THIS autumn there is a bumper crop of acorns and walking under a mature oak we find ourselves crunching underfoot dozens of the thousands of acorns littering the ground below.
The oak is truly a most bountiful tree, an essential link in the ecosystem directly or indirectly supporting a vast range of animals, birds, plants, fungi and lichens, all relying on the tree for food and shelter. Some of the most familiar birds of oak woods include all members of the tit family, woodpeckers (pictured), tawny owls, nuthatches and tree creepers, many of which feed on acorns.
The jay, another woodland bird, buries acorns and whilst remembering where they have cached most of them, any forgotten may later grow into small oak woods.
Deer and squirrels consume vast numbers of acorns too. More insects derive sustenance from the oak than any other tree species. Surprisingly, only one butterfly, namely the purple hairstreak, lays eggs on oak leaves, but many moths do so.
If we stand under an oak in early spring on a windless day, we can hear what sounds like raindrops falling onto the leaf litter, but those ‘raindrops’ are in fact the droppings of millions of tiny moth larvae feeding on the foliage! So vast is the number of caterpillars that blue tits time the hatching of their broods to coincide with the wealth of larvae available.
The common or pedunculate oak arrived in Britain about seven thousand years ago and formed the ‘wildwood’ that clothed our country in prehistoric times.