2 JANUARY 1932, Page 18

* * * * LEGITIMATE TRAPS.

One sort of trapping is practised much more in America than in any country, especially by the students of bird migra- tion. Instead of ringing nestlings, though this also is done, all sort of birds are " caught up," even birds as big as wild geese, and released as soon as ringed. One of the troubles of the method is that the local birds keep returning to the traps ; and the statistics of refusal to migrate must exceed statistics of long-distance migration ! The habit is growing in England, but the traps are almost exclusively set for very small birds. It was astonishing—in one small garden in the Midlands—how many of the lesser migrants, mostly willow warblers, were thus trapped last autumn. Personally, I think, the ringing of the very small birds much over-done, and fear that, light though the rings are, they may increase the danger of the migratory flight.