466 



SLEEP OF BIRDS. 



penny sterling for every sixty larks. The quantity may seem pro- 

 digious, but the fields appear to be covered with them from Michael- 

 mas to Martinmas. 



These birds are seen in Egypt, about Cairo, in like number, the be- 

 ginning- of September, and continue for some days ; they are supposed 

 to come from Barbary, and are called in Egypt Asfour Dsjebali, or 

 Mountain Birds. 



Whether any portion of the northern breed of these birds visit us in 

 winter is not certain, but it is obvious that at particular times they are 

 infinitely more abundant in the southern provinces than at others ; 

 possibly they only quit one part of the kingdom, and assemble in 

 another, where the climate is more mild. In the winter of 1803, large 

 flocks of these birds were seen in every stubble-field in the south of 

 Devon, in number far beyond any thing that has since appeared.* 



SLEEP OF BIRDS. — Like horses and some other quadrupeds, a 

 great number of birds sleep standing; the perchers, (Insessoresy 

 Vigors,) for example, usually sleep standing on one leg upon some 

 tree, brush, or other elevation, with the head turned behind, and the 

 bill thrust under the feathers on the back, or under the wing. Indeed, 

 these appear to be the general habits of the whole race of birds, in 

 regard to their mode of resting and sleep ; for the duck and goose, 

 although they do not perch, will frequently sleep standing on one leg 

 upon the ground, with their heads turned round, and the bills under 

 the wing. Poultry, although they invariably perch, if a perch can 

 be obtained, do not, when sleeping, rest usually on one leg ; but they 

 sink down with their bodies upon the perch, having their legs com- 

 pressed under them. The sky lark sleeps upon the ground with his 

 legs also similarly compressed. It is probable also that all the tribes of 

 birds, even the perchers, occasionally sink down with their bodies rest- 

 ing on the perch during their soundest sleep. What is very remark- 

 able in the structure of their feet and legs is, that the greater the weight 

 upon the muscles, the more firmly the claws grasp whatever they lay 

 hold of ; hence the cause that birds do not fall down in sleep, although 

 most of their senses are dormant. 



The motion of the branches of trees produced by the wind increases, 

 doubtless, the disposition for sleep in many birds ; this may be exem- 

 plified in the common fowl ; for placing its bill under the wing, even 

 in broad day light, and swaying it to and fro in the hand for a very 

 short time, will produce sleep. Most of the tribe of birds sleep during 

 the night ; but there are many exceptions to this. Owls in particular 

 are, during the night, much more active than in the day ; their sight, 



