During the autumn I saw the Lesser Blue-eared Starlings reduce in number, with a single bird on October 22nd and no birds after that. This was expected, because Nikolaus describes the species as a visitor to Khartoum from late July until October (though in Cave and MacDonald, 1955, it is only listed as being found in Sennar and the Nuba Mountains!).
However, I thought the Greater Blue-eared Starling was supposed to be a resident here. They also declined in numbers and I saw my last one on October 29th (at least that is the last record in my notebooks and I may have seen them casually after this date). I saw one today beside the Blue Nile, while I was not birding. I wonder if a few hang around, but most leave. I will try and monitor them more closely and try and find a pattern. If anyone has any observations to add, they would be welcome.
However, I thought the Greater Blue-eared Starling was supposed to be a resident here. They also declined in numbers and I saw my last one on October 29th (at least that is the last record in my notebooks and I may have seen them casually after this date). I saw one today beside the Blue Nile, while I was not birding. I wonder if a few hang around, but most leave. I will try and monitor them more closely and try and find a pattern. If anyone has any observations to add, they would be welcome.
Young Greater Blue-eared Starling, Blue Nile 12 Aug 2010
I normally bird North of the Sahara (in Libya) but I took a birding holiday to Senegal where I saw both lesser and great blue eared glossy starling.Until your post today I hadn't realised that they can migrate. Why? I cant believe Khartoum has less food for them in "winter".
ReplyDeleteYes its odd. Its not as if they are escaping the Arctic winters. There may be some added pressure from the arrival of large numbers of Palearctic migrants also searching for food, but that would also apply to the areas they move to further south. When I was living in El Salvador we would see the Yellow-green Vireos leave in the autumn to be replaced by other vireo species from the US and Canada. Maybe in cases like these there is some other reason they move such as the loss of their main food source. In the UK the Robins leave to be replaced by other Robins from mainland Europe. They all feed on the same things, so this would not be the reason and it is probably to avoid competition.
ReplyDelete