7 SEPTEMBER 1945, Page 14

Altruistic Blackbirds

The oddity of a robin building in a blackbird's nest was recorded last week. This week by accident I came upon the following passage in Trevelyan's Life of Lord Grey: "There are robin's eggs in the alcove nest, of which the foundation and outside is blackbird, the middle wagtail, and the inside and top now robin-built.' I suppose blackbirds' nests are popular because they are so gloriously and superlatively solid. Tits will sometimes carry off the superfluous moss,_and bumble-bees are fond of the old nests. As to contiguous nests, my own bdt-on-record, made in company with F. C. Selous, was a tit's nest in a box, a thrush's on the lid, and a tree-creeper's behind, in a fold of the oak-bark. That was in a Surrey park.