INTRODUCTIOiSr. 
xlix 
approaches, she increases her assiduity and care. The greater part of the 
business of incubation devolves on the hen.''^ If she observe that she is 
watched, she will cautiously avoid returning while the observer is near, 
and if she be driven from the nest she steals privily from it, and endeavours 
to escape without notice. She retires from the sight by a slow, silent 
movement, through the thickest part of the bushes that surround her. The 
males of most of the Sparrow kinds, during the period of ineubation, select 
some favorite branch contiguous to their nests, from which they serenade 
the female: but the males of the Hawk kinds keep in general at some 
distance. Toueh but the eggs of the Wood Pigeon, the Blackcap, the 
Yellow Bunting, the Whitethroat, and the Redstart, and they will in 
general forsake them : but the Robin, the Chaffinch, the Hedge Sparrow, 
the Blackbird, the Thrush, the Linnet, the Greenfinch, the Titmice, and 
the Red-backed Butcherbird, will often suffer a part to be taken away, and 
changed for others differently coloured, or of a different size ; follow their 
nest, though it be removed to some distance from the place in which they 
erected it, and hatch and foster the adventitious progeny."" But this 
peculiarity appears like caprice, since birds of the species just mentioned as 
less shy than their fellows, will often desert their nests if they be touched, 
and yet at other times they will sit on, and hatch the eggs of other birds, 
and even carefully attend the suppositious brood. The larger the bird, the 
longer time, in general, are the young in attaining maturity. The smaller 
species are commonly excluded in fourteen, or at most sixteen days, while 
others, such as the gallinaceous and Crow kinds, in about twenty-one ; many 
It is not a little remarkable, that the male Yellow Bunting attends more to the duty of 
incubation, in general, than the female. 
Birds commonly quit their eggs for a short time in dark cloudy weather, to feed, as if aware 
that the cloudiness of the atmosphere, presaged the coming of rain. 
I have often removed the nests of birds of the Sparrow kinds, and I have found many of 
them follow them even before they were finished, and at the time of incubation, and when they 
contained young. 
H 
