Chestnut Wattle-eye Platysteira castanea Scientific name definitions

10 cm; 11–22 g (quite variable; heaviest birds recorded Equateur, in DRCongo). Very small, plump, almost tailless flycatcher-like bird with eye wattle. Male is mainly black with bluish tinge above , small white spot above eye, rear scapulars edged white, rump feathers long, white; white below , broad black pectoral band; eye wattle purple-grey (becoming purplish black, mauve or red in excitement); iris chestnut or dark red; bill black; legs reddish purple, claws grey. Female has head slate-grey, hindneck, mantle, scapulars and upperwing-coverts chestnut, rump mottled grey, white and chestnut; flight-feathers dark brown, edged chestnut, tail black; throat , neck-sides and upper breast chestnut, chin and belly white; bare parts as male. Immature is like female, but head brown, throat and breast mottled greyish brown, white and (later) rufous, dorsal colour brown (later rufous); eye wattle undeveloped.

S Nigeria E to S South Sudan, W Kenya and NW Tanzania (Bukoba), S to N Angola (N of 10° S), S DRCongo (Kasaji, in Katanga) and extreme N Zambia (Mwinilunga); also Bioko.

Primary and secondary forest, including swampy and flooded woodland, isolated tree clumps, abandoned plantations, but avoids areas with an open understorey; also dense gallery forest on Adamawa Plateau, in Cameroon, and some forest-grassland mosaics. Lowlands, to 1100 m on Bioko, to 1250 m in Cameroon, at least 1500 m in Uganda and to 1800 m in Kenya; in DRCongo, up to 1460 m in Itombwe and to 1600 m in Rutshuru.

Resident.

Arthropods; berries and other small fruits and seeds also recorded. Among insects, beetles (Coleoptera) frequent but many others recorded, including lepidopterans, orthopterans, hymenopterans, mantids (Mantodea), bugs (Hemiptera), cockroaches (Blattodea), termites (Isoptera); other arthropods taken are spiders (Araneae), millipedes (Diplopoda), scorpions (Scorpiones). Noxious prey is initially smashed against perch. Mean prey size for own consumption 18·3 mm, for feeding to young 13·2 mm. Forages at all levels of vegetation to lower canopy, changing preference with season and sometimes in response to presence of congeners; found lower in trees during breeding season. Very active feeder, hopping between branches; takes prey mostly at extremity of branches, with upward sally to snap up prey in brief hovering flight or swoop. Frequently joins mixed-species parties, despite periodic aggression towards other (sometimes substantially larger) insectivores, and usually observed in pairs or small family parties.

Very variable, notes ranging from ringing to wheezing, bleating, grunting, croaking; “gok” or “gogok”, seeming as if produced by distant large bird; also regular series of monotonous “tuck” notes, almost two per second, apparently as territorial song (and very similar to song of Red-rumped Tinkerbird Pogoniulus atroflavus), sometimes duetting with neighbouring territorial male; territorial song faster than that of D. tonsa, with which it also interacts. Wing-fripping and bill-snapping.

Season variable according to locality, but potentially prolonged, e.g. in Uganda, birds in breeding condition in Feb–Aug, and Oct–Nov; elsewhere, eggs in Dec–May and Aug in lowlands of Cameroon (and said to avoid main rainy period); female about to lay in May in Central African Republic; peaks in Sept–Oct and Jan–Feb in Gabon; in DRCongo mainly Feb–Nov (Itombwe), but bird with brood patch in Jun and female with oviduct egg in Sept (in Equateur); juveniles in Mar and Nov–Dec in Angola and in Oct in Zambia. Territorial and monogamous, with pair-bond suggested to be lifelong, but some nests have helpers (young of previous brood). Nest a particularly small tight open cup (outside diameter 55–65 mm, inside diameter 41–42 mm, walls 20 mm wide, 15–25 mm deep), made of vegetable matter, lichens and fungal material (especially Marasmius), also a few dried leaves, bound tightly with spider web, placed 1·5–16 m above ground, usually at end of branch, and hidden under big leaf (secured close to nest rim by spider web). Clutch 1–2 eggs, blue or pale greenish (shiny), with circle of small dark brown, violet or blackish marks at blunt end, size 16–18 mm × 12–13·5 mm, laid at one-day intervals starting up to four days after nest completed; incubation by both sexes (male with brood patch recorded), period 17 days, starting with second egg; young hatch naked with blackish skin, but soon acquire brownish down, nestling period 14–16 days, fed by both adults; young remain in family group for two years (see above). African Emerald Cuckoo (Chrysococcyx cupreus) recorded as brood parasite in Gabon. Low reproductive output from nests studied in Gabon, where eggs were laid in just 13 (of 27) nests observed from building stage, while young hatched in six and fledged in only four, while of 25 eggs laid, only 11 hatched and just eight produced fledglings.

Not globally threatened (Least Concern). Generally common. Common in Cameroon lowland forest, including large forests outside main forest block. One of commonest birds in forest in Gabon: density 36·8–43·1 pairs/km² in good forest intersected by newly build road to 20–25 pairs/km² in degraded forest. Common on Bioko; common in Okapi Faunal Reserve, in E DRCongo; and “found in almost every forest patch” in Angola. In Uganda, commoner and more widespread than sympatric and apparently broadly syntopic D. jamesoni, and study in Budongo Forest Reserve found that the species is significantly more numerous in selectively logged, as opposed to unmanaged primary, forest. The species’ future in Zambia, where discovered as recently as Oct 1976, appears precarious, as by 1995 forest at the original site had been entirely cleared to make way for subsistence agriculture, and the other sites were clearly also threatened.