The Bird Department 



By A. A. Allen, Ph.D. 

 Assistant Professor of Ornithology, t 'ornell University, Itfiaca, N. Y. 



THE NESTING OF THE BIRDS 



ANYONE who examines the beautifully woven nest 

 /-\ of the oriole, or inspects the tiny lichen-covered 

 home of the humming-bird, or even watches the 

 robin plastering his rough abode, must wonder at the skill 

 with which the coarse material is so neatly arranged. No 

 shuttle is necessary to tie the knots that fasten the oriole's 

 nest to the branch, ho loom to weave the bag that must 



NEST AND EGOS OF THE KILDEER 



Showing what is perhaps the first stage in the evolution of a nest, a 

 simple depression in the gravel, with no lining. 



hold the growing family. Very deftly the bird's bill 

 plys in and out and fashions a nest that might well defy 

 the skill of man to imitate. Why do birds build such 

 elaborate structures? How do they come by such 

 ingenuity? What is the meaning of the many kinds of 

 nests built by different birds and how has it all come 

 about? 



Xest building is not restricted to birds, not even to the 

 higher animals, for many insects make quite elaborate 

 structures for protecting their eggs. The strange nests 

 of many ants and bees and the care that is bestowed 

 upon the eggs and young are in many respects much 

 more wonderful than the structures built by birds and 

 the attention given to their offspring. 



With the vertebrate animals, we find true nest-builders 



among the fishes. There are many species of bass and 



catfish which deposit their eggs in shallow depressions 



in the lake bottom and remain to guard them and protect 



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the young. The little sticklebacks of our ponds and 

 streams build real nests of leaves and stems of water 

 plants and fasten them into the aquatic vegetation like 

 the nests of birds. But it is from none of these that the 

 birds have developed or acquired the nesting habit. We 

 must look to the reptiles for its origin because it is from 

 lizard-like creatures that the birds have sprung. 



The earliest known creature which we can recognize 

 as a bird was found in the lithographic stone of Bavaria 

 in 1861 and is called the archaeopteryx or ancient bird. 

 The chief differences between it and the bird as we know 

 it today is the presence of teeth upon its jaws, a long 

 lizard-like tail bearing feathers upon each side, and three 

 free fingers upon each wing, showing that it climbed 

 about the trees in addition to sailing from one to another. 

 Whether it was a cold-blooded or a warm-blooded animal, 

 we are unable, of course, to determine, but it was prob- 





AS IN THE EARLY BIRD DAYS 



The nest and eggs of the green heron, a crude platform of sticks repre- 

 sentative of the earliest tree nesters. 



ably intermediate, having a body temperature above that 

 of its environment but subject to variation. Its nesting 

 habits were probably but little more advanced than those 

 of reptiles today which deposit their eggs in the sand, 

 in decaying vegetation or in holes of trees and leave them 

 for the heat of the sun to hatch. In fact it was not until 

 birds became truly warm-blooded creatures, with the 



