Eerstejaars Boomvalk Falco subbuteo in de netten

On 8 September 2008, a first-year Hobby was captured whilst netting Bam Swallows. Presumably the same bird had been present at this CES site in the central Netherlands since 15 June. Given the measurements (flattened and straightened wing 252 mm, 8th primary 170 mm, maximal tarsus width 4.5 mm and body mass 193 g), the bird was assumed to be a male. The bird was not in active moult, but had recently replaced a number of body feathers and remiges. In the right wing, primary 4 (with its matching primary covert) had been renewed, as was secondary 5. In the left wing, primaries 4 and 5 had been replaced (with matching primary coverts), as well as secondary 5. Buff edges to coverts and flight feathers, typical of juveniles, were not visible anymore, presumably because of wear since fledging. A number of contour feathers had also been moulted, clearly visible amidst the more brownish unmoulted feathers. The undertail coverts were ochre-coloured (juvenile), rather than red (adult). The cheeks were white, but the throat had retained some ochre-coloured feathers from the juvenile plumage. The forehead was lightly streaked.