SELBORNE, _Dec. 20th_, 1770.
Dear Sir,--The birds that I took for aberdavines were reed-sparrows
(_Passeres torquati_).
There are doubtless many home internal migrations within this kingdom
that want to be better understood: witness those vast flocks of
hen-chaffinches that appear with us in the winter without hardly any
cocks among them. Now was there a due proportion of each sex, it should
seem very improbable that any one district should produce such numbers of
these little birds; and much more when only one-half of the species
appears; therefore we may conclude that the _Fringilloe coelebes_, for
some good purposes, have a peculiar migration of their own in which the
sexes part. Nor should it seem so wonderful that the intercourse of
sexes in this species of bird should be interrupted in winter; since in
many animals, and particularly in bucks and does, the sexes herd
separately, except at the season when commerce is necessary for the
continuance of the breed. For this matter of the chaffinches see "Fauna
Suecica," p. 58, and "Systema Naturae," p. 318. I see every winter vast
flights of hen-chaffinches, but none of cocks.
Your method of accounting for the periodical motions of the British
singing birds, or birds of flight, is a very probable one; since the
matter of food is a great regulator of the actions and proceedings of the
brute creation; there is but one that can be set in competition with it,
and that is love. But I cannot quite acquiesce with you in one
circumstance when you advance that, "when they have thus feasted, they
again separate into small parties of five or six, and get the best fare
they can within a certain district, having no inducement to go in quest
of fresh turned earth." Now if you mean that the business of
congregating is quite at an end from the conclusion of wheat sowing to
the season of barley and oats, it is not the case with us; for larks and
chaffinches, and particularly linnets, flock and congregate as much in
the very dead of winter as when the husbandman is busy with his ploughs
and harrows.
Sure there can be no doubt but that woodcocks and fieldfares leave us in
the spring, in order to cross the seas, and to retire to some districts
more suitable to the purpose of breeding. That the former pair before
they retire, and that the hens are forward with egg, I myself, when I was
a sportsman, have often experienced. It cannot indeed be denied but that
now and then we hear of a woodcock's nest, or young birds, discovered in
some part or other of this island; but then they are all always mentioned
as rarities, and somewhat out of the common course of things: but as to
redwings and fieldfares, no sportsman or naturalist has ever yet, that I
could hear, pretended to have found the nest or young of those species in
any part of these kingdoms. And I the more admire at this instance as
extraordinary, since, to all appearance, the same food in summer as well
as in winter might support them here which maintains their congeners, the
black-birds and thrushes, did they choose to stay the summer through.
From hence it appears that it is not food alone which determines some
species of birds with regard to their stay or departure. Fieldfares or
redwings disappear sooner or later according as the warm weather comes on
earlier or later. For I well remember, after that dreadful winter
1739-40, that cold north-east winds continued to blow on through April
and May, and that these kind of birds (what few remained of them) did not
depart as usual, but were seen lingering about till the beginning of
June.
The best authority that we can have for the nidification of the birds
above-mentioned in any district, is the testimony of faunists that have
written professedly the natural history of particular countries. Now as
to the fieldfare, Linnaeus, in his "Fauna Suecica," says of it, that
"_maximis in arboribus nidificat_;" and of the redwing he says, in the
same place, that "_nidificat in mediis arbusculis_, _sive sepibus_; _ova
sex coeruleo-viridia maculis nigris variis_." Hence we may be assured
that fieldfares and redwings build in Sweden. Scopoli says, in his
"Annus Primus," of the woodcock, that "_nupta ad nos venit circa
oequinoctium vernale_;" meaning in Tyrol, of which he is a native. And
afterwards he adds "_nidificat in paludibus alpinis: ova ponit_ 3-5." It
does not appear from Kramer that woodcocks breed at all in Austria; but
he says, "_Avis hoec septentrionalium provinciarum oestivo tempore incola
est_; _ubi plerumque nidificat_. _Appropinquante hyeme australiores
provincias petit_; _hinc circa plenilunium mensis Octobris plerumque
Austriam transmigrat_. _Tunc rursus circa plenilunium potissimum mensis
Martii per Austriam matrimonio juncta ad septentrionales provincias
redit_." For the whole passage (which I have abridged) see "Elenchus,"
etc., p. 351. This seems to be a full proof of the migration of
woodcocks; though little is proved concerning the place of breeding.
P.S.--There fell in the county of Rutland, in three weeks of this present
very wet weather, seven inches and a half of rain, which is more than has
fallen in any three weeks for these thirty years past in that part of the
world. A mean quantity in that county for one year is twenty inches and
a half.