GREEN-BACKED GOLDFINCH 481 



stomach was entirely filled with these insects, and in another 300 

 were counted. 



Peterson (1942) offered salt to birds in a partly wooded pasture on 

 the side of Mount Diablo. The green-backed goldfinches came in 

 flocks and covered the salt-saturated ground, feeding mostly from 

 the earth within a foot of the salt block. 



Drinking. — These birds apparently need large amounts of water to 

 help digest the seeds they eat. Availability of water is important in 

 the nesting season, and later when it becomes scarce, its distribution 

 determines where the goldfinches live. In the dry seasons they con- 

 centrate about streams and springs. 



Mrs. Edwards (1925) has described the behavior of goldfinches at 

 a bird bath. A flock of more than 50 birds crowded over a trap and 

 the water below it, chirping cheerily. WhUe the captives were re- 

 moved from the trap, the rest of the flock remained at and around 

 the far end of the trap, not 2 feet away. E. D. Clabaugh (1930) 

 reported that in his bird banding, green-backed goldfinches were 

 captured only by using water as bait. He used both the warbler and 

 Potter traps, usually with water dripping into the trap in some manner. 



On Sept. 6, 1939, the overflow pipe from a weU led to a barrel set 

 on a creek bed under a red willow. The water pouring into it filled 

 the barrel and overflowed so that one edge was wet and the other 

 was dry. After a few minutes many goldfinches in the surrounding 

 willows began to come to the barrel to drink, unlike the juncos which 

 drank from the creek bed. The first one lit on the wet edge, followed 

 in a few seconds by two more, and finally eight were lined up drinking 

 before the first ones started to fly off. 



The next morning goldfinches in some coast ceanothus were at- 

 tracted by an overflow of water. As many as 13 stood and drank in 

 the running water within a radius of 1 foot. When frightened they 

 flew into the ceanothus, then went downhill 10 yards, and reassembled 

 at the water to drink again in a compact group. One afternoon when 

 20 were drinking, something frightened them, and they all flew off 

 into the nearest trees, except one which remained and continued to 

 drink; this doubtless encouraged the immediate return of the others. 



At midmorning on Jan. 10, 1954, at the Hastings Reservation, a 

 flock of juncos and goldfinches visited a water trough where the water 

 was covered with ice. The ice melting at one corner formed a small 

 pool where two goldfinches drank. A male goldfinch stood on the 

 ground beneath one corner, ruffled its feathers, and tried to bathe. 

 An hour later when the surface ice had melted the flock returned to 

 the trough and many of the birds drank. 



Bathing. — At noon in early January nine goldfinches, calling con- 

 tinuously, bathed in shallow water in a creek. Each bird stood in 



