19 APRIL 1946, Page 16

Semi - Liberty

The ingenious little Avicultural Magazine, edited by Miss Barclay- Smith (of the Zoo, if I may say so), is making play with a more or less new term. It has issued a special " semi-liberty number " (price 5s.) which is full of pleasant stories of tame birds, especially one of a jackdaw that could be taken for a walk like a dog. _ A good idea is that captive soft-billed birds should be let free from their aviaries during the spring and early summer while they are feeding the young. In this way they will not be tempted to wander, will do the maximum of good and save their owners from the extremely difficult task of finding enough of the right carnal food for the chicks. My own only experience of semi-liberty was concerned with the thrush that the Americans call a robin. It flourished and built and bred in the wild ; but vanished completely without trace at migration time in the autumn. It is, I think, a wrong thing to cage any bird with a strong migratory instinct. I knew, for example, of a caged cuckoo that would fall into a sort of coma in August and spend hours in an automatic pulsation of the wings. His spirit was on the way to the Caucasus.