Jan. ,1917 



FURTHER NOTES ON THE WHITE-THROATED SWIFT 



new throughout and. were being used for the first time. No. 3 was larger in 

 all dimensions than any of the other nests and there seemed to be at least two 

 layers under the nest in use, and in the layer directly under the new nest the 

 remains of eggs could be seen. It is my opinion that the nest had been used in 

 at least two former seasons. The two lower layers were not substantial, prob- 

 ably having decomposed due to age and insects. Photos of set no. 2 and set no. 

 3, with nests, show difference in size and at the same time the general appear- 

 ance of typical nests. 



Nests are constructed, for the most part, of chicken feathers and grasses 

 cemented together and to the rocks, probably by saliva. They vary in size to 

 suit the space between the walls of rock and are usually shallow and narrow. 

 The following dimensions, in millimeters, show the range of variation. 



Fig. 2. White-theoated Swift, set xo. 3. Note large size of this xest as 



COMPARED WITH XO. 2, AND THE SPOTTED CONDITION OF THE EGGS. 



Nest for 





Outside 





Inside 





Set No. 



Depth 



Length x Breadth 



Depth 



Length x Breadth 



1 



51 



89x63 



25 





63x57 



2 



63 



140x48 



38 





70x41 



3 



57 



146x76 



38 





102x57 



4* 



70 



107x52 









5 



51 



102x51 



19 





70x44 



*Measurements by H. S. Swarth, Museum of Vertebrate Zoolog-y. 



Both the vertical and the horizontal cracks are used as nesting sites, bur 

 with the exception of set no. 5 all that I took were from vertical cracks. It is 

 almost impossible to take nests from horizontal fissures without destruction of 

 the eggs and in the exception noted, a rock weighing at least 35 tons was re- 

 moved. This can be seen in the photo. The location of set no. 6 was rather un- 

 usual, being reached by going into a vertical crack about three feet, then up 

 eighteen inches, then to the side about eight inches. 



