NESTS AND NEST-BUILDING IN BIRDS: Part III 



FRANCIS H. HERRICK 



Western Reserve Unii)ersity, Cleveland, Ohio 



Four figures 



CONTENTS 



6. Nidification: The Builders at Work. Nest-Building in the Robin. Choice of 



Nest-Site. Robin's Nest No. 1. Selection and Treatment of Materials. 

 Molding and Turning. Alternating in Turning. Nest No. 2. Lack of 

 Attunement in Instincts of the Male. Rehition of Nest-Building to Egg- 

 Laying and Incubation. Nest No. 3. Treatment of White and Colored 

 Materials. Nest-Building in the Red-eyed Vireo. Building of the Oriole's 

 Nest. Materials of the Oriole's Nest. Suspension of the Oriole's Nest. 

 Nest-Building in Other Species: Chebecs, Bluebirds, Chipping Sparrows, 

 Woodpeckers, Chicadees, Kingfishers, and Swallows. Cooperation in Nest- 

 Building. 



7. Intelligence in Nest-Building. 



8. Origin of the Instincts of Incubation and Nidification in Birds. 



In earlier sections of this paper we have tried to analyze the 

 structure of the nests of birds in the terms of behavior in order 

 to find a true basis for their classification, as well as to rightly 

 weigh the significance of the variations which they present. 

 We have seen that while protection is the prime function of the 

 nest, the structure of the latter is but one of many variable 

 elements through which the necessary protection of the Species 

 is secured. 



•It has been further shown that nest-building is one of a series 

 of complex and correlated instincts pertaining to the repro- 

 ductive cycle of birds, and that it is as truly ingrained as either 

 the form or color of the egg, but this is not all; these serial 

 instincts do not invariably proceed in due order and harmony. 

 The chain is liable to weaken or snap at more than one point. 

 The cycle may be normally repeated more than once in the 

 season, and when begun it may be brought to a sudden close 

 not alone through accident or fear, but by the rise of other in- 

 stincts or by any disturbance which affects the usual rhythms. 

 To such causes are due some of the most extraordinary phe- 

 nomena of nests and nest life, such as the " cuckoo instinct," 

 double, compound, or superimposed nests, the desertion of 

 the last young, the late building or " repairing " of nests which 

 come to naught, and to the " overlap " of instincts, which often 



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