Monday, 3 November 2014

Nordic nomads

The first wave of short-eared owl arrivals has already happened; the appearance of birds at various sites along Norfolk’s curving coastline heralds a welcome return. These nomadic wanderers have become a feature of the Norfolk winter, with individuals wintering on many of our coastal marshes and, further inland, along river floodplains and on smaller areas of rough grassland. Being active during daylight hours, these stunning owls always prove a delight for the county’s birdwatchers.

These winter visitors may have come from our own breeding population, found on the uplands and coastal marshes of northern England and Scotland, but others will have crossed the North Sea, arriving from Scandinavia and other parts of northern Europe. Given the distribution of wintering short-eared owls within Britain, with a strong wintering population in northern England, it seems most likely that those wintering in East Anglia will have arrived from overseas, while our breeders winter locally within the northern half of the country. A recent review of the movements made by short-eared owls, undertaken using information collected from bird ringing, has revealed that these birds are now wintering further north than they did just a few decades ago. Since the species is highly nomadic, responding to the availability of its favoured small mammal prey, it may be that a changing climate is allowing them to remain further north than was formerly possible.

That the short-eared owl is now regarded as a winter visitor to Norfolk underlines its loss as a breeding species. Pairs were regularly found breeding around the Wash, on the east coast marshes and inland within the Brecks, all lost over the last 40 years. The individuals present during the winter months will be feeding predominantly on field voles and other small mammals, but small birds are also taken, sometimes from roost. Ringed plover, dunlin, skylark and snipe may all feature in a short-eared owl’s diet.

As winter progresses, many of these newly-arrived short-eared owls will settle on favoured sites and several individuals may be found hunting over the same patch of grazing marsh, often hunting alongside the local barn owls. It is quite a sight to see half a dozen of these enigmatic birds quartering a piece of ground and one well worth connecting with.

No comments:

Post a Comment