vol,, x.j POLYGAMY AMONG KOOKS. 279 



When the cock returned both birds ahnost mobbed him, 

 ISO eager were they for food. 



The following day, at another Rookery, a Rook was seen 

 to feed a hen on a nest and then go to a nest near, by and feed 

 another incubating bird. Here, in more than one case, 

 Rooks were seen feeding young which had reached a fair size ; 

 in these instances the hen Rooks sat by, not receiving any 

 food ; no doubt when the young grow larger, the hens leave 

 them at times, in order to forage for themselves. Later both 

 parents feed the young. 



At this Rookery, two days later, two nests, built side by 

 side, which I had previously noticed Avere apparently cared 

 for by one cock, were kept under observation. One of them 

 evidently contained small young. The cock came and fed 

 the hen and the young in this nest and then departed. Re- 

 turning after an absence of forty minutes he fed both hens 

 but not the young. 



On each occasion both hens quivered their wings at his 

 approach. 



The following year I watched closely at both Rookeries, 

 but could detect no case of a cock having more than one hen. 



The first of the foregoing instances is somewhat remarkable, 

 for in that case two hens shared the same nest, sat side by 

 side in the same nest hollow, and were obviously on the best 

 of terms with each other. 



