Wednesday, 26 January 2011

The Rise of the Bittern

The bittern count rose to four today, all seen from the Ivy North hide, at one stage simultaneously. It seems they were likely to be two males and two females, based on the size, males being appreciably larger than females. It might be that these are the only bitterns present on the reserve, but most of the other likely areas are not easily viewable. There are also many other areas along the Avon Valley that are probably suitable for them, at the very least the river gives valuable access to open water in freezing conditions. Of course bitterns are rare birds in Britain, although many of the birds here in winter will be visiting from the continent. These birds are forced to move to avoid freezing conditions and many will come westward where conditions are milder.

There has been a lot of work done to improve habitat for bitterns in Britain, mainly this has involved creating the large reedbeds that they prefer to nest in, but in cold years winter survival can be critical to the fortunes of the population. In winter the seek out shallow lakes with abundant fish, in the past these would have been rare across most of England, but we have made many such sites in the last hundred years or so by gravel digging and other activities. Such places are now a valuable resource for these birds and probably a significant additional factor in the growth of the population in recent years.

Gravel pits are obviously artificial habitats and like other man made habitats, their creation has presented opportunities for a number of species to increase their range or numbers. A site like Blashford also offers opportunities for people to get an experience of wildlife that is hard to achieve on more ancient and sensitive sites. We can provide paths and hides without damaging valuable areas of habitat. This allows people to get better views of species or see ones that otherwise they may never see. Although Blashford may provide important habitat to help bitterns survive the winter, the experience of seeing a bittern might well be every bit as important, helping to build support for the kind of habitat creation work that is leading to their recovery as a breeding species in Britain.

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