88 Cruise of the ''Alerts 



leg that is used. The object of this manoeuvre seems to be to give 

 the body sufficient upward impulse to prevent the wings from 

 becoming wetted in rising from near the surface. I have often 

 observed the Atlantic storm petrels steady themselves on the 

 water with both legs together, but have never seen them perform 

 this one-legged "kick," like their congeners of the Pacific. There 

 are contradictory statements in natural history works as to whether 

 petrels do or do not follow ships during the night time. Those 

 who adopt the negative view of the question maintain that the 

 birds rest on the waves during the night and pick up the ship 

 next morning by following her wake. For a long time I was in 

 doubt as to which was the correct view to take, although I had 

 often on dark nights, when sitting on the taffrail of the ship, fancied 

 I had heard the chirp of the small petrels. At length I became 

 provoked that after having spent so many years at sea I should 

 still be in doubt about such a matter as this, so I began to make 

 systematic observations, in which I was assisted by the officers of 

 watches and quartermasters, who were also interested in the matter. 

 The result is that I am now quite certain that the storm petrel 

 and Cape pigeon do follow the ship by night as well as by day, 

 and that, moreover, the night is the best time for catching them. 

 Every night, for a time, I used to tow a long light thread from 

 the stern of the ship; it was about sixty yards long, and fitted at 

 the end with an anchor-shaped piece of bottle wire, which just 

 skimmed along the surface of the water and yet allowed the thread 

 to float freely in the air. I found this device a great improve- 

 ment on the old-fashioned method of using several unarmed threads, 

 and in this way I caught at night-time, and even on the darkest 

 nights, both storm petrels and Cape pigeons; the latter, however, 

 usually breaking my thread and escaping. If I sat down quietly 

 and held the line lightly between my finger and thumb, I would feel 

 every now and then a vibration as a bird collided with it. On 

 moonlight nights, moreover, one could always, by watching care- 

 fully, see the big Cape pigeons flitting about the stern of the ship. 



