52 THE SCOTTISH NATURALIST 
succession which alters both specifically and quantitatively 
with the growth of the trees. The fauna is thus of an 
unstable or migratory type, and such is characteristic of 
woodlands planted by man, while our natural forests, which 
maintain themselves by self-sowing, have a relatively stable 
fauna. 
It is possible to trace with some approach to accuracy 
the faunai succession of a plantation. We may take as an 
example a coniferous plantation, situated in the glacial drift 
of the Lothians. A common type of sucha planting consists 
of mixed Scots pine and larch, with a smaller proportion 
of spruce. Its colonisation by birds takes a course some- 
what as follows: The first settler in all probability would 
be the Whinchat. I can recollect the colonisation of one 
such young plantation by the Whinchat within three months 
after planting. Nearly coincident with the Whinchat, but as 
a rule a year or so later, would appear the Tree-pipit and 
Yellow Bunting. All three species depend chiefly for the 
concealment of their nests upon the rough clumpy grasses, 
such as Deschampsia flexuosa, which at first springs up 
between the young trees. After the elapse of a year or two, 
particularly where spruce is present, we should find new- 
comers in the Whitethroat and the Hedge-sparrow. By 
about the sixth year the trees have reached sufficient size 
for Song-thrush, Blackbird and Willow-wren, three species 
which speedily assume a dominant position in the association. 
The numbers of the two Thrushes are directly affected by 
the proportion of spruce, which is preferred for nesting-sites 
over the other conifers present. Next in order come 
Greenfinch and Chaffinch, the latter soon greatly out- 
numbering its relative. Following these, in approximate 
order of arrival, would be Cole-tit, Goldcrest, Ring-dove ; 
and with an approach to full tree-growth, the succession 
is completed by such birds as Missel-thrush, Magpie, Carrion- 
crow, Sparrowhawk, and lastly the Owls, Long-eared and 
Tawny. 
It is to be noted that towards the period of full tree- 
growth, which accompanies the arrival of the later colonists, 
a corresponding falling off and gradual disappearance of the 
