298 LIFE-HISTORIES OF BIRDS 



which is succeeded by a very fine trill pitched in a 

 very high key, and sung crescendo. The following 

 syllables will give an approximate idea of its ex- 

 pression : — twed-iwed-twed-twliinu-inii occasionally 

 varied by iwl-twl-twi-tur-r-r-r, twilliii-tiofi. Its 

 ordinary call is a simple twi produced at irregular 

 intervals. 



In the spring it deserts our yards and orchards, 

 and frequents waste grounds and the borders of 

 open fields and thickets, where it prefers a life of 

 solitude. It how discards its former associates, 

 and higher considerations engross its mind and 

 attention. » 



It disappears during the latter part of April for 

 its more northern habitat. We have met this 

 species in all the months except July and August, 

 and are certain that it does not breed within, the 

 limits of Philadelphia. The Tree Sparrow breeds 

 in high Arctic regions. Mr. Kennicott found its 

 nest on the Yukon; Mr. Dale at Nulata; and Mr. 

 MacFarlane in vast numbers at Fort Anderson. 

 According to the last, authority the nests are 

 mostly placed upon the ground, some few on small 

 bushes, and only one being recorded as having 

 been placed several feet above it. One occupied 

 the cleft of a low willow, another was placed 

 within a bUsh at an elevation of nearly four feet 

 above the ground, while a third was but" fourteen 

 inches above the ground in a clump of willows; 

 nearly all the others were posited directly upon 

 the jrround. ' '•. 



