488 U.S. NATIONAL MUSEUM BULLETIN 23 7 part i 



trend toward stabilization, have tended to attract fewer goldfinches. 



In the spring of 1938, annual plants were abundant and produced 

 a heavy crop of small seeds suitable for goldfinches and other finches. 

 Throughout the season the birds fed on them in large numbers. On 

 the same slopes in the spring of 1955 the annual plants were so dwarfed 

 they produced scarcely any seeds, and no goldfinches foraged there. 



Courtship. — One morning in mid-February a pair of Lawrence's 

 goldfinches lit in the top of a blue oak. The male sang for 2 minutes 

 as he perched 2 feet away from the female. Next, the female flew 

 down a canyon and the male followed. When he came within a foot 

 of her, she would dive, closely followed by the male, and a moment 

 later the two would shoot upward, the male still following closely. 

 The birds flew out of sight in this manner. 



After the middle of March 1938, from 50 to 200 Lawrence's gold- 

 finches were present on the Reservation daily for nearly a month. 

 The large flocks foraged in afternoons on a south-facing slope. At 

 intervals the whole flock stopped feeding and flew off to a fence or 

 to an isolated blue oak where they perched and sang, usually facing 

 into the sun. The birds seemed to be already paired, for the sexes 

 usually perched together in couples. 



Courtship display was observed frequently in April, the males 

 perching near the females and extending the head and neck as they 

 sang. In mid-April a pair of goldfinches perched on a valley oak 

 limb 7 feet above the ground. The singing male sat 6 inches from 

 the female with his head outstretched and feathers compressed against 

 the body. 



By April 24 the goldfinches were clearly paired; the couples kept 

 close together and followed each other. Singing and posturing among 

 the Lawrence's goldfinches on the afternoon of April 26 became more 

 pronounced than earlier in the season. In a flock watched at this 

 season the 20 birds were obviously paired. Ten or more times males 

 flew at other males in efforts to drive them away from a particular 

 female. This was always a Lawrence's driving away another of the 

 same species, except once when a green-backed male was driven. 

 Usually a move of only 5 or 6 feet was required for the pursued bird 

 to avoid another attack. Both birds would then settle on perches. 



At midmorning on May 20 an observer watched a female quivering 

 her wings before a male. The male took no notice, and the female 

 kept fl3ang up to him. On May 22 a male fed an adult female near 

 a nest high in a tree. The quivering wings of the female spread less 

 widely, and they moved less rapidly than the observer had detected 

 in related species. 



In the stage before the start of incubation the members of each 

 pair are strongly attached to each other. The male stays with his 



