Birder’s diary – about identifying white-spotted bluethroats

Birder Margus Ots,
Translation: Liis
In Estonia two subspecies of the bluethroat (Luscinia svecica) can be encountered – the white-spotted bluethroat (Luscinia s. cyanecula) is a rare breeder in willow thickets in water meadows and the red-spotted bluethroat (Luscinia s. svecica) occurs only on migration. The male white-spotted bluethroat usually has a white breast patch (it may also be wholly lacking) and the red-spotted bluethroat has a red breast patch. But in handbooks the issue tends to be over-simplified. In fact the subspecies cannot always be determined by the colour of the breast spot, because the white-spotted bluethroat may also have a red breast spot.
 White-spotted bluethroat (Luscinia svecica cyanecula), male bird with white breast spot (in fact without spot) (22.06.2012 Raadi, photo: Uku Paal)
At Raadi in Tartu a pair of white-spotted bluethroats has been observed over a longer period this year, evidently the species nests here. But on checking it turned out that the male bird had a red breast spot and the question arose as to what subspecies we actually had to do with? To clarify the matter the bird was captured on June 22nd at Raadi. But astonishingly two male birds were captured in the net, one of whom one had a small white breast spot and the other a red breast spot. If the bird with a white breast spot or without any spot at all was a typical white-spotted bluethroat, the specimen with the red breast spot caused some head-scratching.
 White-spotted bluethroat (Luscinia svecica cyanecula), male bird with red breast spot (22.06.2012 Raadi, photo: Uku Paal)
On closer examination it turned out that only the tips of the breast spot feathers were red, on moving the feathers the white colour showed beneath. Thus, this bird too was a white-spotted bluethroat after all. Only recently this identification problem has received more notice and it is indeed true that a part of the white-spotted bluethroats instead can have a red breast spot. Thus it is necessary to be particularly careful with the determination of subspecies of the bluethroat. More specifics about the identification of white-spotted bluethroats are on the Estbirding home page.




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