1914] Grinnell: Mammals and Birds of the Colorado Valley 201 



was noted all along only in willows or mesquites. Seven specimens 

 taken, nos. 13683-13689. Evidently occurs through the region as a 

 migrant only. 



Dendroica townsendi (Townsend) 



Townsend Warbler 



First noted April 26, on the Arizona side five miles north of Laguna, 

 two seen and another secured. At Potholes, April 28 and 29. fully 

 twenty-five were noted ; four miles south of Potholes May 2 one was 

 taken, and another five miles northeast of Yuma. May 4. In the vic- 

 inity of Pilot Knob several were seen May 13 and 14. At every other 

 place the birds were exclusively in the willows, but here they were in 

 arrowweed as well. Evidently a transient. Nine specimens taken, 

 nos. 13690-13698. 



Dendroica occidentalis (Townsend) 



Hermit Warbler 



First observed, a male, April 20, on the California side, eight miles 

 east of Picacho ; next, a male, on the Arizona side five miles north of 

 Laguna. April 25 ; then at Potholes on the 28th and 29th. several ; 

 five miles northeast of Yuma, May 3, a male; and near Pilot Knob. 

 May 9. a female. A through migrant. Six specimens taken, nos. 

 13699-13704. 



Oporornis tolmiei (Townsend) 

 Tolmie Warbler 



First noted, a male, April 12, on the California side of the river, 

 twenty miles north of Picacho. Next observed, in numbers, both sexes, 

 April 25 and 26, on the Arizona side five miles above Laguna. Then, 

 on the California side, almost daily in varying numbers, at Potholes. 

 four miles below Potholes, five miles northeast of Yuma, and in the 

 vicinity of Pilot Knob. The species was still common in the latter 

 locality. May 14. 



In all the above places, the species adhered closely to the arrow- 

 weed and quailbrush associations, frequently visiting the water's edge 

 through the willows, especially during midday. The brush associa- 



