OSPREY 



397 



Osprey (Pandion 

 haliaetus). 



The last British representative of the diurnal birds- 

 of-prey is the osprey, now generally regarded as 

 representing a family (Pandionidai) by itself. From 

 all other members of the order this species differs in that the 

 outer toe can be turned backwards, so as to act in conjunction with 

 the hind one in owl-fashion ; and, in correlation with this peculiarity, 

 the bones of the leg likewise approximate to the corresponding 



portions of the skeleton of the owls. Another resemblance is shown 

 by the absence of an after-shaft to the feathers, which is present in 

 all other Old World Accipitres. These peculiarities in structure have 

 led to the opinion that the osprey forms a connecting link between the 

 falcon group and the owls ; but it seems possible that the first named, 

 at any rate, is merely an adaptive, although deep-seated, modification 

 for a particular mode of capturing prey. As the reversible outer 

 toe is amply sufficient to distinguish the osprey, it will be unnecessary 

 to allude to any of its other structural features except that the under 



