140 BIRDS OF THE COUNTRYSIDE 



migrate at the approach of rough weather in the autumn 

 independently of any fixed period of departure, or is 

 it scarcity of food that drives them, or do they select 

 a more or less calm day for crossing the Channel ? The 

 question has not been answered by observation, because 

 swallows (like other species) are notoriously irregular 

 in the choice of a time for leaving our shores. Certainly 

 they linger on almost into November in the south-west, 

 when the conditions are kind. But do they wait until 

 the weather becomes boisterous, until, that is to say, 

 their chances of destruction are at a premium ? Cold 

 should do them little harm, but storm would mow down 

 their ranks like a machine-gun. Very well, then, they 

 do not thus wait upon disaster, or they would not have 

 survived and flourished to their present prosperity. 

 The supplementary losses due to storm over and above 

 those that annually befall them in manifold forms 

 would have been too much for the continuity of the 

 race. Probably the swallows once did wait thus, but 

 by the experience of catastrophe they contrived to 

 learn a gradual good sense, calling, it would seem, 

 for a good deal of sagacity over and beyond instinct, 

 and fused, by continual practice, into habit. No 

 doubt the habit is still imperfect and the swallows have 

 some way to go before they can become as weather- 

 tight and weather-wise as avian prudence and fore- 

 sight can achieve. If they ever do so learn their job, 

 and (apart from the interference of man ^) still further 

 minimize their losses, it would naturally follow that 

 they would rear still fewer offspring in a season, it being 

 a truer economy to have fewer young that live than 



travel a thousand miles in a few hours ? how do birds avoid travel- 

 ing in circles at night ? how do they anticipate weather changes ? 

 how, at twenty thousand feet above the ground, can they tell the 

 end of the journey ? Compared with these miracles, the changing 

 of the water into wine reads like a conjuring trick. 



1 It is one of the saddest things among all those melancholy 

 reflections that haunt the modern naturaUst that the barbarians 

 of France, Spain and Italy are exterminating the swallow, out 

 swallow, loving and beloved of England. It is to these unciviUzed 

 races that we owe this robbery. Three milUon swallows were 

 killed in the South of France for millinery and food in one year. 



