164 Howe, Breedmg Habits of the Robin. [April 



fice it to say, I have found the nest from two to fifty feet eleva- 

 tion, and in ahnost every growth of tree common to this locality, 

 as well as on buildings, and others in such places as old carriages, 

 wood piles, etc. 



Construction of Nest. 



Having watched a number of nests during construction, I have 

 been able to determine a fair average of the time required, and 

 other interesting points. 



After the site has been chosen the building of a substantial 

 foundation of twigs, grasses, string, etc., is begun; this finished, 

 finer grasses are brought and the bird standing in the centre of 

 the foundation draws them round. After the sides of the nest 

 have been fairly well made the bird by turning around in the 

 nest shapes it to the exact contour of its body, and by pushing 

 its breast far down into the nest and raising the primaries, it 

 presses the nest with the wrist of the wing into a compact and 

 perfect mass. The next work is the plastering with mud ; a rainy 

 day is generally chosen for this work ; the bird brings the mud 

 in its bill and, placing it on the inside of the nest, flattens it into 

 shape by exactly the methods just described. All that remains 

 now is the lining, which is made of fine grasses and which 

 adheres to the mud, making a substantial though not a particu- 

 larly beautiful nest. 



The average measurements of nest are ; depth, outside, 3 

 inches ; depth, inside, 2^ inches ; breadth, outside, 6J inches ; 

 breadth, inside, 4 inches. 



The average period for construction is about six days— -the 

 longest period, fifteen days and the shortest, three days. The 

 weather and whether the female is pressed to drop her eggs 

 seem to be the chief explanation of the variation- in time. Both 

 sexes build, but the bulk of the work is done by the female. 

 After a nest has been finished, there is often, in fact generally, 

 a delay of from one to four days before laying. 



Laying and Incubation. 



As far as my observations go, one egg is laid each twenty-four 

 hours until the complete set is finished which consists of from 



