Whilst not uncommon in Dorset the grey heron (Ardea cinerea) is not a numerous species here; it is widespread in small numbers across much of the southern part of the county. It may be that sites from inland and further north are less watched and therefore grey heron are less recorded but it is more likely that this part of Dorset is just not the sort of habitat that suits them. A hundred or so pairs of grey heron nest in Dorset each year in about eight colonies which are surveyed every year and the figures obtained show the grey heron as a declining species. One of these heronries is on Brownsea Island and they are known to be heavy predators of the tern colony and sandwich terns in particular have suffered although measures have been taken to reduce this with some success and the terns have benefited as a result.
In summer months they are likely to be seen near these breeding sites but out of the breeding season they spread out to coastal marshes, along rivers and to the margins of large lakes. They also make themselves unpopular by taking an interest in garden ponds in urban areas. In the autumn and winter the birds from the nesting colonies spread out across the county, mainly to coastal sites (Christchurch Harbour, Poole Harbour, Lodmore, Radipole, the Fleet and so on) but they also go to some inland lakes and rivers and you can encounter them just about anywhere there is water. They stand motionless, like a statue, up to their knees in water waiting for a fish to swim by. Sometimes they prowl slowly around to disturb unsuspecting prey. On cold days they stand hunched up and looking really bad tempered. There are reports of grey heron in just about every week of the year as you would expect in a resident species but the number of reports is greater in autumn as they spread out away from their nesting sites and there are occasional peaks and it is likely that in harsh weather there is a small influx of birds from further north coming here in search of food.
The distribution map shows quite clearly the predominance of reports from the southern coastal areas of the county but also shows a string of reports from sites along the River Stour as far inland as Sturminster Newton. There is less evidence of presence along the Frome. In winter Ferrybridge and Lodmoor in the Weymouth area seem to attract them but although regularly seen at Radipole there are few reports from there; perhaps they are seen as 'fixtures' and not worth reporting? The same may be true of Longham Lakes near Wimborne.
A visit to Lodmoor in autumn or winter will surely see grey heron added to your Dorset list.
Comments
Post a Comment