148 A VERTEBRATE FAUNA OF THE MORAY BASIN. 



west coasts, and turn up in what, at one time, appeared a most 

 unexpected way, as we have instanced under our remarks on the 

 island of Tiree in a previous volume.^ 



Thus the ' slinks and wide estuaries of the Cromarty and Beauly 

 Firths, and the Bay of Findhorn, the sweeps of sandy shore between 

 Nairn and Burghead, and the still famous loch of Spynie, all afford 

 suitable resting- and feeding-grounds for many species in autumn. 

 So do the bosky dells and warm sun-lit valleys of the tributaries of 

 the Spey, where, whilst ' pursuing the angle ' for the spotted trout, 

 we find the whole glens seemingly alive with twittering myriads of 

 woodland species. So also do the great old pine woods of Strath- 

 spey and Tarnaway and Inverness-shire still continue to hold a 

 comparatively rich variety of our rarer raptorial birds and pine- 

 loving woodland species. So, likewise, when the water-fowl which 

 haunt our estuaries, and are the delight of our wild- fowlers, arrive 

 after an ocean journey, they find creeks, and lakes, and rivers, and 

 ponds, right and left of their lines of flight, admirably suited to 

 their requirements. It is, perhaps, only when they are extending 

 their breeding haunts and area, owing to quiet and preservation 

 and encouragement, that evidence occurs of their being influenced 

 by land-contours. Their progression as a race is at that time 

 usually from south to north. Thus we find the increase and spread 

 of the colonisation of many species tending to occupy the great 

 eastern drainage areas of our country — amongst which we may 

 instance the Tufted Duck, Shoveller, and Pochard. It is only after 

 congestion at the centres that they seek to diverge to the westward 

 of their old lines of autumn and spring migration, and ' overflow,' 

 as it were, through the passes which occur through the backbone 

 of Scotland.^ 



In conclusion, it appears evident that intimate connection 

 occurs between certain areas of occupation upon the shores of our 



1 Fauna of Argyll, etc., 1892. 



^ Local name in parts of Scotland for mud-flats or muddy foreshore. 



^ The outline of the Ross-shire mountains by Colin Phillip, illustrating his article 

 upon the sky-line of our western boundary, taken from a point commanding a view 

 of the whole Great Glen, will admirably illustrate our meaning of the ' overflow ' 

 towards the west, ' through the passes of the backbone of Scotland, ' or, in other 

 words, the ' lines of least and greatest resistance.' 



