1896.] The Song of Birds. 1 6 1 



agreeable to the females, would tend to become hereditary. Finally, 

 male birds excelling in range of voice would learn new notes from their 

 environment, and develop into more or less accomplished mimics. Mr. 

 Witchell's chapter on the influence of imitation is the part of his book 

 which is likely to be read with most suspense of judgment. It contains 

 some excellent remarks (pp. 192-3) on the difficulty of detecting 

 mimicry— especially when imperfect— and on the general impossibility 

 of subjecting to proof the statements of an observer who claims to have 

 heard particular imitations. No one with the least susceptibility to Mr. 

 Witchell's evident love of nature would question for a moment the strict 

 fidelity of his record— so far, that is, as his observations can be severed 

 from his inferences. But are casual resemblances so rare among natural 

 sounds that mimicry may fairly be inferred or conjectured when a heron 

 (p. 182) croaks like a frog (N.B.— the dead heron does this automatically) ; 

 or a landrail (p. 189) salutes his bride in measured tones attuned like 

 munches of a grazing cow .^ The suggestion by the way of the proximity 

 of the latter kind of animal would be a bit disquieting to the sitting 

 female, and a display of doubtful tact on her mate's part. The following 

 rendering of a thrush's song, in which '* a phrase without recognizable 

 mimicry is indicated by an ' 0' " will serve as a sample of Mr. Witchell's 

 readiness in detecting what he deems imitative resemblances: — "Frocester, 

 Glos., near the church, 17th May, 1892. Thrush singing : — Golden plover 

 — golden plover — O — crow— corncrake — be quick — O — O — wood warbler's 

 sibilous notes — cuckoo (in rough tones) — O — young starling's cry after 

 leaving nest— O— butcher-bird — be quick— O—O—whitethroat's alarm- 

 great tit (cry) — O — O — end" (pp. 203-4.) 



That a few strains are here somewhat too willingly classed as imitations 

 cannot, indeed, be proved but it can be fairly surmised. Sometimes, 

 certainly, Mr. Witchell does make too much of mere similarities between 

 sounds. For instance, the resemblance of the wren's to the hedge- 

 sparrow's song is quite superficial, and requires no such hypothesis as 

 Mr. Witchell offers in explanation,— viz., that both were " derived from 

 some persistent source " (p. 191) — as an alternative to the utterly absurd 

 idea that one of these birds copied the other. The remark, too, that 

 robins, even in winter, often " reproduce exactly " the unique and beauti- 

 ful song of the willow- warbler (p. 207) is startlingly questionable, though 

 here again a slight similarity in cadence is frequently noticed. And 

 surely it was riding a hobby to death to hint (p. 187) that the yellow- 

 hammer's song is a mimicry of the grasshopper's, when on a previous 

 page (p. 48) the same well-known melody had been grouped among those 

 inferior efforts which are obviously " more or less repetitions of the call- 

 note " C. B. M. 



