COLUMBIFORMES. 381 



a cheesy substance excreted by the glands of the crop, then by 

 soft food from the crop itself. The nests are formed in trees 

 and on rocky places, sometimes in holes in decaying trunks : 

 they are flat structures composed of loosely united twigs upon 

 which the longish, shiny white eggs (two in number) are laid. 

 There are four species found in England — the Wood -pigeon 

 (Columba palumbus), the Stock-dove (C. cenas), the Eock-dove 

 (C. livia), and the Turtle-dove {Turtur communis). 



All pigeons have long and powerful wings, and can fly im- 

 mense distances. The sense of sight is extraordinarily keen. 

 Most species feed on the ground, but do not scratch about like 

 fowls {GallinoB), nor do they usually dust themselves in so-called 

 " dust-baths '' — they prefer water in which to clean themselves. 

 They differ again from fowls in drinking : the fowl takes short 

 draughts, holding up its head between each sip; the pigeon 

 takes one long bibition, its beak immersed in the water the whole 

 time. Pigeons feed exclusively on vegetable food. In the genus 

 Columba the base of the upper mandible is covered with a soft 

 skin in which the nostrils are pierced, and the twelve tail-feathers 

 are nearly even. In Turtur there are two tumid soft substances 

 at the base of the upper mandible covering the nostrils. 



The Wood-pigeon (O. palumbus) does much damage. It is 

 also known as the ring-dove and the queest. Its recent in- 

 crease is due partly to the killing off of all the large birds of 

 prey and to the increase of coverts. It is most abundant on 

 our eastern coasts, where large numbers arrive from the Contin- 

 ent. They commence to breed in April ; a second nest is 

 formed in June, and a third even in October. The nests are 

 placed in all manner of places — on high trees, in ivy, and on 

 low bushes. Incubation lasts eighteen days, and the young are 

 blind until the ninth day. The male sits aU day, the female of 

 a night. They unite in large flocks after the breeding season 

 is over. In spring and summer they are seen in pairs : at this 

 time they feed on the young leaves of peas, beans, and com ; 

 and turnips when young are also greedily devoured. Often whole 



