ON THE INSTINCTS OF BIRDS. 129 
Bishop’s Waltham, in Hampshire ; and some birds, as 
already represented, frequently spare their own labour 
by taking possession of the nests of others. 
In these instances there certainly appears to be a 
great display of sagacity; yet there are facts which 
seem to render it doubtful whether the feathered 
tribes are capable of deriving much benefit from 
experience, or of exercising any remarkable degree of 
intelligence. Thus birds when engaged in the per- 
formance of their parental duties expose themselves, 
without hesitation, to dangers which at another period 
they would carefully avoid. Many species also, while 
under the incitement of appetite, are readily snared 
by the most simple contrivances, directly after wit- 
nessing the capture of their companions ; and Rooks 
continue to breed in those rookeries where the greater 
part of their young are destroyed every spring*. For 
three successive seasons a pair of Redstarts persisted 
in making their nest in the upper part of our pump, 
on that end of the lever which is connected with 
the rod of the piston, and, of course, always had it 
disturbed when that engine was used. Mr. White 
observest, too, that in the neighbourhood of Sel- 
borne House-Martins build, year by year, in the 
corners of the windows of a house without eaves, 
* JT was assured by the late T. Legh, Esq., that many thousands 
of young Rooks were shot every breeding-season in his extensive 
rookery at Lime Park, in Cheshire. 
+ ‘Natural History of Selborne,’ p. 160. 
