Monday, March 7, 2011

The morning bird census was all about Corvid passage today. There was a small movement of Raven, but the highlight came in the form of a Hooded Crow which fed with Carrion Crows around the Narrows. As with all Hooded Crows of recent years, this individual proved particularly skittish and was far less confiding than the Carrions it was hanging around with. Hooded Crows are rare in Wales but a few birds have frequented Anglesey recently.

This appears to be a pure Hooded Crow, not showing the extra black areas typical of a Carrion Crow x Hooded Crow hybrid.© Richard Brown

Also of note were at least three male Stonechats. Once a common breeder on the island, breeding numbers have rapidly declined over the past ten years to just one breeding pair in 2010. The pair was successful however, and fledged ten young in three broods. The exact causes of the decline are unclear, but recent harsh winters will have played a major role. Unlike many resident, insectivorous birds, Stonechats rely heavily on invertebrates during the winter and do not turn to fruits and grains for survival.

Male Stonechat © Richard Brown

The remainder of the day was spent repairing the Heligoland Trap in the Obs Garden, which took a battering through the winter. In the last couple of years the trap has caught species such as Ring-necked Parakeet, Wryneck, Subalpine Warbler, Melodious Warbler and Marsh Warbler along with hundreds of commoner migrants, so it was important to fill the gaps where birds were escaping from.

The Heligoland Trap in the Obs back garden. The trap is basically a funnel which directs birds to a trapping area at the end, where our trained staff can collect the birds from a small trap-doored box. The trap was first used on the German island of Heligoland in the early twentieth century. © Giselle Eagle

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