xxiv INTRODUCTORY. 



largely for this number to the various species of seals and whales : 

 possibly future investigation may add one or two more of these 

 animals to the list. 



Amongst the land mammals three are supposed to have formerly 

 inhabited Orkney, but were exterminated at a very early date 

 viz., the Keindeer, Eed Deer, and White Hare. Since the commence- 

 ment of this century all these, together with the Hedgehog and 

 Brown Hare (which latter animal we have no reason to suppose was 

 indigenous), were re-introduced directly by man. The Eeindeer died 

 out, the Eed Deer flourished, but had to be killed down for various 

 reasons, but the White Hare still exists in one island, and the Brown 

 Hare, where protected, is sufficiently numerous. The Brown Hare 

 had been previously introduced, but was said to have died out, and 

 again to have been tried with better results : we have no record 

 of when the Eabbit was imported, but it was abundant in 1693. 

 Of the whole number of species included in our list, seven are of 

 doubtful occurrence : two of these are bats, two are seals, one a 

 whale, and the other two are the Water Shrew and the Water Eat. 

 The omnipresent Brown Eat and House Mouse were, of course, 

 inadvertently introduced, but there is no date of when the occur- 

 rence took place. 



In our list of birds we have included no less than 223 species. Of 

 these the Great Auk is extinct everywhere. The Ptarmigan has been 

 exterminated entirely in the islands ; the Sea Eagle is only now 

 an occasional visitant there ; the Golden Eagle is still rarer. All 

 these were at one time residents, and seem to have been directly 

 extirpated by man. Indirectly i.e. by means of cultivation and 

 draining several species are getting rarer, but this is compensated 

 in some degree by the spread of others which are more dependent 

 on this cultivated area. Of those birds which man has tried to in- 

 troduce viz., the Pheasant, Partridge, Eed-legged Partridge, and 

 Black-game, none seem to have thriven, if indeed the most promis- 

 ing of all, the Partridge, has not now vanished like the other three. 



Of the whole number, 223, we may take twenty-three species 

 as of doubtful occurrence. Most of these doubtful ones are in- 

 eluded in brackets ; the notes to the others will indicate sufficiently 

 those that are meant. 



