GREEN-BACKED GOLDFINCH 435 



bird made a sound. Later that month a sparrow hawk dived at a 

 goldfinch perched in the top of an oak; the goldfinch escaped down 

 inside the crown of the oak, leaving the hawk perched in the top. 

 The evening of June 8 a pigmy owl flew by with a green-backed 

 goldfinch, apparently a juvenile, in its talons which it had caught 

 near a water trough that regularly attracted many goldfinches, 



A flock of 50 goldfinches chattering in a live oak at the end of 

 January momentarily became quiet as a screaming scrub jay came 

 by. Early in the morning of May 25 a scrub jay flew to a limb 4 

 inches from the nest of a green-backed goldfinch. Both male and 

 female goldfinches flew about the jay from different directions, not 

 approaching closer than 8 inches, until the jay left. Having discov- 

 ered the nest the jay returned later in the morning and repeatedly 

 drove its bill into the side of the nest until it was demolished. 



Plath (1919), in his studies on nestling birds at Berkeley in the 

 summer of 1913, found 8 of the 1.3 goldfinch nests examined infested 

 with maggots of Proiocalliphora azurea (Fallen) (Apaulina). In one 

 nest of young green-backed goldfinches all the nestlings died. Com- 

 pact nests such as goldfinches build showed a greater infestation than 

 loose-textured nests such as those of the brown towhee. 



A. W. Anthony (1923) found Argentine ants {Iridomyrmex humilis) 

 in San Diego, Calif., swarming over recently abandoned nests of 

 green-backed goldfinches. In the same area he found a goldfinch 

 less than a week old that he thought had been taken from the nest by 

 the Brewer's blackbird that was vigorously pounding it. In Santa 

 Clara County, W. L. Atkinson (1901) found two green-backed gold- 

 finches that a loggerhead shrike had impaled on a barbed wire fence. 

 Green-backed goldfinches were among the birds destroyed during 

 fumigation of orange trees (A. B. Howell, 1914). Edwards (1919) 

 found newly hatched goldfinches dead under a tree after a wind storm. 



Fall. — In early August 1939, the goldfinches on the Reservation 

 were usually paired or in small groups; evidently some families were 

 still united. Perhaps the adults remained paired after nesting while 

 the yoimg congregated in flocks. On September 1 the goldfinches 

 were not numerous in the morning; only two flocks were observed in 

 half an hour and those contained less than 20 birds each. Formerly, 

 from 50 to 100 birds were in evidence. Two days later groups of 5 to 

 15 went to a tank overflow, but did not remain long, the early rains 

 having removed the need to remain in its vicinity for long periods. 

 In mid-November of one year 15 green-backed goldfinches perched 

 in the tops of oaks at the edge of chamise at the summit of a hill. 

 There was much singing as the clouds broke, but the birds became 

 silent when a drizzle began. 



