182 NATURAL HISTORY 
cious. All the hirundines of a village are up in arms 
at the sight of a hawk, whom they will persecute 
till he leaves that district. A very exact observer 
has often remarked that a pair of ravens, nesting 
in the Rock of Gibraltar, would suffer no vulture 
or eagle to rest near their station, but would drive 
them from the hill with an amazing fury: even the 
blue thrush, at the season of hatching, would dart 
out from the clefts of the rock to chase away the 
kestrel or the sparrow-hawk. If you stand near 
the nest of a bird that has young, she will not be 
induced to betray them by an inadvertent fondness, 
but will wait about at a distance, with meat in her 
mouth, for an hour together. 
Should I farther corroborate what I have ad- 
vanced above by some anecdotes which I probably 
_ may have mentioned before in conversation, yet 
you will, I trust, pardon the repetition for the sake 
of the illustration. 
The fly-catcher of the Zoology (the stoparola of 
Ray) builds every year in the vines that grow on 
the walls of my house. A pair of these little birds 
had one year inadvertently placed their nest on a 
naked bough, perhaps in a shady time, not being 
aware of the inconvenience that followed. But a 
hot sunny season coming on before the brood was 
half fledged, the reflection of the wall became in- 
supportable, and must inevitably have destroyed 
the tender young had not affection suggested an 
expedient, and prompted the parent birds to hover 
over the nest all the hotter hours, while, with wings 
expanded and mouths gaping for breath, they 
screened off the heat from their suffering offspring. 
A farther instance I once saw of notable saga- 
