Black-necked Wattle-eye Platysteira chalybea Scientific name definitions

c. 9 cm; 11–13 g. Tiny, stub-tailed flycatcher-like bird. Adult male is characterized by black throat , breast , upperparts and wings with metallic bottle-green gloss, white rump, creamy-yellow to pale yellow belly to undertail-coverts, greyish-black flanks, and black thighs; bill black, broad and flat, iris chestnut-brown with large bright emerald-green wattle (larger above eye) and legs and feet greyish blue to greyish purple. Female differs only in being duller and less glossy, greyer on upperparts, with much smaller and paler eye-wattle . Juvenile has dull greyish to sooty-black upperparts, whitish underparts showing no yellow, and broad tawny stripe on central throat. Immature acquires with slight greenish gloss above, has chin, throat and upper breast pale tawny to rufous-buff, with mottled border forming a narrow breastband, rest of underparts whitish except greyish flanks; bill blackish, with pale tip, eye greyish brown, with small wattle, and legs and feet grey-brown to greyish purple; throat and breast gradually darken. Distinctive compared to formerly conspecific D. blissetti and D. jamesoni, as lacks chestnut on lower cheeks, has underparts pale golden-yellow, and eye-wattle is emerald-green (see also Taxonomy, above).

Found in dense undergrowth of primary and secondary forest, with earliest stages of secondary forest preferred in Gabon, as well as early-stage regeneration flooded forest on islands, overgrown vegetation around villages, plantations, liana tangles, etc. Occurs immediately to E of Mt Cameroon, at 900–1950 m on Mt Kupé and 1200–1700 m in Rumpi Hills; 900–1900 m on Bioko.

Insects of many orders, commonly beetles (Coleoptera), also lepidopterans (moths and caterpillars), orthopterans (grasshoppers), hymenopterans (ants), large flies (Diptera), termites (Isoptera); also spiders (Araneae). Prey items 8–35 mm long, mainly 10–15 mm. Keeps to lowest levels of vegetation, generally below 4 m; carefully inspects piles of branches and dead leaves, fallen logs, and large stems in thickets; stretches upwards from perch to pick prey from leaves, or makes short sallies or sally-hovers. Usually in pairs or small family parties. Recorded in mixed-species flocks, especially during non-breeding season.

Song comprises two types; first, a short descending and oft-repeated series of 3–6, high-pitched notes  , e.g. “fi-fi-fu, he-he-her-her-hur”, which is sometimes preceded by a more excitable “wikwik” or “ptiuc-ti-di-titititu”, and the second, used in more high-intensity situations, a c. 1-minute-long series of even-pitche, ringing notes at rate of c. 3/second, e.g. “fu-fu-fu-fu-…”, which (like D. jamesoni) can recall Olive-green Camaroptera (Camaroptera chloronota). In flight, gives a “kweck-kweck” or even faster “ptedecptedecptedc”; also heard are nasal churrs, a repeated, high-pitched “ptick-ptick…” in excitement, a rapid “pwit-pwit-pwit-…” in alarm, and bill-snaps and wing-whirring sounds during display to accompany territorial song, as bird flies back and forth, with rump feathers fluffed-out.

In Cameroon, young (also female with brood patch and another incubating) in Mar; nestbuilding in Jul and young in Jan in Gabon; male in breeding condition in Aug in Angola; gonads enlarged in Oct–Nov on Bioko. Territorial year-round. Monogamous, but helper (immature) observed at nest. Role of sexes generally unknown. Nest a small cup of vegetable fibres, small stems, rootlets, pieces of bark and dead leaves, with lichen and decaying leaves on outer wall, bound with cobwebs and lined with finer material, built under leaf in fork of sapling or at junction of two vines, below a large leaf, 0·4–1 m above ground; dimensions 40–45 mm inside diameter, 30 mm cup depth and 45 mm high. Clutch two eggs, whitish-green, with circle of brown to brown-grey spots at blunt end, size 17·5–18 mm × 12–12·5 mm; incubation period at least 14 days, by female alone (provisioned by male); nestling period 15 days, with young fed by both sexes, being blackish brown to greyish black above, wing-coverts tipped buff, and underparts white.

Not globally threatened (Least Concern). Range appears somewhat fragmented. Typically, a rather local inhabitant of tall forest, known from Takamanda Forest Reserve, Rumpi Hills and E of Mt Cameroon and recorded in lower part of Mbam-Djerem National Park and large gallery forests farther E, also common around Mt Kupé area in montane forest, and recently recorded in Korup National Park. Relatively common in Gabon, 7·1–13·5 pairs/km², but uncommon in Angola.