BIEDS. 105 



skylark ; and gunners recognise the curved neck of the 

 flying heron, and the drooping head of the woodcock. 



One episode in bird-life has, their breeding excepted, 

 attracted more attention than any other, and has formed 

 the subject of voluminous works by Gaetke, 

 ■ Dixon, and other writers. Much has yet to 

 be learnt with reference to their wondrous organised move- 

 ments, and the obstacles that lie in the way of systematic 

 observation are scarcely less formidable than those which 

 beset the investigator of marine life. So much is hidden, 

 for the wandering birds move often at great altitudes, 

 mostly at night. This preference for travelling at a 

 great height means, in all probability, that the birds find 

 the higher atmosphere clearer and less disturbed by cur- 

 rents. Their movements by night are, as may be imagined, 

 much influenced by lighthouses, and, to a lesser extent, by 

 the bright lights, mostly electric nowadays, of our harbour 

 and other seaside towns. The lighthouses cause the de- 

 struction of thousands that dash themselves against the 

 glass, sometimes right through it. 



Regular migrants, as the swallow, must be guided to 

 a great extent by transmitted instinct, for they "\^dll fly 

 straight north and south, and are known to follow the 

 shortest route over the sea, the track maybe of a former 

 isthmus. The swallows, type of birds of passage, will 

 cover over one hundred miles in the hour, will return 

 year after year to the same eaves, and, strangest of all, 

 will, on the wane of summer, and when the insect food 

 is giving out, feel the returning instinct so strong within 

 them as to leave a third brood to perish of starvation. 

 Of these summer visitors these islands are the native 

 land ; many of them remain for more than half the year. 

 Of the waterfowl, however, those wondrous hordes that 

 rear their young in the glow of the midnight sun, far 

 from the disturbing i^resence of man, they are but a 

 winter feeding-ground. 



With the casual migrants and stragglers, again, the case 



