Southern Brown-throated Weaver Ploceus xanthopterus

Introduction

The Southern Brown-throated Weaver was formally described by 2 authors: Karel Johan Gustav Hartlaub, a German physician and ornithologist, and Friedrich Hermann Otto Finsch, a German naturalist and colonial explorer.The description was published in a book about birds collected on Baron Carl Klaus von der Decken’s travels in east Africa, but the book included birds from other collections, including the Southern Brown-throated Weaver.

The Southern Brown-throated Weaver was collected by Sir John Kirk, a Scottish physician and naturalist.

Kirk was part of David Livingstone’s Zambesi expedition from 1858 to 1864, travelling from the mouth of the Zambesi upstream, and also exploring the Shire River, a northern tributary of the Zambesi.

On a return from Lake Nyasa (Lake Malawi), the expedition boat was stuck in the Elephant Marsh on the Shire River during Nov-Dec 1861. Kirk collected the Southern Brown-throated Weaver while stranded here. When the rains came, the river started to rise and the expedition coninued, reaching the Mozambican coast in early Jan 1862.

Kirk also collected many other birds and mammals along the Zambesi on this expedition, and sent most of these specimens to the British Museum.

The first illustration of the Southern Brown-throated Weaver was of an adult male by Cabanis (1884). This was followed by a colour painting, of the head of a male, by Sharpe (1890).

Scientific citation

Hyphantornis xanthopterus Hartlaub & Finsch 1870 Vog. Ost. Afr. p.399 Shire Valley, Nyasaland.

Meaning of names

xanthopterus, Greek: xanthos, yellow; -pteros, winged.

First English name

Yellow-winged Weaver Bird (Layard 1884).

Alternate names

Brown-throated Golden Weaver, Golden Weaver, Zambezi Brown-throated Weaver.

Collector

Sir John Kirk.

Date collected

Dec 1861.

Locality collected

Shire Valley = Elephant Marsh, Malawi.

Type specimens

There is a type specimen in the British Museum (BM 1863.12.30.7).

Southern Brown-throated Weaver Ploceus xanthopterus is a small weaver, with a short tail. The breeding male is the only weaver in its range with a brown face and throat which are demarcated from the yellow head. Females, non-breeding males and young birds have a distinct cinnamon wash on the upperparts, and the bill is two-toned. It does not overlap in range with the similar Northern Brown-throated Weaver of East Africa.There are three subspecies of the Southern Brown-throated Weaver, with disjunct distributions (see map above, based on Birds of Africa):
P. x. xanthopterus, found in Tanzania, Malawi, Mozambique south to the Zambezi River, and NE Zimbabwe (see green on map).
P. x. castaneigula, in the Caprivi in Namibia, the Okavango in Botswana and the upper Zambezi River (see blue on map). This subspecies is larger than the nominate race, and the male has the crown orange-yellow, in contrast to the green mantle.
P. x. marleyi, in Mozambique from the Save River, southwards, SE Zimbabwe, South Africa (see red on map). In this subspecies the male has the crown bright yellow, with little contrast with the mantle; and the throat is tawny rather than chestnut.

There is one out of range record, Nest Record Card 100170, from Chiredzi in SE Zimbabwe.

The Southern Brown-throated Weaver inhabits reeds and tall aquatic vegetation in wetlands. It forages in nearby riparian forest and other dense vegetation, but usually not far from water. It is usually found in small flocks (less than 20 birds), and it rarely associates with other weavers. Like other weavers, it undergoes a complete moult after breeding, but males start moulting while there are still eggs and chicks in nests. The furthest distance moved (from ringing data) is 8 km, and the oldest bird is 13 years (see here).

The diet of the Southern Brown-throated Weaver is seeds, including grasses; berries; insects including moths, beetles, grasshoppers, caterpillars; flowers; and also bread in gardens.

The Southern Brown-throated Weaver is colonial, with 10-300 nests per colony. It is polygynous, with males attracting 2-3 females. Females are double-brooded (in Malawi), using a new nest for the second clutch. The nest is an oval, with the entrance below, and without a porch. Nests are mostly built in reedbeds of Phragmites, Typha or Papyrus and rarely in trees. One colony of 20-30 nests was placed in a small Acacia overhung a birdbath. It may nest alongside Southern Red Bishop.

Breeding season
Mar in Tanzania, Feb-Mar in Zambia, Oct-Apr in Malawi, Oct-Nov in Botswana, Nov-Mar (mainly Jan-Feb) in Zimbabwe and Dec in Mozambique; mainly Nov-Jan, with some earlier and later records, in South Africa

Nest site
placed chiefly in bed of Phragmites reeds, bulrushes or papyrus, occasionally in tree, c. 2.5 m above water or ground

Nest building
woven by male, lined by female

Colony size
Colonial, with up to 300 nests together

Clutch size
2-3 eggs (average 2.4 in Malawi)

Egg colour
usually plain dark chocolate-brown or olive-brown, sometimes blue-green and heavily marked with grey-brown specks, or greenish-white with heavy red-brown markings

Egg size
average size of 45 eggs 21 x 14.5 mm (South Africa)

Incubation
incubation by female only, period 14-17 days

Chicks and nestling period
chicks fed by female alone, nestling period 14-19 days