Tuesday, 19 July 2011

The most yellow of yellows

I have never been entirely comfortable in the Fens, something that I attribute to growing up within the comforting, verdant growth of the Surrey Weald, with its rich deciduous woodland and shortened horizons. There is just so much sky in the Fens, a great expanse of space that stretches on above; it is this that makes me feel exposed. The Fens are, however, part of my annual calendar, a place to visit in winter for the herds of swans and in the summer for Corn Buntings, Barn Owls and Yellow Wagtails.

It is a Yellow Wagtail that has caught my eye this morning; a sharp flight call alerting me to this cracking summer visitor. These arable lands, with their rich soils and dividing lodes and ditches, seem to suit this bird and here, just inland from the Lincolnshire coast, is one of their remaining strongholds. The Yellow Wagtail Motacilla flava has a massive breeding range, one that extends east across Europe and into Russia to reach Alaska beyond. Many different races occur across this huge breeding range, with ours the most striking of all; it is Motacilla flava flavissima, the most yellow of yellows.

Yellow Wagtails arrive from late March, with most appearing in April or May and with a few birds straggling in during the first week of June. I sometimes encounter them on passage, stopping over on bits of damp grassland. The breeding grounds tend to be in areas of wet grassland but arable landscapes (and crops) are also used. The drainage of favoured sites may be one reason for the decline in numbers that has been seen here over recent decades. This may not be the whole of the story, however, because there has also been a contraction in the breeding range, with the species disappearing from much of the southwest and north of Britain.

I see several Yellow Wagtails during the course of the day, with some carrying food into suitable nesting cover. These are wary birds, the adults feeding the young rapidly to avoid attracting unwanted attention to the nest. A calling pair, alarming with the characteristic sree sripp sripp a sure sign that there is a nest with young nearby. I sometimes get calls and emails from observers convinced they have seen a Yellow Wagtail in their garden. Many of these calls come in the winter, when the Yellow Wagtails will be on their wintering grounds in Africa. What these observers have seen will be a Grey Wagtail, a species that not only breeds across Norfolk but may also winter here. While Grey Wagtails do sport some yellow on their plumage, it does not compare to the resplendent tones of an adult Yellow Wagtail.

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