Thursday 31 January 2013

Common Birds: the case of the Baglafecht Weaver and missing forests

Male Baglafecht Weaver, Mt Kilimanjaro

 If you live on or near an East African mountain, you're very likely to have Baglafecht Weavers in your garden. Like most of the other true weavers, they're a basic black and yellow colour. The first thing to look at in weavers is usually the colour of the eyes and legs: in Baglafecht weavers you'll always see a yellow eye (easy to see against the surrounding black feathers) and pink legs. Males and females differ slightly: males in the population in northern Tanzania and Kenya have only a black mask on the face, with yellow on the top of the head right down to the (black) beak. Females have an all dark head. In northern Tanzania the back of both sexes is essentially black, with some yellow wing edges, in other areas of Tanzania the back is greenish/grey and not as strongly contrasting. Juveniles of all forms are rather greener and lacking in black, but still have the yellow eye. Like other weavers, they weave their nests from grasses in colonies of 5-15 pairs (not usually in very large groups) and males in the breeding season are pretty noisy with their rather scratchy and squeeky song!
Baglafecht weaver nests aren't the neatest of affairs...

Wednesday 23 January 2013

Common birds: Ring-necked Dove

Ring-necked Dove (Cape Turtle Dove) in Tarangire, photo from here
Two more challenges have been set since the last one, and I'm hoping to rise to each! The first was for the African Collared Dove, however that species (Streptopelia roseogrisea) from the drier north of Africa in the Sahel and in the Middle East is not found in Eastern or Southern Africa and I suspect request was for a Ring-necked Dove Streptopelia capicola which is indeed one of the commonest birds to be seen in the bush across much of Africa.

The sound of the Ring-necked Dove  is one of the constant backgrounds to a safari in the bush (if you don't know it, the "work harder, drink lager" refrain is available here) and it's actually this distinctive song that is the easiest way to identify the species from among a number of confusingly similar species. The ring-necked dove is a medium sized, grey dove. It has a black collar around the back of its neck and is a paler grey white below, with pale edges to its tail. Unfortunately, that description is would cover just about any of the close relatives of this species, and (as well as listening to the calls) you need to look rather closer to identify the species correctly. Firstly, look at the eye: if it is dark and not obviously surrounded by bare skin, you're probably looking at a Ring-necked Dove. White (not grey) edges to the tail and a generally pale grey would confirm the identity in eastern and southern Africa. If the eye is pale yellowish, with a red ring around it and there's a warmer brownish wash to the back and neck that contrasts with a grey head, you're probably looking at an African Mourning Dove (call) and if its got a dark eye in a bare purple/red patch of skin, and is overall darker looking, with grey tail edges, you're looking at a Red-eyed Dove (call: "I am a Red-eyed Dove").

Sunday 6 January 2013

Common Bulbul and frugivorous birds

Common Bulbul nesting in Arusha
Thanks to doubtful comments from a colleague, next up in the common bird series is going to be the Common Bulbul. These birds are probably the most widespread birds in Tanzania and should be a familiar sight to everyone, with their dark blackish heads, brown back and tail, and dirty white underparts with yellow under the tail. They're typical garden birds, and often ignored. However, it is often the common birds that we know most about, because they are so easy to study. And common species, simply because there are so many individuals, often have a very irritant role to play in ecosystems - the common bulbul is no exception!