Abstract
IF Dr. Long assumes that the 23.9 per cent, of injurious insects left unconsumed might have multiplied, it is surely only fair that he should also assume that, under similar conditions, the 48.5 per cent. of cereals, potatoes, and roots would have multiplied and brought forth a hundredfold. The point at issue, however, is whether, in estimating by the volumetric method the amount of food consumed by the rook per annum the figures express equivalent or economic values. This method has so long been recognised as the only trustworthy one that it is not necessary to reassert its superiority over all others; and as McAtee has so pertinently remarked (The Auk, 1912, p. 452), such “criticisms are wide of the mark, for no one claims that percentages do express economic values. They are simply convenient handles to facts, and they must be interpreted.” As the result of long experience and the examination of the alimentary system of upwards of two thousand rooks, by which we have obtained the percentages referred to, viz. that of the food consumed by the rook during a whole year, 52 per cent. is injurious, 19.5 per cent. neutral, and 28.5 per cent, beneficial, our interpretation of these figures, in the light of a long experience as to the detailed nature of the food under each heading, leads us to the conclusion that this bird does considerably more harm than good.
Article PDF
Rights and permissions
About this article
Cite this article
The Food of the Rook. Nature 101, 304 (1918). https://doi.org/10.1038/101304b0
Issue Date:
DOI: https://doi.org/10.1038/101304b0
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.