Introduction

Smith described the Red-billed Buffalo-Weaver from Kurrichane area. In Smith's Illustrations he expands on the locality given in the type description: 'It was not till after we had passed to the northward of the 25th degree of south latitude that we discovered this bird' (Smith 1841a). Sclater (1930) restricted the type-locality to Kurrichaine, a peak 20 km north of Zeerust. Clancey (1964) restricted it to Zeerust, a town that did not exist in Smith's day.

In Smith's diary (Kirby 1940), Smith's first and only reference to the species appears on 1 August 1835. Smith left Tolane on 28 July and followed the Great Marico River to Eerstepoort, which was reached on 8 August. Smith provides daily travel times, permitting an approximate locality to be calculated for 1 August as c.25 00'S, 26 23'E (Oschadleus 2007). This buffalo-weaver was not recorded at Zeerust during the atlas (Harrison et al. 1997), but was recorded rather frequently along the Marico River. Thus the type locality is best described as Great Marico River in North West Province.

The first illustration of a Red-billed Buffalo-Weaver was published by Andrew Smith in 1841 in his well known work, Illustrations of the Zoology of South Africa, being painted by George Henry Ford. The next illustration was published in Reichenbach (1863), being of a male in a similar pose to Ford's illustration.

Scientific citation

Meaning of names

First English name

Alternate names

Collector

Date collected

Locality collected

Type specimens

Identification. The Red-billed Buffalo-Weaver is a large, black or brownish weaver. It differs from the White-billed Buffalo-Weaver in bill colour, being red in the male Red-billed Buffalo-Weaver, orange-yellow to horn-brown in the female and immature. The male Red-billed Buffalo-Weaver is black and the female is dark brown with the underparts mottled brown and white. Immatures are similar to the female but paler brown above, with grey cheeks.

Buffalo-Weavers are unique among weavers (and most birds) in that they have a solid phalloid organ on the belly in front of the cloaca. The organ is larger in males than females - the function of this organ during their prolonged copulation is not entirely certain.

Buffalo-Weavers do not normally associate with buffalo but by a twist of chance, Andrew Smith (who first described the Red-billed Buffalo-Weaver) first saw this species associating with buffalo in North West Province, South Africa.

Distribution. The Red-billed Buffalo-Weaver is found in southern and East Africa. There is a small zone of overlap in East Africa with the White-billed Buffalo-Weaver. The Red-billed Buffalo-Weaver is divided into two subspecies:
B. niger niger found in southern Africa (red on the map).
B. niger intermedius found in East Africa (green on map). This race has narrow white bases to the primary feathers, ie. the white wing panel is smaller than in the nominate race; the bill colour of the male may be variable, though is usually red.

There have probably not been any major range changes for this species in historical times, but it is probably more common where it can choose man-made nest sites within its range.

Habitat. The Red-billed Buffalo-Weaver inhabits savanna, dry thornveld and woodland, including dry mopane and mixed acacia-baobab woodland. It needs large trees for nesting, which may account for its patchy distribution in many areas.

Food. The Red-billed Buffalo-Weaver feeds mainly on insects, particularly grasshoppers and caterpillars, but also takes seeds and fruit. The young are fed with insects only. It forages primarily on the ground where it runs or hops. It may join mixed flocks of other species to forage.

Breeding. This species is usually polygynous, with one male and several females occupying a nest.

Nests are built on large trees, often baobabs. Nests are also built on man-made structures, including windmills and electricity pylons. One particularly unusual site that has not been documented in the literature is a radio mast - see photo (right).

The female incubates the eggs. Nests may be infested with mites and other invertebrates. Raptors sometimes nest on top of buffalo-weaver nests and a variety of smaller birds, especially Red-headed Finches, may take over a nest chamber, eg. PHOWN 196.

Range changes in SA

1. Range expansion westwards from Kathu to Askham
The blue grid cells on the western edge represents a large westward range expansion (between SABAP1 and SABAP2) from Kathu and the Botswana border west to Van Zylsrus and as far as Askham, a distance of about 100km. There is also a PHOWN record from Askham based on the 2010 Google Streetview, indicating nest building and possible breeding.

2. Range extinction in the Free State
The two red cells in the Free State represent the isolated population that was present around Bloemhof Dam, Free State. Birds were first seen in 1981 and nests were seen in 1986. The last published report appears to be from May 2000 and the species no longer occurs here (SABAP2).

3. Range stable along the 26S line of latitude
In South Africa it is found mostly north of 26S (although it ranges to 26S in the western and eastern parts of its range). The 26S line divides the grassveld (south) from the savanna (north) in this area. The Red-billed Buffalo-Weaver is clearly absent south of Pretoria, as in the past.

4. Range stable but low density in eastern corridor
The eastern population of the Red-billed Buffalo-Weaver in South Africa extends southwards in the savanna corridor from Mpumulanga, through the lowlands of eastern Swaziland, and into northern KwaZulu-Natal. The southernmost record is from the Zululand Rhino Reserve. The earliest published record from this corridor is of nests seen in July 1951. An earlier record is a specimen collected on 29 May 1937 in north-eastern Swaziland, suggesting that the species has occurred here in historical times, although early authors did not list it from here. The buffalo-weaver occurs at a very low density in this corridor, with the estimated population being 80 birds in Swaziland.

Range changes elsewhere