270 Gyiigell : On the Nesting Habits of the Rook. 



never have I seen a bird pull a living- twig- from a tree, as is, 

 I think, their invariable custom when building- in spring. Of 

 course I am familiar with the pretty fancy that rooks repair 

 their nests in autumn in order that they may withstand the 

 winter g-ales, but although I have watched their autumn work on 

 many occasions I have never seen anything but a sort of toying 

 with the nest. 31st October and 17th November I may mention 

 as actual dates when the birds have been seen at nest-play. 

 Living trees are generally, but not invariably, selected to 

 support the nest. I have seen young reared in a nest built 

 in a perfectly dead poplar tree in a garden. I have counted 

 thirty nests in one tree. Want of sagacity seems very 

 apparent in the nest-building of some birds. On an estate 

 near Scarborough where there are high trees, both conifers 

 and deciduous, supporting other rookeries, a small colony 

 occupies a lot of hawthorn bushes, the nests being not more 

 than twelve feet high. One year a pair of birds built a nest in 

 a large tree in our Valley Park so close to the Valley Bridge 

 that errand boys constantly harassed the birds by tossing stones 

 into the nest and breaking the eggs. After repeated efforts the 

 nest owners reared an odd young one, but, failing to profit by 

 experience they re-occupied, but w^ithout repairing, the same 

 nest the following season and with no better results. 



The birds of each local rookery seem to have their own 

 regular time for nest-building, and what appears to be one 

 large rookery may really be several smaller rookeries in close 

 proximity. Thus, all the nests at one end of a plantation may 

 be finished before building has fairly commenced at the other 

 end. Strange to say, the earliest builders I know in this district 

 occupy a few isolated trees in an exposed position near the high 

 cliff top. 



During the whole time of nesting, from March till July, the 

 Rooks cast up pellets which may be found on the ground 

 below the trees. I have examined these pellets from different 

 rookeries and in different years and find them to be composed 

 almost entirely of corn-husks and coarse grit. Rooks have eggs 

 in the nest generally by the last week in March ; four or five are 

 usually laid, but nests often contain six eggs. Average weight 

 of an egg, -56 oz. 10 % of the eggs are marked chiefiy at the 

 smaller end. 



Although as noted above, I have never found a Rook's nest 

 containing wool, all the Carrion Crows' nests (about thirty) 

 examined have been well lined with wool. 



Naturalist, 



