BIRDS IN FLOCKS 71 



existence seems to spread among them as the vital sun 

 declines. 



Though this change becomes unmistakably conspicuous in 

 September, its beginnings are visible long before. Just as 

 the new song of the robin and the new thrusting of the leaves 

 and buds of the primrose seem to reach forward from autumn 

 to spring, so even in June or early July the first gathering of 

 small flocks and parties of birds gives a sign of coming 

 autumn to the watchful eye. The date of the change depends 

 a good deal on the weather. If there is a sudden spell of 

 wet and cold, even as early as the second or third week of 

 June we may see the first party of five or ten plovers, perhaps 

 attended by a few starlings, or fraternising tentatively with 

 half a dozen jackdaws. They appear in pastures where they 

 have not been seen during the breeding season ; and they 

 seem to regard the spell of wind and rain as a sign that 

 autumn is already coming, and that the time for the old kind 

 of life is past. Once they have begun to pack, they do not 

 break up into family parties, or attach themselves definitely 

 to a single spot, even though, as often happens, the weather 

 soon turns fair again, and the hottest part of the summer is 

 still to come. The casual association of a party of plovers 

 with one of jackdaws or starlings may be merely the acci- 

 dental consequence of meeting on one feeding-ground, and 

 species may part company from species at a slight alarm. 

 But once the instinct of flocking is reawakened, it does not 

 slumber ; and week by week the wandering parties of rooks, 

 jackdaws, starlings and plovers become more frequent in the 

 pastures, and on the shorn hayfields, and in the green salt 

 marshes by the sea and tidal rivers. Early in August wood- 

 pigeons begin to appear in these mixed flocks ; they are later 

 breeders than the other species, and are busy with eggs or 

 young until long after midsummer. Curlews which have 



