XXXVII 

 VARYING FECUNDITY IN BIRDS 



Why some eggs are all red, as the Kestrils ; some only red at one end,[as those of Kites and 

 Buzzards ? why some eggs are not Oval but Round, as those of fishes ? etc., are problems, whose 

 decisions would too much enlarge this discourse. SIR THOMAS BROWNE. 



I record and if possible explain variant 



'T^HE ordinary bird's-nester , whether clutches . 



scientific or merely predatory, There are a few general principles 



plunges greedy fingers into abnormal it is well to keep in mind in pursuing 



clutches of eggs, large or small, this branch of bird-study. Such is 



regarding only their suitability for his the rule that birds do not merely breed 



incomplete collection. He robs a so many times in the year to satisfy 



nightingale of six eggs, a partridge of a periodical sexual desire, nor even 



fifteen, without desiring or attempting to tickle parental instincts. Their 



to explain why the offspring of the nature would appear to be unsatisfied 



one is numerically so superior. Some with any partial fulfilment of the 



years ago, reviewing my season's propagating and rearing functions. It 



" take " of eggs, I felt myself some- is young, not eggs, that they require 



what of a monster when I imagined in the first place ; and in the second, 



the table on which my cases lay, as they must bring a certain number of 



peopled with the developed embryos nestlings to maturity, if the fates and 



each shell had once contained six the season allow. Compare them with 



nightingales, a dozen bullfinches, and a domestic cat. The female may be 



so on ; although I had never in my perpetually running with a male. She 



life taken more than one egg from the accepts the consequent kittens in either 



same nest. Consequently in aban- a philosophic or maternal attitude, 



doning egg-collection, I sought for a according to her temperament; but 



new interest in eggs to take its place, whatever her temperament, if the 



Without an interest in eggs as distinct kittens are relentlessly drowned in 



from birds woodcraft must depre- their infancy, she will not kitten again 



ciate, since the finding of the actual for six months or so. The nightingale 



nest would cease to be necessary, takes parentage far more seriously. 



And the necessary interest gradually Harry a nightingale's nest when the 



developed in the form of a desire to fledglings are almost ready to fly. The 



