Mountain Yellow-Warbler Iduna similis Scientific name definitions

13 cm; 9–15 g. A medium-sized olive-and-yellow warbler with broad bill. Plumage is olive-green above , top of head uniform with mantle; short narrow yellow supercilium above olive-green cheek and ear-coverts; upperwing-coverts olive-green; remiges and twelve tail feathers dark brown, edged yellowish-green; entirely bright yellow below ; iris brown; bill dark brown above, yellowish or pale pinkish to dull ochre below; legs grey or blackish. Sexes alike. Juvenile is browner above than adult, rump and uppertail-coverts tinged cinnamon, paler yellow below.

S South Sudan (Imatongs, Dongatona Mts, Didinga Hills), NE & SW Uganda (Mt Morongole, SW highlands), highlands of E DRCongo, W Rwanda and W Burundi (Rwenzoris S to Itombwe and Mt Kabobo), Kenya (Mt Kulal, Mt Elgon, W & C highlands), N & E Tanzania (Crater Highlands E to Mt Kilimanjaro, and Ngurus and Ukagurus S to Njombe), and Nyika Plateau on Zambia–Malawi border.

Rank growth and bushes along streams or in swampy valleys; edges or clearings in montane forest; secondary growth, heath scrub, bracken-briar and overgrown cultivation. Above 1800 m, to 3400 m in Kenya, 3700 m in E DRCongo.

Sedentary.

Insects, especially flies (Diptera). Often forages low down, but also in middle level thickets and in treetops to 20 m among canopy and creepers. Gleans actively from leaves and branches.

Song a short, varied medley, with sweet whistles, warbled notes and trills, lasting 4–7 seconds, often repeated as series of variations separated by short intervals. Call “cha-cha-cha”.

Breeds mainly in rainy season; eggs laid Apr and Oct in S Sudan, Apr–Jun and Oct in DRCongo, Jul–Aug and Nov in W Kenya, Sept and Dec in Tanzania, and Dec–Feb in Zambia-Malawi. Territorial. Nest a bulky, thick-walled cup built of grass blades and seedheads, mixed with feathers, ferns and moss, bound with cobwebs, and lined with feathers, hair and plant fibres, usually c. 1 m above ground in fork in low shrub or bush. Clutch usually 2 eggs; no information on incubation and nestling periods.

Not globally threatened. Locally common within fragmented range in highlands of E Africa. Reasonably adaptable, and capable of thriving in secondary habitats. Not dependent on forest.