NESTING BIRDS

Evening Post, Volume CIX, Issue 40, 15 August 1925, Page 16

NESTING BIRDS

CO-OPERATIVE FAMILIES.

Most -of us who take an interest in bird life have found many departures from the normal in the economy of nesting birds, writes Captain C. W. R. Knight, M.C., in the "Daily Mail." It is not unusual, for instance, to find a pair of birds occupying a deserted nest, and I recall an instance of a pair of great-tits which were nesting in an old thrush's nest. I have on several occasions found _ a wild duck sitting on her eggs in a disused crow's nest built among the upper branches of a tallish tree. This will come as a surprise to those of us who were not aware that ducks quite commonly nest in trees. It is curious that the ducklings—little balls of downtumble from the nest to the ground and run off without, apparently, the least inconvenience.

Then one sometimes finds that a new nest is built on top of one already in existence. I remember discovering such a double reed-warbler's nest, the "builtover" portion containing eggs as well as the new extension. What a haul for the egg-collector! Again, one not infrequently finds that two hen birds of different species are laying their eggr —either of choice or necessity—in thi> same nest. The more aggressive—or morejoersistent—female is left in charge to hatch, and perhaps to rear, the young. The other retires to some more secluded spot. The most curious case that ever came under my notice—and as far as I know that has ever been recorded—was that in which a pair of robins and a pair of wagtails co-operated. The females took turns in brooding the eggs, and on one occasion at least we actually saw both birds brooding at the same time. At this stage the nest contained eight nggs --four each of robin and .wagtail. Later,nil four parent birds worked, hard' In keep tliPin supplied, and I look nrnn«rous photographs of them as, in I urn, fliov visited the nest wi'Mi food which they '.lirlributed indiscriminately among the family.