THE SHELDRAKE 217 



In the North Frisian Islands, according to Yarrell, the natives 

 make artificial burrows and systematically rob the nests until the 

 middle of June, when they allow the birds to begin to sit. In this 

 way each burrow may yield as many as thirty eggs. In robbing the 

 nest care seems to be taken always to leave four or five eggs in 

 the nest, so that the suspicions of the bird are not aroused : for the 

 sheldrake appears to be of a wary disposition, often taking the pre- 

 caution to fly straight into the entrance of the burrow, so as to leave 

 no tell-tale traces of the whereabouts of its nursery. Generally, 

 however, more or fewer footprints at the entrance to the burrow will 

 be found, though none extend beyond it. Incubation extends over 

 a period of from 28 to 30 days, during which time the male watches 

 near at hand. Some valuable notes, generously placed at my disposal 

 by Mr. G. Cresswell, show that we stand much in need of careful 

 observation on the feeding-habits of the sheldrake during the incuba- 

 tion period, for he remarks of the numerous birds now breeding on 

 the warrens at Wolferton, Norfolk, that " so far as I can observe, the 

 diet of this bird must be entirely different in the nesting season to 

 what it is during the rest of the year. A few ... do visit the salts 

 and creeks occasionally, for a short time ; but only for what may be 

 called ' a wash and brush up,' and not for food. When the eggs are 

 set I do not think the birds move from the vicinity of the heath." It 

 may prove that they live on sand-lizards, beetles, and snails, varied 

 with a little grass. As soon as the young are hatched they are taken 

 down to the water by their parents, the male being as assiduous in 

 their care as his mate. According to Naumann, when the young are 

 hatched far from the water they are carried in the beak, but others 

 seem to incline to the view that the nestlings mount on to the back 

 of the parent and maintain their position by seizing hold of the 

 feathers of the back. Commonly, if not always, they go on their own 

 feet. Some interesting facts on this head are embodied in the 

 notes furnished me by Mr. Cresswell, who, writing of the birds breed- 

 ing on Wolferton heath, remarks that the old birds, in convoying 



