94 ON THE NATURAL HISTORY OF THE NIGHTINGALE. 



he has " frequently seen the Nightingale in October, and once in 

 November." This species, in a state of captivity, as is the case 

 with those other of our migrant songsters which do not undergo a 

 moulting in the spring, usually begin to sing about Christmas, or a 

 little after ; so that, if it ever do continue in this country through 

 the whole winter, it is difficult to conceive how its melody should 

 escape notice during the earlier months of the year r certainly, in 

 the cage, it never sings more delightfully than at this period. 



The males of most migratory birds arrive sooner, and depart later 

 in the season, than the other sex. — It is all but an universal law 

 among migratory land birds, for the male to arrive several days 

 before the other sex, and to depart later in the autumn : in other 

 words, male birds would appear, in general, to be more susceptible 

 of the influence of heat, and female birds of that of cold. Not that 

 I consider that change of temperature is, by any means, the ulti- 

 mate cause of birds seasonably shifting their habitations, nor is it, 

 in all cases, even an element in the mystery, for the Swift and the 

 adult Cuckoo retire southward at the very hottest period of the 

 year, and when their food, also, is apparently most abundant. 

 Still it is a predisposing cause, which tends to increase the force — 

 and to accelerate the period — of that periodical migrative impulse 

 which would certainly be evinced in due time, even were the tem- 

 perature to continue the same ; as the above-named cases of certain 

 species leaving us during the heats of summer attest sufficiently. 



Supposed cause of this. — Male birds appear for the most part to 

 be considerably more lively, and sprightly, than their mates, fonder 

 of exposing themselves in the sunshine, and may possibly, on this 

 account, be sooner affected by the influence of that luminary ; while 

 the females, on the other hand, are in general much more hidling 

 in their habits, and living more in the shade, may probably, for this 

 reason, be sooner chilled by the cold air of autumn, and more tar- 

 dily excited by the genial influence of a vernal sun, than if they 

 kept less to the covert. It is a fact extremely well known to bird- 

 catchers and others, that the arrival of the male Nightingale pre- 

 cedes invariably that of the other sex by full ten days or a fort- 

 night ; and they cease to capture them from the period when the 

 hen birds first make their appearance. 



The Nightingales period and time of singing. — The bursting 

 forth of this species into full song is affected chiefly by the weather, 

 for they very much dislike cold winds, though they seem to be quite 

 indifferent about rain : if the weather prove favourable, they sing 

 cut immediately on their arrival in the woods. Then if the tim« 



