White-browed Sparrow-Weaver Plocepasser mahali

Identification. The White-browed Sparrow-Weaver is a large brown and white weaver that is fairly common. It has a conspicuous broad white stripe from above the eye backwards, and 2 prominent white wing-bars and wing edgings. In flight, a large white patch on the rump and uppertail-coverts is visible.

Distribution. The White-browed Sparrow-Weaver the most widespread of the sparrow-weavers, occurring in southern and eastern Africa. It has four subspecies:
P. m. mahali in southern Africa (red on the map).
P. m. ansorgei in northern Namibia to Angola (green on the map). This race has broad white tips on the tail feathers.
P. m. pectoralis from Zimbabwe and Zambia to central Tanzania (blue on the map). This race has a reddish-brown back, and the breast feathers have dark triangular centres (see photo above right and here);
P. m. melanorhynchus from northern Tanzania to Sudan (pink on the map). This race has earth-brown upperparts, and black marks on the breast sides.

The White-browed Sparrow-Weaver appears to have increased its range and abundance in many areas (read more here and Kruger). For example, in the Eastern Cape it was first seen on Rookwood farm in the 1980s, and since 2000 has several colonies (see sparrow-weaver colonies on Rookwood here). This species has probably increased in number of nests at Barberspan (see here). The species seems to be increasing in Kenya, e.g. it was described as a new-comer to Ngulia in the past 2 years (VM 1977) and is increasing in Nairobi.

Habitat. The White-browed Sparrow-Weaver inhabits mopane and acacia savanna, with <600 mm annual rainfall. It is also found in riverine fringes and gardens.

Food. The White-browed Sparrow-Weaver feeds on insects and seeds. Insects include termites, weevils, tenebrionid beetles, ants, caterpillars and small moths. Seeds of grasses and cereals are important in winter. It takes bread and other scraps at camp sites.

Breeding. The White-browed Sparrow-Weaver is a colonial, cooperative breeder, living in groups of 2-11 birds. There is a single breeding female in each group, that is replaced by another group member in time. There is a dominant, breeding male that is eventually replaced from outside the group. Helpers related to the breeding pair help defend the territory and feed the young; unrelated helpers only help in group defence of the territory. The average colony size is 16 nests, but may be up to 20 nests in a single tree.

The nest is an elongated retort ball, with a domed roof. It is built only from dry grasses 15-60cm long. One occupied nest contained 983 pieces of grass. About 60% of roosting nests are converted to breeding nests by closing one of the 2 entrances, and then lining with feathers. The nest is placed in trees, 2-8 m above the ground. Mopane and Acacia trees are often favoured. Most nests are placed on the side of the tree away from the prevailing wind. Nest construction takes 10-18 days; and is by both members of the pair and helpers may contribute. Nest-building activity is throughout the year. Its nest sometimes has a longer entrance, as shown right.

Birds like the Ashy Tit Parus griseus, Black-checked Waxbill Estrilda erythronotos and Red-headed Finch Amadina erythrocephala may use their nests for roosting.

Breeding season
throughout year in Kenya and South Africa depending on local conditions in areas of irregular rainfall; mostly Mar-May in E Africa, but Jul-Aug on Laikipia Plateau (Kenya); Nov-Dec in Angola, peak Dec-Mar in Zambia, Oct-Feb in Malawi, May-Jun in Botswana

Nest site
placed 2-8 m above ground in tree such as mopane, Sclerocarya caffra, or acacia (at least six species recorded)

Nest building
Nests built throughout year, but especially after rain; construction taking 10-18 days

Colony size
n/a

Clutch size
2-3

Egg colour
salmon-pink or creamy white, either evenly speckled with red, brown and grey, or markings forming band at thick end

Egg size
average 24.9 x 16.4 mm (South Africa)

Incubation
incubation by female alone, period 14-16 days

Chicks and nestling period
young fed by female alone for first 2-3 days, then also by male and helpers, chicks in nests with helpers grow faster; nestling period 17-18 days in Zambia, 21-23 days in South Africa, 25 days in captivity