PHOWN time 

The most interesting family in the Passerines is the Weavers, the Ploceidae. They find their mates in a variety of ways. Some feed on insects and others on seeds. Some species breed in massive colonies, and some breed in monogamous pairs which defend territories. The family includes the Sociable Weaver with its massive nests, and the Red-billed Quelea, Africa's "feathered locust." At the other extreme are several species in threat categories. There are species which breed in forest, in woodland and in grassland habitats.

There are 117 species of weavers, and all except five are endemic to Africa. So here we have a biologically fascinating family, occurring almost exclusively in Africa; this has to be this continent's big ornithological research opportunity. Dieter Oschadleus is the ADU's resident ploceidologist. He is the instigator of the weaver website, with URL weavers.adu.org.za.

One of the projects that Dieter has initiated is called PHOWN, which stands for PHOtos of Weaver Nests. It uses the ADU's Virtual Museum platform, and is building up a fascinating visual database of photographs of weaver nests. Having the image, and not only a description in words and numbers on a nest record card, makes a huge difference to understanding the context of a breeding colony or nest. You can read up about PHOWN and what it has already achieved on the PHOWN section of the weaver website. Already the project has better data on, for example, colony sizes than in any of the published literature or handbooks. Through having vast numbers of records of weaver nests of a species, we steadily build up the breeding range of the species (whereas a project such as SABAP2 builds up the overall range of the species, which includes regions where the species does not breed).

Right now, the weaver breeding season is getting underway throughout the summer rainfall region of southern Africa. We invite all our citizen scientists to get their digital cameras to work, take photos of nests – follow the instructions for participation – and upload your records into the virtual museum for PHOWN.

The PHOWN database has data for 59 species, from 27 countries. The country most recently added to the list is Lesotho – in the past few days, Wayne Jones has submitted two records of Southern Masked Weavers. The record that illustrates this news item shows nesting on transmission pylons, and the other record shows a colony with the nests attached directly to electricity cables. You can read up about them here. Nesting on on these kinds of structures, as well as on fences, has enabled several weaver species to expand their ranges into habitats where no suitable natural breeding habitat occurs. The Red-billed Quelea presents "food security" problems; the bunch of species which breed on electricity pylons present "energy security" problems, because the nests cause short circuits, and the resulting "outages" can cause whole districts to be without electricity. The bottom line is that weavers are fascinating and important, from a whole bunch of different perspectives.

Les Underhill
2012-10-02

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