POINT PINOS OREGON JUNCO 1085 



Another possible extension is reported by A. H. Miller (1945), 

 who writes concerning the collections of the late O. P. Silliman: 

 "Two juncos * * * taken on July 7 and 8, 1937, at San Ardo, 450 

 feet, Monterey County, seem to indicate a breeding station for the 

 race pinosus in the floor of the middle section of the Salinas Valley; 

 one of the birds was molting. This is an unexpected local extension 

 of the breeding range of this race which nests commonly at higher 

 elevations in the mountains on either side of the valley." 



Spring. — In the mild climate of this part of California the breeding 

 activities of the resident juncos are much advanced over those of the 

 migrants present as winter visitants. The migratory races face 

 spring flights of varjang lengths; the resident juncos are near or 

 actually on their breeding territories, and they behave accordingly. 



Grinnell and Linsdale (1936) say: "We soon noticed on our winter 

 trips that the resident birds seemed to be paired and the flocks seemed 

 to be made up mainl}^ of winter visitants and transients. The pairs 

 were stationed on the type of ground where the birds later nested 

 and they behaved often as if they were defending the sites against 

 invasion. This situation was detected as early as December [1934] 

 and it was plainly evident by the middle of February [1935]." 



In the experiments Albert Wolfson (1942) made on resident and 

 migrant Oregon juncos, mentioned in the main species account 

 (page 1053) , the resident juncos he used were pinosus. He found that 

 although the different races flock together in winter in the same 

 environment, the residents and migrants show marked differences in 

 their gonadal cycles: "The testes of the residents recrudesce earlier 

 and at a faster rate than those of the migrants." Because of the 

 energy migrants need for their spring flights: "In the migrants 

 there is a heavy deposition of subcutaneous and intraperitoneal fat 

 at the time of migration. The residents show no such deposition 

 of fat." 



Grinnell and Linsdale (1936) write: "Definite evidence of the begin- 

 ning of the nesting season was seen on March 20 [1935], a cold, cloudy 

 day when a pair in copulation was seen in a patch of monkey flower 

 on the floor of the pine woods." They continue: "On March 24 

 [1935] nearly all of the juncos seen were definitely in pairs and scat- 

 tered mainly through the pine woods. The birds spent most of the 

 time sitting quietly on perches in the trees. Tliey fed largely in the 

 trees, but about one-third of the time on the ground. Occasionally 

 one or both birds of a pair would indicate excitement by spreading 

 tlie tail and trilling, but this was followed by another quiet period. 

 There was some singing — often 3 or 4 birds could be heard at 

 once in different directions, but the locations of singing birds were 

 hard to determine." 



