Thursday 28 March 2013

Delayed woodcock migration

By the third week in March I would expect to have seen the woodcock leave on their spring migration. On March 21st last spring only one bird remained on my ringing site, the average winter count is around 25 -30.

Wondering if this cold weather might have delayed migration I went out on Tuesday night to have a look. With clear skies and full moon this was just a counting excercise because catching with such high levels of light is almost impossible.

The temperature was well below freezing and there was a fresh N E wind blowing. Over the 150 acres of the site I counted 30 woodcock, so it looks like they have delayed migration due to the cold weather.

 Each March I notice that average weights rise as birds put on bulk before migration. Although woodcock seem to hold their weight well through periods of moderate frost, as they appear to adapt their feeding regime to daytime finding soft patches under leaves and near springs in warmer woodland, I wonder if the reduced possibility of feeding on fields at night has prevented them reaching their optimal migration weight.

Even if the cold was not a problem, the strong easterly headwinds coming across the North Sea may well have halted their migration anyway.

With moonrise becoming later, there will be a chance to get out and catch woodcock again by next weekend. It will be interesting to see how many birds stay on site and what their weights are. The possibility of ringing woodcock in April is amazing.

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