Among the Water-Fowl 



presently arose to a crouching attitude, and ran back 

 into what was left ot the hole. Then I gave it a 

 toss into the air, and, after a little zigzag meander- 

 ing over the grass and rocks, it seemed to get its 

 bearings, flew down in its usual irregular manner to 

 the water, and disappeared off^ to sea, without show- 

 ing any inclination to return to the nest, nor did it, 

 that we could see, during the day. 



We dug out a number of other burrows till we 

 had seen enough to generalize the observations a 

 little. We did not And more than one egg in any 

 nest, and I do not know that any such instance has 

 ever been recorded. Sometimes there were two 

 birds in a burrow, but in these cases the ess had 

 not been laid. Two birds that I took in the act of 

 incubation from difl^erent nests and kept as speci- 

 mens proved to be males. Some observers have 

 thought that the male usually incubates, but others 

 are said to have found birds of either sex indiffer- 

 ently thus engaged. 



The puzzle is what becomes of the other 

 partner. Practically never is a Petrel to be seen by 

 day about the breeding-grounds. At night, how- 

 ever, the Petrels become active and noisv, twittering 

 constantly, and flying to and fro from the sea. We 

 cannot assume that the other is in some hole 

 near by, for all the birds found are incubating. 

 The fact also that the males incubate precludes the 

 possibility of their deserting their mates, as is the 

 case with the Ducks. Until something to the 

 contrary is shown, we evidently must be content 

 with the old theory that one bird of each pair flies 

 out to sea during the night, leaving the other on 



126 



