6 ANNALS OF SCOTTISH NATURAL HISTORY 



Mr. J. Paterson who is giving his attention to the fauna of 

 the " Clyde " area also records that in Wigtownshire, in the first 

 week of June 1894, a friend and himself found a nest, putting the 

 duck off. Up to this date he assures us Mr. R. Service had no 

 record of their nesting in Wigtownshire. Later again, referring to 

 Mr. Read's notes, Mr. Paterson, in the same journal (1895, P- I2 3)> 

 tells us that he has visited many localities in the S.W. which are not 

 yet colonised by the species, and illustrates the negative fact thus : 

 "I visited, in June 1893, Loch Moan in Ayrshire, Loch Trool in 

 Kirkcudbrightshire, without seeing it; while in June 1894 I was at 

 Lochs Ken, Harrow, Dungeon, and Munnoch in Kirkcudbrightshire, 

 and Mochdrum and Castle Lochs in Wigtownshire, and in only 

 one instance did I find any evidence of its presence" (see antea). 

 And he adds, "This is a great contrast to what obtains in East 

 Renfrewshire." 



Mr. Robert Service now takes up the tale, and in a letter to us 

 dated 2yth August 1895 m akes the following remarks: "The in- 

 crease seems to have reached here from a directly north-easterly 

 point. Since I first announced ("Zoologist," 1886, p. 342) its 

 breeding here, a few years ago, it has increased steadily, if slowly. 

 It is now breeding in something like half a dozen localities that 

 I might name in the Stewartry of Wigtownshire. I cannot say 

 that it has actually bred yet in Dumfriesshire, but there can be little 

 doubt that it has done so. The species is one of those that arrive and 

 depart from here in a N.N.E. or E. direction, and I never noticed it 

 going or coming with the great majority of our birds from the direction 

 of the Hebrides." [W T e have here placed Mr. Service's notes in italics.] 

 It is significant to find that the lochs of Wigtownshire, or those 

 nearer to the coast line, are not the first to have become populated 

 by breeding birds. Are the individuals arrested by the more favour- 

 able localities visible to them, first on their autumn N.E. to S.W. 

 migration, or does the occupation follow only upon their second or 

 spring observations ? i.e. are they arrested and induced to breed 

 more by the amenities of the place in spring than autumn 1 We 

 incline to the former belief, and that they are "brought up" or 

 arrested in spring by the unsuitability of the areas beyond. Once 

 acclimatised, or once they have reared young, the wave of dispersal, 

 as it were, rolls back upon itself over the "lines of least resistance," 

 and localities formerly passed over become occupied. This we 

 consider is a well-founded belief built upon the facts we are 

 able to bring forward not only here but in other areas we shall 

 treat of. 



Finally, and to date, we are indebted to Mr. J. Paterson, who has 

 sent us the most careful particulars of their movements and present 

 winter and summer distribution, which we consider to be well worthy 

 of reproduction in the form offered in the following table : 



