446 BIRDS OF DUMFRIESSHIRE 
and Mr. J. Reid tells me he has seen this species many years 
ago near Kelton, and once on the Nith within a hundred yards 
of Castledykes Cottage, which was at one time the residence 
of Sir John Richardson, the eminent Arctic explorer and 
naturahst, from whom this bird derives its trivial name.* 
The method used by Richardson's Skua of gaining a 
livelihood, consists in chasing the terns and smaller gulls 
and forcing them to relinquish any fish they may have 
taken ; it also preys upon disabled birds. 
There exist light and dark forms of this species, which, 
however, mate indiscriminately where they meet. The 
light-breasted form in its breeding-grounds may be said to 
predominate in the far north, the dark form being in the 
ascendancy in the south. As a breeding-species this Skua 
may be described as circumpolar, but it nests on the north 
of the Scottish mainland, locally in the Hebrides, and more 
plentifully in the Orkneys and Shetlands. In the autumn it 
migrates south ; and in winter it frequents the coasts of 
Europe down to the Mediterranean, West Africa as far as the 
Cape, the Persian Gulf, and the American coast as far south as 
California and Barbados ; while it has occurred in Tasmania 
and New Zealand. Along the Scottish seaboard and the 
eastern coasts of England this species is the commonest of 
the Skuas, and is a regular migrant in autumn. 
THE LONG-TAILED or BUFFON'S SKUA. 
Stercorarius parasiticus (Linnaeus). 
A scarce and irregular visitor. 
BufEon's Skua is, perhaps, the most irregular of the genus 
Stercorarius in its visits to this county ; but when these birds 
do come there is usually a party of them, or, when single 
birds have been observed, more usually follow. Richard Bell 
* Sir John Richardson was the son of Gabriel Richardson, a Provost 
of Dumfries, and was born in that town on November 5th, 1787. 
