346 NATURAL HISTORY OF BIRDS. 



a nocturnal lifo, it of nccessitv liiinls by <l:iyliglit during tlic summer. But as it is 

 I'ssL'iitially a forest bird it keeps in the sliadow of the trees as much as possible, and 

 lias bi'en observed to be most :utive when the sun is at its lowest ]«jint. Its food is 

 stated to consist largely of hares and smaller mammals, but in Alaska Mr. Dall found 

 it feeding almost entirely on birds. 



The structure and afiinities of the singular East Indian J'/iofh'li(s (or J'/iolodilns) 

 have already been briefly alluded to, and, as we are unable to ja'esent any account of 

 its habits, we need only add here that the single species, P. l/adiits, is a native of the 

 eastern ]>arts of India, and lias l)een found in Ceylon, Java, and Borneo. 



Tlie l)arn-owls (suli-family Ahiconiiia-) form a small grou]), the membere of which 

 resemble each other very closely, while they differ strikingly from all other owls. We 

 liave already shown how different is their bony structure, and their sujierficial appear- 

 ance is e(iually remarkable. 'J'iie facial disk here reaches its highest develojiment, l>ut 

 instead of being more or less circular, as in all other owls whore it is well develo])ed, 

 it is elongated and almost triangular, giving the face a most remarkable expression, 

 not distantly resembling that of some monkeys. Moreover, the head is much j)r<> 

 duced in front, the bill being much longer ])ro])ortionally than in other owls, while the 

 legs are also long ;md scantily featliered, and the grotesque movements and strange 

 j>ostures which the bird assumes still furtiier increase its singularity of appearance. 

 Tlie ty]ie of the sub-family is the European barn- or screech-owl, Ahtco Jlanuueiis, 

 represented in Xortli America by a sligiitly different form, the r.ace or sub-species 

 pratiitcola of most authors. 



The barn-owl has a remarkably wide distribution, its range being greater than that 

 of any other owl. It is not found in New Zealan<l ; in America it does not ordinarily 

 pass north of latitude 45°, and is unknown in Scandinavia, but with these exceptions 

 it probably occurs all over the world. 



Correlated with this extensive range, we find great variability, and many of the 

 more or less jiermanent 'varieties' or races have long been considered true species. 

 Thus North American birds are almost invariably darker than average European ones ; 

 but a dark ](liase very like that of the American bird sometimes occurs in Germany 

 or Englanil, while specimens from the West Imlies are fully as light colored as the 

 lightest Euro]>ean ones, ami aljout equalled in this resj)ect by Australian birds. Not 

 only do the colors vary in kind and intensity, but the pattern of coloration is some- 

 what variable; some birds l)eing irregularly barred 1)elow, others s]H)tteil, and still 

 others immaculate white. In most of the races the tail has from four to six dark bars, 

 b\it .lamaican birds have the tail ]>ure white, and English ones almost so. There is, 

 furthermore, considerable difference in si/e, .and some slight difference in the ])ro]ior- 

 tions of ]iarts. Tlie smallest birds are jjrobably those of Euro]>e, scarcely exceeded, 

 however, by the South American form, while the North American birds are much larger 

 than the European, and these again are far excelled by those of Java and Australia. 



All these forms and many others were formerly ranked as so many separate s]>ecics, 

 but out of fifteen or twenty names in general use a score of ye.ars ago for forms then 

 considered 8i>ecitically distinct, all but four or five are now pretty generally admitted 

 to indicate only geogra])hical races, or light and dark j)hases of the single species, 

 Aliivo ^flamvicus. These four or five seem to differ more strongly from the common 

 tyjie than any of the others, but it is noticeable tliat even here the differences .arc 

 entirely of degree, and not of kind ; the principal points being depth of color, degree 

 of spotting, and size or shape of spots. 



