SMALL BIRDS’ DIET

Wairarapa Times-Age, 18 October 1939, Page 6

SMALL BIRDS’ DIET

INSECTS AND WEED-SEEDS. Captain E. V. Sanderson, president of the Forest and Bird Protection Society, states that the campaigns of county councils in Canterbury against small birds are another reminder of the need of a proper study of the habits of the imported birds, and a thorough understanding of their place in nature, so that the earth may continue to be habitable by man. He says that no proper investigation of that matter has yet been undertaken in New Zealand, and that unless there guidance in this field, there is always the possibility of serious blunders in wars of extermination against certain introduced species of small birds.

In a well-known book, “The Practical Value of Birds,” Junius Henderson, Professor of Natural History at the University of Colorado, gave the world some very helpful information about the economic value of some much-persecuted species of small birds. Here arc some passages in which New Zealanders should be interested: — • “The great slaughter of wild birds and the destruction of from 80,000.000 to 100,000,000 of their eggs annually in France for some time resulted in the poor crops of 1861 because of the increase of insects, and the summer following a great bird drive near Bridgewater. Massachusetts, the trees in the nieghbourhood were defoliated by insects.” “The majority of seed-eating birds crack the weed seeds or grind them, and thus destroy large quantities of highly-injurious kinds, doing much good in that way. In a patch of smartweed a space of 18 inches square was carefully examined, and 1130 cracked seeds were found, with only two whole seeds. In late May pracdca. Jy no seeds were left in the patch. It has been estimated by the United States Biological Survey that the various species of sparrows alone saved the farmers 89,260,000 dollars in 1910 by the destruction of weed seeds. “A single plant of one of these species may mature as many as one hundred thousand seeds in a season, and if unchecked would produce in the spring of the third year ten billion plants. Sparrows and juncoes so thoroughly cleaned out the seeds from a big tangle of smartweed on a Maryland farm that none of the weeds appeared during the following year. "The finch family, the largest family of birds, including sparrows of many species, grosbeaks, crossbills, and their allies, are pre-eminently seed-eaters, having bills especially adapted to the cracking of the seeds of various weeds. This is well exemplified in the canary. An examination of 4000 stomachs of native North American finches and sparrows of various species showed that during the colder half of the year their food consists almost entirely of weed seeds.”