Birds and Galls
Birds and galls
A couple of weeks ago, we were amused to watch the local blackbirds enjoying the rowan berries in our garden. Each bird seemed to have its own picking style. One stood on the fence below the lower branches and leapt up, neatly snipped off one berry, and returned to perch, whereas another crash-landed among the thickest clusters and, wildly flapping to keep its balance, tore off the fruit, stalks and all.
There seems to be a rich crop of wild fruits this year: rowans and hawthorns are laden and the woodland floors crunch with fallen acorns and beech mast. Perhaps that’s why the garden birds are rather sparse at present – there’s a feast for them in the fields and woods. However, numbers will build up. Our blackbirds and thrushes have already been joined by incomers from the continent, and now the redwings and fieldfares are arriving. These are also members of the thrush family, which breed in northern Europe and move south for the winter in great flocks that you may see feeding on the ground in fields, or plundering the berries in hedgerows, parks and gardens. The larger fieldfares with their blue-grey heads and orangey-buff breasts darkly-spotted and streaked, are handsome birds, and noisy too, so you’ll probably hear their loud chackering calls before you see them. Redwings, smallest of the thrush family, have a distinctive white eyebrow and that flush of russet along the flank which gives them their name. At this time of the year they move under cover of darkness. Choose a clear frosty nights and you might hear their eerie whistling contact calls as they fly in huge flocks at heights of 300 metres above your head.
After the recent storms we were puzzled to find our garden liberally sprinkled with pale green disks, the size and shape of lentils. We noticed lots more on roads and pavements around the town, and all under or near mature oak trees. What could they be? Further enquiries revealed the answer. They’re galls formed by the larvae of tiny wasps, which lay their eggs on oak leaves. The galls form as the larvae emerge and start to feed. The leaves fall and the larvae pupate in the leaf litter to emerge as adult females in the spring. Apparently this year the oaks have been quite heavily infested hence the noticeable quantities of fallen galls.
