Dark-backed Weaver Ploceus bicolor

Weaver species list / RELATED SPECIES: Bar-winged Weaver / Brown-capped Weaver / Dark-backed Weaver / Golden-naped Weaver / Maxwell’s Black Weaver / Olive-headed Weaver / Preuss’s Weaver / Red-bellied Malimbe / Red-headed Malimbe / Red-headed Weaver / Usambara Weaver / Yellow-capped Weaver / Yellow-legged Weaver / Yellow-mantled Weaver

IUCN: Least concern Discovery: 027

Categories: long tube, fruit, gum, nectar, Nest use, palm

Discovery

Dark-backed Weaver, figure from Jardine 1836

 

Dark-backed Weaver distribution, type locality circled

 

Introduction

The Dark-backed Weaver was formally described by Louis Jean Pierre Vieillot, a French ornithologist. Vieillot already described it under a different name in 1818, but the name was not valid, and at first he thought it came from America. In 1819 he gave the valid name and noted that the specimen came from Senegal, but the Dark-backed Weaver does not occur west of Cameroon as was thought by early authors. Shelley 1887 first realised that the actual type specimen in Paris fitted birds from eastern South Africa, and later this was further restricted to the Eastern Cape.The Dark-backed Weaver was first collected by Francois Le Vaillant, who travelled in South Africa in 1781-84, and reached the Eastern Cape in 1782, where the Dark-backed Weaver occurs. When Le Vaillant returned to Europe, most of his specimens where sold or given to Coenraad Jacob Temminck, who had sponsored Le Vaillant’s travels. Temminck produced a catalogue of these birds in 1807 and briefly described the Dark-backed Weaver, without providing a scientific name, but calling it “Le verdier a ventre jaune” (Greenfinch with a yellow belly). He noted that it came from “Africa, Cape of Good Hope” (which includes the Eastern Cape).

Vieillot based many of his descriptions on the work of Temminck 1807, but included a scientific name.

Later Jacques Pucheran (1854), a French zoologist, noted that the Dark-backed Weaver type had been in the collection of Louis Dufresne, a French ornithologist and taxidermist at the natural history museum in Paris. Either the type had been transferred or Le Vaillant had more than 1 specimen, and kept one for the Paris museum, since Le Vaillant was friends with Dufresne.

The collection of Louis Dufresne was sold to the University of Edinburgh in 1819 (and later moved to the Royal Scottish Museum). The first illustration of this species to be published, was by William Jardine in 1836, a Scottish naturalist, who had access to the Scottish collection. In addition to the Dufresne specimen (Jardine did not know the apparent source as Dufresne), Jardine also had other specimens from Dr Andrew Smith.

 

William Jardine, figure from wikipedia

Scientific citation

Ploceus bicolor Vieillot 1819 Nouv. Dict. Hist. Nat., nouv. ed., 34:127 Senegal, errore = S Africa, vide Hartert 1907a. Restricted to Zuurberg, Addo, E Cape by Roberts 1931.

Meaning of names

bicolor Latin: bicoloured, two coloured (bi-, twice, double; color, colour).

First English name

Yellow-bodied Loret (Jardine 1836).

Alternate names

Black-backed Weaver, Forest Weaver, Grey-backed Weaver, Hinge Bird, Solitary Weaver-bird, Spot-headed Weaver.

Collector

Le Vaillant.

Date collected

1782, when Le Vaillant was in the Eastern Cape.

Locality collected

Eastern Cape, around Zuurberg.

Type specimens

Type specimen may be in the Royal Scottish Museum.

 

The above is based on Weaver Wednesday 2, a weekly series about the discovery of each weaver species.
This species text first appeared as Weaver Wednesday [144] – Discovery [27]: Dark-backed Weaver on 2015-03-18

1. Basic biology

Dark-backed Weaver
Dark-backed Weaver, adult, nominate race
Dark-backed Weaver
Dark-backed Weaver, juv with adult

Identification. The Dark-backed Weaver Ploceus bicolor is bright yellow below and dark above, the throat is solid black or mottled black and yellow. The sexes are alike (photo above). Juveniles (photo above) are duller than adults, have a mottled throat, and pale bill. The wing edges are dark (unlike Clarke’s Weaver).

Distribution. Seven subspecies of the Dark-backed Weaver are recognised, although many more have been proposed (see map above, based on Birds of Africa):
P. b. bicolor in E Cape to KwaZulu-Natal in South Africa (see yellow on map).
P. b. tephronotus in SE Nigeria, Cameroon, Bioko Island, Gabon and western Congo (see dark green on map). The crown and nape are brownish black, mantle slate-grey, and the throat is brownish black flecked with grey.
P. b. amaurocephalus in Angola and southern DRC (see blue on map). The crown and cheeks are brownish black, mantle and throat grey.
P. b. mentalis in South Sudan, NE DRC, Uganda, and western Kenya (see grey on map). The back is dark grey, crown and cheeks black, throat black or sometimes yellow and black.
P. b. kigomaensis in Rwanda, Burundi, east and SE DRC, Zambia, extreme SW Tanzania (see light green on map). The throat feathers are tipped with yellow but throat is more blackish than amaurocephalus.
P. b. kersteni in S Somalia, coastal Kenya, E Tanzania south to Rufiji River, and Zanzibar Island (see orange on map). The upperparts are entirely black.
P. b. stictifrons, coastal Tanzania from Kilwa southwards, S Malawi, E Zimbabwe, Mozambique to northern KwaZulu-Natal in South Africa (see red on map). The upperparts are greyer and more olivaceous than other races, and the forehead feathers are tipped whitish.

Habitat. The Dark-backed Weaver inhabits forested areas, including riverine and gallery forests in open country, and second-growth forest regenerating after shifting cultivation, coffee forests, denser patches in dry baobab woodland, and in South Africa dry Valley Bushveld. It joins mixed-species flocks of insectivorous birds.

Food. Food items are mostly arthropods, including grasshoppers, beetles, caterpillars, bugs, flies and spiders. Other food items are berries, fruit, and nectar. This species forages in the tree canopy and at the leafy ends of branches.

Dark-backed Weaver
Dark-backed Weaver adult in nest

Breeding. The Dark-backed Weaver is a monogamous, solitary nester, with the pair-bond lasting for several years. The nest is retort-shaped. The entrance is extended into a spout that is usually <30cm long but may be up to 60 cm. The nest looks rough because it is made of stiff materials such as thin vines and creepers. A pair usually nests in the same area each year, so there may be 2-3 nests close together. One nest took 7 days to complete, and another took 9 days. Although nests are often high, and at the end of twigs, snakes do reach them and take young.

Dark-backed Weaver
Dark-backed Weaver courtship

 

Other. The longevity record for Dark-backed Weaver is over 5 years in the wild, but can be expected to be much more (see news item).

The song of the Dark-backed Weaver is often a duet, with the male and female singing the same elements in a nearly simultaneous sequence, after some introductory notes which show increasing synchrony. There are local dialects in this song which appear to remain stable over many years. There are large-scale differences in song between geographically separated populations. The young apparently learn the song from their parents and other adults, and the song type stabilizes within the first two years.

The above is based on Weaver Wednesday, a weekly series about weaver species.
This species text first appeared as Weaver Wednesday [35]: Dark-backed Weaver on 2013-02-13

2. Breeding facts

Pair bond
Monogamous, pair-bond lasting for several years


Breeding season
Nov-Dec on Bioko, Dec-Jan in Cameroon; in DRCongo, Feb-May and Sept-Dec in S and Jan-Feb in Itombwe; Aug-Sept in Somalia; Apr and Aug in Kenya (but Mar-May and Jul-Aug at Kakamega Forest); Dec-Jan in Tanzania; Aug, Oct-Nov and Feb in Angola, Sept-Dec in Zambia, Oct-Mar in Malawi, Sept-Feb in Zimbabwe, Sept-Dec in Mozambique, and Oct-Jan in South Africa


Nest site
supended 2.5-15 m (most often 4.5-6 m) above ground from tip of branch or creeper, often in thorny tree, on Zanzibar also suspended from telephone line


Nest building
Both partners may build nest, usually one member of pair, presumed to be male, does most building while partner perches nearby


Colony size
Solitary nester; pair usually in same area each year, so that two or three nests may be found close together


Clutch size
2-4 eggs (average 3 in South Africa)


Egg colour
pure white, pale blue, pink or greenish-white, sparsely spotted with brown, red and lilac


Egg size
average size of 54 eggs 22.7 x 15.4 mm (South Africa)


Incubation
in captivity, incubation by both sexes, estimated period 15-17 days


Chicks and nestling period
chicks fed by both male and female, nestling period 22 days; fledglings fed occasionally until 6 weeks old


Breeding information based on Handbook of the Birds of the World, Vol. 15.

3. Photos of Weaver Nests


Vm 29295

Vm 28964

Vm 28947

Vm 28556

Vm 28063

Vm 27312

Thumb-nails of recent PHOWN records