B I R 
B I R 
fcend from thefe regions at the approach of winter; 
numbers to which the army of Xerxes was but 
comparatively fmall 5 and which Linnsus has ob- 
ferved, for eight whole days and nights fucceflive- 
ly, to cover the furface of the River Calix, 
Thele fowls generally migrate from the north- 
ern countries in the month of September, and dif- 
perfe themfelves over all the fouthei n parts of Eu-' 
rope. To obferve the order of tlieir flight, is in- 
deed am.ufing : fometimes they range themfelves in 
a long line; and, at others, they march angularly, 
forming tv/o lines which unite in the centre. The 
leader at the point feems to cleave the air, as if to 
facilitate the paffage of thofe which are to follov/; 
and, when weary of this laborious ftation, retreats 
into one of the wings of the file, and is fucceeded by 
another pilot. About the beginning of Oilober 
they make their firft appearance with us, circulat- 
ing round our fliores; and, when compelled by 
fevere froft, repairing to our lakes and rivers. 
Some, indeed, of the web-footed fov/ls, of hardier 
conftitutions than others, endure the rigours of 
the northern climates during- the whole winter: 
but, when this feafon is uncommonly fevere, they 
are obliged to betake themfelves to more fouthern 
fkies ; and at fuch periods only we are vifited by 
the diver, the wild fwan, and the fwallow-tailed 
fheldrake. 
That irrational animals fliould be able to perform 
fuchlong journics, and hov/ they flwuld know when 
and whither to direft their courfes, has often afford- 
ed matter of contemplation to the curious : but tlie 
fame inftinfl which governs all their other aftions, 
certainly operates here alfo. Indeed, they radicr 
follow the weather than the country; and, when 
they perceive the variations of the air in their fa- 
v^our, they proceed in their journey till they difco- 
ver land to reft on. It can hardly be fuppofed that 
they retain any rem.embrance of that country in 
which they had fpent a former winter: nor is it 
probable that they can difcern,-from their height in 
the air, thofe regions to which they travel; fince, 
though they fhould afcenci even for miles, the con- 
vexity of die globe muft interrupt their view. 
There is, however, a circumilance attending 
the magration of fwallows, which envelopes this 
fubjedl in great obfcurity. At the approach of 
winter in Europe, it is univerfally allowed that 
they are feen in amazing numbers migrating into 
other climics ; and that their return into this country 
is about the beginning of fummer: but it is equally 
true, that many of them continue here during the 
winter in a ftate of torpitude, making old walls, 
or the hollows of trees, the places of their retreat ; 
and even finking in clufters to the bottoms of the 
deepeft lakes, where they repofe in perfe(5l fecu- 
fity. 
It feem.s difficult, however, to account for the 
various methods which thefe animals make ufe of 
for eluding the feverities of winter. It has been 
fuppofed by fome, that their blood lofes it's motion 
through the cold : but if Buffon, v/hois faid to have 
placed many of this tribe in an ice-houfe, found 
that the fame cold, by which their blood was con- 
gealed, v/as alfo fatal to their exiftence; it is doubt- 
ful whether there may not be a fpecies of them, 
though apparendy like the reft, formed internally 
fo as to be fitted for a ftate of infenfibility during 
the winter in this country. Some naturalifts, in- 
deed, have fuggefted, that the fwallows which re- 
main thus torpid may be only fuch as are either 
too weak, or were hatched too late, to join the ge- 
neral convoy: yet on thefe laft Buffon tried his 
experiment, and they all died under the operation. 
But though fome Birds, by emigrating, make 
their habitations in different parts of the earth, al- 
moft every climate has fowls peculiar to itfelf. 
Thofe of the temperate zone are not very remark- 
able for the beauty of their plumage; but the 
fmaller kinds fully com.penfate this defe6t by the 
melody of their voices. The Birds of the tor- 
rid zone are very bright and vivid in their colours, 
but they in general have either harfli and difagree- 
able voices, or are totally f lent : the frigid zone, on 
the contrary, where the adjacent feas abound with 
fifli, is ftocked vv'ith Birds of the aquatic kind, in 
much greater plenty than in Europe; and thefe are 
generally either cloathed with warm coats of fea- 
thers, or have large quantities of fat lying be- 
neath their fl<ins, which ferve to defend them from 
the rigours of the climate. In all countries, how- 
ever, Birds are longer lived than quadrupeds or 
infe6ts of the fame clim-atcs. Even "the life of 
man is fliort when comipared v/ith the lives of fome 
Birds : it is faid that fwans have fom-Ctimes lived 
three hundred years, and that geefe have been often 
knovv^n to exceed fourfcore ; wliile linnets, and other 
fmall Birds, feldom furvive fourteen or fifteen. 
Birds are in general lefs than quadrupeds; that 
is, the largeft of the one clafs is far fuperior in mag- 
nitude to the largeft of the other. The oftrlch, 
v/hich is the biggeft of the Bird tribe, bears no pro- 
portion to the elephant; and the fmalleft humniing- 
bird, the moft minute of the clafs, is confiderably 
lefs than the moufe. In thefe the extremities of 
nature are plainly difcernible : the oft'rich, feem- 
ingly covered with hair, and incapable of flight, 
approaches the quadruped clals ; while the hum- 
ming-bird, which hardly exceeds the humble-bee 
in magnitude, and has a fluttering motion, feems 
nearly allied to the infc6t race. But thefe extre- 
mities are rather objefts of human curiofity than 
utility : it is the middle order of Birds which man 
has taken under his protection, and which admini- 
fters to hisple:afures and his necefnties. ¥/ild Birds 
are, for the moft part, of the fame magnitudes and 
ftiapes; and ftill retain ftrong marks of their ori- 
ginal nature. But it is far otherwife with do- 
meftic fowls : thefe, changing at the will of man, 
and according to the variety of climates to which 
they are configned, the food with which they are 
fupplied, and the purpofes for which they are em- 
ployed, vary in their colours, fhape, and magni- 
tude, as well as in the nature and tafle of their flefli. 
That Birds are capable of receiving inftrudion, 
is abundantly manifeft-. h very furprizing inftance 
of this kind was feen a few years ago in London ; 
where a Canary Bird was taught to pick up the 
letters of the alphabet, and fo to arrange them at 
the word of command, as to fpell the name of any 
perfon in comipany; v/hile the motions which on 
this occafion were given by the mafter, and obeyed 
by the little animal, eluded the difcernment of every 
fpe6lator. 
The remarkable docility of the hawk, the par- 
rot, the magpye, the bullfinch, and a variety of 
other Birds, can hardly have cfcaped the notice of 
the moft fuperficial obfervers of nature. 
Birds are diftinguiflied either by their living on 
the land or in the water; and both clafTes are eafily 
known by their legs and toes. The toes of ail 
land Birds are divided, without any membranes 
or webs between them; and their legs and feet 
ferve for the purpofes of running, grafping, and 
1 B climbing. 
