528 TlIRUfcHES. 



April. Song, the most finished of that of 

 all our birds. There are four strains: 1, Oh 

 tivee twee twee, clear and high; 2, E. twter 

 twter twter, lower but pure; 3, Oh phera 

 phera phera, lower in tone almost pathetic 

 in terminal note, all prolonged; 4, E. che te 

 wete, softly given, often whispered. The 

 above is the order in which the complete" 



Fig. 417 



Blue-gray Unatcatcher. 1-4. 



song is given, but strains are frequently 

 omitted. Alarm, a whistled chuck. Fre- 

 quents woodlands. Nests on ground; eggs, 

 unspotted. 



604. OLIVE-BACKED THRUSH. 



Differs from last in being uniform olive 

 above, strongly tinged on head and eye-ring 

 with rufous, spots beneath broadly trian- 



