CONCEALED OR COVERED NESTS 117 



where branches have been broken off. The Wrynecks 

 (lyngin^) form a small group associated with the 

 Woodpeckers in the family Picidas, nest in a very 

 similar manner, but are not known to excavate their 

 own holes, selecting these ready made, or at most 

 altering them slightly to suit their requirements. 

 Their eggs are laid upon the powdered wood at the 

 bottom of the hole. As an instance of perverted 

 habit, I may mention that the Green Woodpecker has 

 been known to bore its hole into the wooden spire of 

 a church in Norway. 



One of the difficulties with which we are confronted 

 in a work of the present character is that of classifica- 

 tion, a good deal depending upon the point of view 

 from which we deal with many types of nest. This is 

 especially the case with many hole breeding species in 

 the present class, not a few of which might with 

 almost equal propriety have been included with the 

 crudest nest-builders or even with nestless birds. I 

 have, however, decided to include them here although 

 alluding to some of them elsewhere, because they are 

 not only closely allied, but by seeking a ready made 

 hole they provide themselves with a cradle at least as 

 elaborate as other birds that excavate a similar hole 

 as in the case of the Woodpeckers. 



The first of these to be dealt with here is the family 

 of Hornbills (Bucerotid^e), numbering upwards of sixty 

 species, distributed over the Ethiopian and Oriental 

 regions and entering the Australian region as far as 



