WILSON'S PETREL 



211 



A single example of the Madeira petrel iOccanodroina cryptoleucura), 

 which is a darker bird than the last, with broader black tips to the 

 upper tail-coverts and the outer tail-feathers white at the bases, was 

 picked up dead in Kent in 1895. 



Wilson's Petrel 

 (Oeeanites 

 oeeanieus). 



All the casual visitors to the British Islands hitherto 

 noticed breed in the northern hemisphere, and reach 

 our islands from east, north, or west. Wilson's 

 petrel, on the other hand, nests in the Antarctic and 

 the Australasian islands, whence it wanders to the Indian Ocean and 

 the Atlantic, occasionally reaching the British Islands by the latter 

 route in autumn. This petrel, together with an allied species from 

 the American side of the South Pacific, represents a genus distinguished 

 from the two last by the claws 

 being somewhat depressed in- 

 stead of distinctly compressed, 

 by the relatively greater length 

 of the shank or lower segment 

 of the leg, which is covered in 

 front with a single greave-like 

 shield in place of a number 

 of small hexagonal shields, the 

 absence of the hind-toe, which 

 is represented only by a vestige 

 of the claw, the presence of 

 only ten secondary quills, and 

 the approximate equality in the 



length of the outer and middle toes. In addition to these features, 

 Wilson's petrel, which measures 7 inches in length, is easily recog- 

 nised by the }-ellow patch at the base of the webs of the toes, and 

 the squared tail. The plumage is for the most part of the usual 

 sooty black, but the upper tail-coverts and a patch beneath each 

 side of the tail are white, as in Leach's and the storm petrel, and 

 the bases of the tail-feathers, more especially the outer ones, are 

 also white. 



Apart from a number seen off the Land's End in 1839, Wilson's 

 petrel seems to have occurred about fifteen times in the British Isles 

 up to the end of 1900, so far as our records extend back. Most of 

 these occurrences have taken place in England, there being only one 

 instance of the species having been taken in Scotland, and that in Jura 

 in 1 89 1. One example is said to have been killed on the Irish coast 



WILSON S I'ETKEL. 



