methods to obtain prey, ranging from foliage-gleaning to flycatching.

Conservation and threats

One species, the Banded Wattle-eye, is considered threatened by human activities. The species has a restricted range in Cameroon that is vulnerable to forest clearance and is listed as endangered by the IUCN.[2] Two further species are considered near-threatened, the Verreaux's Batis and the White-fronted Wattle-eye; both species are threatened by habitat loss. Some species are also very poorly known, and one species, the Dark Batis, was only identified as a species in 2006.[3]

Platysteiridae in taxonomic order

Based on del Hoyo et al. (2006)

The White-tailed Shrike Lanioturdus torquatus, once considered to be part of the family, probably belongs belong with bushshrikes (Malaconotidae).

References

  1. ^ Thomson RL & Ferguson JWH (2007) "Composition and foraging behaviour of mixed-species flocks in two adjacent African woodland habitats: a spatial and temporal perspective" Ostritch 78(1): 65-73
  2. ^ BirdLife International (2007) Species factsheet: Platysteira laticincta. Downloaded from http://www.birdlife.org on 25/2/2008
  3. ^ Fjeldsa J, Bowie RCK, Kiure J (2006) "The forest batis, Batis mixta, is two species: description of a new, narrowly distributed Batis species in the Eastern Arc biodiversity hotspot" Journal of Ornithology 147(4): 578-590

External links