Birding Column: Sociable Weaver: A Northern Cape Icon

the colony will construct a nest chamber which all face diagonally downwards –standing underneath and looking up is truly a sight to behold.

to roost and breed in.

Driving along any major route in the Northern Cape, one cannot help but be drawn to large, spectacular nests on roadside telephone poles or thorn trees.

These are the communal nests of the sociable weaver (Philetairus socius;Afrikaans: versamelvoël) a species that belongs to the weaver family and only occurs in SouthAfrica, Namibia and Botswana, and nowhere else in the world.

The core of their distribution lies in the Northern Cape and they are a bird associated with arid or semi-arid landscapes.The species is not threatened and is generally common, and abundant throughout its range.

The Gariep Bird Club, based in Kimberley, has chosen the sociable weaver as its logo, representing the Northern Cape, the arid environment in which we live and the social nature of birds, birders and people.

It builds one of the most spectacular communal nests of any species, which has a magnificent structure.

Colonies can number anything up to 500 birds and each pair in

Colonies can be up to 4 m deep, 7 m in diameter and weighing up to 1 ton. Birds use dry grass straws to build their nest chambers, which structures the size and shape of the colony; some nests are known to be over 100 years old. Breeding is associated with rainfall and as such they may breed for eight to nine months of the year The number of eggs laid varies, based on the amount of rain.

They are able to adjust the clutch size to environmental factors to maximise the survival of the chicks.Three to four eggs are usually laid. Interestingly, these birds are cooperative breeders with “helpers” – non-breeding adults – that assist in raising the chicks and keeping the nest and chambers well-maintained.

The Pygmy Falcon,Africa’s smallest raptor, has a close relationship with sociable weaver colonies and pairs utilise an unoccupied chamber

Due to it being abundant, living in large social groups and surviving in dry, arid environments, the species has been well-studied by researchers and scientists.

At the Benfontein Game Farm outside Kimberley, a long-term project coordinated by the University of CapeTown (UCT) is looking at understanding how social and environmental factors influence long-term changes in sociable weaver populations.

It is a species that will no doubt respond to changing climates and landscapes, and we are certainly learning a lot about how these birds adapt and change their behaviour

Visit the Benfontein Sociable Weaver Project at sociableweaverproject.com and the SouthernAfrican BirdAtlas Project at sabap2.birdmap.africa.

Written by Dr Doug Harebottle, chair of the Gariep Bird Club

Contact the club at birdclubgariep@gmail.comNoord Kaap Bulletin