7 
ax: 3 
THE NATURAL HISTORY OF SELBORNE. soe ot at 
regions, and especially birds of prey, whose blood being 
heated with hot animal food, are more impatient of a sultry 
climate; but then I cannot help wondering why kites and 
hawks, and such hardy birds as are known to defy all the 
severity of England, and even of Sweden and all north 
Europe, should want to migrate from the south of Europe, 
and be dissatisfied with the winters of Andalusia. 
It does not appear to me that much stress may be laid on 
the difficulty and hazard that birds must run in their migra- 
tions, by reason of vast oceans, cross winds, etc. ; because, if 
_we reflect, a bird may travel from England to the Equator 
without launching out and exposing itself to boundless seas, 
and that by crossing the water at Dover, and again at Gibral- 
tar. And I with the more confidence advance this obvious 
remark, because my brother has always found that some of his 
birds, and particularly the swallow kind, are very sparing of 
their pains in crossing the Mediterranean ; for when arrived 
at Gibraltar they do not 
* Rang’d in figure wedge their way, 
or and set forth 
Their airy caravan high over seas 
Flying, and over lands with mutual wing 
Easing their flight” : 
(MILTON) 
but scout and hurry along in little detached parties of six or 
seven in a company; and sweeping low, just over the surface 
of the land and water, direct their course to the opposite con- 
tinent at the narrowest passage they can find. They usually 
slope across the bay to the southwest, and so pass over opposite 
to Tangier, which, it seems, is the narrowest space. 
In former letters we have considered whether it was prob- 
able that woodcocks in moonshiny nights cross the German 
Ocean from Scandinavia. As a proof that birds of less speed 
may pass that sea, considerable as it is, I shall relate the fol- 
