A familiar sight in the Blackwater Valley, the Grey Heron can appear almost anywhere, sometimes well away from obvious waterways or lakes. The Heron is a large bird often seen in flight, at first evoking ideas of a big bird of prey until the crooked neck and long trailing legs become evident. It has wide slow-beating wings looking a little ungainly in flight. On the ground the bird is often overlooked as it stands almost motionless waiting to use its dagger-like bill to catch a fish in the water. Many times you can get quite close before the bird flies off, mostly quietly, although a harsh ‘frarnk’ call can be heard if it is suddenly disturbed from its resting or feeding place. Herons, like Little Egrets, can also be found perched in trees.
Despite many walks along the Valley I have never found any heronries and our spring and early summer birds are likely to be non-breeding adults or birds feeding some way from their nests, which is characteristic of the species. Young birds are likely to appear from June onwards leaving their nests after three months of care by the adults. In autumn, numbers increase as a result of dispersal and as winter approaches some immigration occurs from northern Europe. Very few of our Herons have been found to have migrated the other way, into Europe, although some do fly to Ireland especially in hard weather.
The Heron is one of our earliest nesting birds and eggs can be laid from early February, although early March is more common. Generally they are single brooded and lay three to five eggs. They are monogamous for each season unless the breeding attempt is unsuccessful, in which case a further pair bond may be created. Heronries are noisy places and it is rare to find a bird nesting alone, dozens of nests are possible in tall trees but sometimes, such as at Heathlake, a couple of miles north of the river, only two nests may form a heronry.
Herons feed mostly on fish but also take small amphibians, reptiles, worms, insects and plant material. The most likely place to see them in the Valley is by standing water, such as Moor Green Lakes, Frimley Hatches, Tongham Pool and Badshot Lea pond, although they will frequently be encountered in the river itself standing quietly in the hope of finding some of the many fish that thrive there nowadays. It is also worth looking in Hawley Meadows, where they often stand in the wetter areas, sometimes alongside the Little Egrets in winter months. A common bird but one that always adds pleasure to a walk along the Blackwater.
Berkshire Ornithological Club