Weaver species

Choose different species from drop-down list and press 'Go' button. See Full species list.

Sociable Weaver Philetairus socius

IUCN: Least concern     Discovery: 020

Categories: cooperative, acacias, fruit, gum, Gymnogene, Nest use, Pseudonigrita+Philetairus,
News items about species

Discovery

Sociable Weaver
Sociable Weaver,
figure from Paterson 1789
Sociable Weaver
Sociable Weaver nest,
figure from Paterson 1789
Sociable Weaver map
Sociable Weaver
distribution, type locality circled

Introduction

The Sociable Weaver was formally described by John Latham, a Scottish explorer. Latham based the details on a travel book by William Paterson, a Scottish soldier and explorer. Paterson was sent to the Cape Colony to collect plants, and he made four trips into the interior between May 1777 and March 1780. In his published narrative, he wrote mostly about plants and rarely about animals. However, on his journey to the Orange River in 1779, he described a giraffe and the Sociable Weaver.

Paterson provided the first description and illustrations of the Sociable Weaver and its massive communal nest. He compared the nest to a thatched roof which he considered an "aerial city". He saw many large nests and estimated one to have 800-1000 birds living in it.

Paterson wrote about the Sociable Weaver in December 1779 after having returned from Namibia, so the exact locality is not clear. He noted that he saw the weavers and nests soon after seeing giraffe, and he would have seen the nests north of the Orange River between Goodhouse and Warmbad, during October 1779. The type locality was restricted to Warmbad for convenience.

Soon after Paterson's journey, Le Vaillant travelled to the Orange River and also illustrated and wrote about the Sociable Weaver. He collected the first Rosy-faced Lovebirds, which he obtained at a Sociable Weaver colony. Le Vaillant thus was the first person to report weaver nests being used by non-weavers. Thereafter, many travellers in southern Africa wrote about the Sociable Weaver and its unique nest.

Scientific citation

Loxia socia Latham 1790 Index Ornith., vol. i, p.381 Capitis Bonae Spei interioribus [=Inland of Cape of Good Hope], restricted to Warmbad, southern Great Namaqualand, Namibia, by MacDonald 1957.

Meaning of names

socius (Latin): sharing, allied [ie sociable].

First English name

Social Grosbeak (Paterson 1789)

Alternate names

Republican Grosbeak, Sociable Grosbeak, Social Weaver.

Collector

William Paterson.

Date collected

October 1779.

Locality collected

Capitis Bonae Spei interioribus [=Inland of Cape of Good Hope], restricted to Warmbad, Namibia.

Type specimens

Type specimen not known to exist; the illustration of Paterson 1789 serves as a type.

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 [137] - Discovery [20]: Sociable Weaver on 2015-01-28

1. Basic biology

Identification. The Sociable Weaver Philetairus socius with its huge communal nest is the iconic feature of arid regions in southern Africa. Adults are distinctive with scaled upperparts and flanks, black bib and brown cap. Juveniles lack the bib.

Distribution. The distribution map (below) is based on The Atlas of southern African Birds, showing the current PHOWN records. There have been very slight range expansions at the edges of its range in some parts (e.g. see here), although the southernmost colony has not changed in 21 years (e.g. see here).

The Sociable Weaver is expected to expand its range as climate change results in an expansion of the arid region in southern Africa. Several subspecies have been described for this species in the past, but are no longer considered valid.

Habitat. This species is found in open, arid country with scattered trees.

Food. It forages on the ground, feeding on seeds and insects, especially harvester termites. They forage within 1.5 km of their nest sites which they occupy year-round.

Breeding. The nest of the Sociable Weaver is remarkable. It may be the largest nest in the avian world, although other contenders have been considered. Nests may be up to 7m diameter, with a weight up to 1 ton. The nests are built of dry grass and nest masses would not survive in areas of high rainfall. Birds huddle together in chambers on cold winter nights to raise the temperature within the chamber. During hot summer days, birds shelter in the cool shade of the chambers.

Nest sites are mainly camel thorn trees but other tree species are also used, as is the quiver tree (photo below left, phown 1103). Man-made structures are often used, particularly telephone poles. Interesting nest sites were on a dilapidated rondavel (photo below center, phown 1030) and on windmill blades (photo below right, phown 1577).

Sociable Weaver nests provide shelter and nest sites for many other birds, particularly the Pygmy Falcon which is dependant on this weaver in southern Africa (e.g. see Tswalu survey). Some other species that regularly roost or breed in the Sociable Weaver nests are Acacia Pied Barbet, Rosy-faced Lovebirds and Red-headed Finches see photos here).

Ideally nest records submitted to PHOWN should include a nest count, where possible, to obtain a rough guide to the colony size. For Sociable Weavers, this means counting the individual chambers by walking underneath the nest mass. Presence of snakes, however, is a good reson not to count nest chambers - Cape Cobras often raid eggs and chicks in Sociable Weaver nests, as seen in this photo (left, from phown 2172).

The above is based on Weaver Wednesday, a weekly series about weaver species.
This species text first appeared as Weaver Wednesday [16]: Sociable Weaver on 2012-10-03

2. Breeding facts

Pair bond
Monogamous, but successive nesting attempts often with different partners, even if former mate still present in colony. often breeds co-operatively, with up to nine helpers (both adults and young)
Breeding season
Dec-Aug in N Namibia and Nov-Jan in SE of range; elsewhere breeding not seasonal, dependent on irregular rainfall, continued over 9-month period
Nest site
placed 3.5-7 m above ground in tree such as Acacia erioloba, Acacia haematoxylon, Acacia giraffae, Boscia albitrunca, mopane (Colophospermum mopane) or Aloe dichotoma, occasionally exotic tree utilized, and once nest placed on small cliff; in treeless areas, telephone poles used since 1949 (baskets fitted on pole to avoid nest mass being built around insulators) and recently also electricity pylons (nest usually low, within 4 m of ground)
Nest building
material added throughout year
Colony size
up to several hundred individuals at a single nest; roof over separate nesting chambers (up to 95)
Clutch size
2-6 (mean of 32 clutches 3.6)
Egg colour
dull white, densely spotted with different shades of grey
Egg size
average size of 76 eggs 20.9 x 15.1 mm (South Africa)
Incubation
by both sexes, period 13-14 days
Chicks and nestling period
fed by both parents and by helpers, nestling period 21-24 days

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

3. Photos of Weaver Nests


Vm 26655

Vm 26654

Vm 26620

Vm 26619

Vm 26618

Vm 26523

Thumb-nails of most recent PHOWN records - click on one to see its full record
See all PHOWN records for this species here.

PHOWN (Photos of Weaver Nests) provides valuable info on breeding distribution and colony sizes of weavers.
You can contribute by registering and submitting photos at Virtual Museum webpage.

4. Breeding distribution