NOTES AND QUERIES. 



BIRDS. 



Can Woodpeckers see in the dark ? — My reason for asking this 

 question is as follows: — Some time ago I found a nest of the Green 

 Woodpecker, Picus viridis, the hole being bored in the trunk of a large ash 

 tree, about 15 ft. from the ground. After tapping the tree with a hammer 

 to ascertain the situation of the nest, I decided to cut a circular hole with a 

 chisel about 1 ft. below the entrance, and a very tedious operation I found 

 it, as I had to cut through nearly seven inches of very hard dry wood before 

 I reached the nest, which, to my great disappointment, contained only one 

 solitary fresh egg. Deeming it advisable to take it, as in all probability the 

 bird would forsake the nest, I removed it very carefully, and substituted a 

 newly-laid Thrush's egg, on the chance of the bird returning and laying to 

 it, closing up the hole I had made with a 3^-inch bung, filling up the 

 crevices with stiff clay, and rubbing some brown wood-dust over the outside 

 to make it look as natural as possible. On returning a few days later, 

 I tapped the tree with my stick, and was much pleased to see the Wood- 

 pecker's head appear cautiously at the mouth of the hole, when on seeing 

 me she flew away ; upon which I reascended the tree, removed the bung, 

 and to my surprise found four more fresh eggs. Now comes the point of 

 my question, for, instead of laying to the Thrush's egg, I found that the 

 bird had cast it out of the nest and deposited it at the far end of the 

 passage I had cut, close to the bung ; in fact, so close that had I not 

 removed the bung very carefully it would have fallen to the ground. Now 

 what I do not understand is, how the bird knew that it was not its own 

 egg. The hole was only just large enough, as usual, for the bird to squeeze 

 in, and therefore, when once it had entered and filled up the passage, the 

 nest must have been in total darkness ; and, unless it could see in the 

 dark, it is difficult to imagine how it detected the fraud, for the two eggs 

 being about the same size and shape would, I should have thought, have 

 been quite indistinguishable to a bird of that family in the dark. Of course 

 the texture of the shells is slightly different, but surely a bird would not 

 be able to detect that either in the dark. I have found the plan of boring 

 a hole opposite the nest and closing it with a bung to answer admirably in 

 the case of most birds that nest in the holes of trees, and adopted it often 

 when I was in India with great success, especially with Barbets, Parroquets, 

 Tits, &c. (vide Oates' edition of ' Nests and Eggs of Indian Birds,' vol. ii. 

 p. 326, under the head of Cyanops viridis, the Lesser Green Barbet). — 

 E. A. Butler (Brettenham Park, Ipswich). 



Early Nesting of Herons. — Owing to the unusual mildness of the 

 present winter, Herons commenced breeding very early, indeed earlier this 

 season than I can ever remember. By Jan. 15th I observed them haunting 

 their old nesting-places, and the unearthly sounds proceeding from them 



12 



