224 THE BIRDS OF THE BRITISH ISLES. 



turning and twisting as it descends. The quickest flight is 

 when in pursuit of some favourite food ; a big rise of May-fly, the 

 emergence and nuptial flight of crane-flies, "coch-a-bonddu," or 

 winged ants, excites the greedy birds. I have seen the air a 

 maze of dodging, screaming gulls, their white wings fluttering 

 as they checked their hurried rushes and swoops after the erratic 

 insects. Although omnivorous like other gulls, the Black-head 

 is undoubtedly a useful bird, especially inland ; it follows the 

 plough, wrangling with the Rooks and Starlings, or with its 

 companions, as it hastens almost to the ploughman's heels. 

 Stomach examination proves that though many worms and 

 some harmless insects are eaten, great numbers of "leather- 

 jackets " and wireworms are taken from the newly turned 

 ground, and Prof. Newstead's examination of a number of 

 pellets, picked up after a plague of crane-flies, was convincing 

 evidence of its value. In rivers and on the shore it devours 

 insanitary garbage, and is a faithful attendant on the fishing 

 fleet when the catch is sorted. It is true that a little grain is 

 picked up, and that a small percentage of fishy matter has 

 been found in the stomach, but the good it does far outweighs 

 the harm ; indeed, it is a poor fisherman, lacking speed and 

 diving skill, though I have seen it clumsily submerge when 

 attempting to capture fish. At dusk on the Welsh uplands, 

 far from the sea, I have watched it sweeping to and fro with 

 undulating swoops, picking ofl" the male ghost moths as they 

 hovered with their strange pendulum-flight above the long grass 

 —both birds and moths ghostly in the gloom. It will paddle 

 to bring food to the surface like other gulls, either in the 

 shallow tide-pool or the mud of a harbour. 



Inland, after feeding all day, it retires to some lake to roost, 

 bathing and preening before settling down ; on one Cheshire 

 mere considerably over a thousand collect nightly in winter ; 

 it will wash in the sprinkler tank on the roof of a cotton mill in 

 a busy Lancashire town. The corvine call note is harsh and 



