/6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I43 



dividual montane bush flock was usually watched continuously for a 

 considerable length of time (usually 15 minutes to 1 hour). In com- 

 piling table 45, a bird was considered to have joined another (or sev- 

 eral others) when it approached within 10 feet of another, or others, 

 without continuing to move after the others, and without forcing the 

 others to move away. The joined birds were usually more or less 

 stationary before being joined. A bird was considered to be following 

 another (or others) when it hopped or flew steadily after the others, 

 while the others were moving themselves. 12 Supplanting attacks were 

 recognized by the same criteria as in the counts of similar reactions in 

 mixed blue and green tanager and honey creeper flocks. 



Table 45. — Interspecific following, joining, and supplanting reactions involving 



some species of the montane bnsh alliances in some higher-altitude mixed 



flocks observed between October 4 and 10, i960 



£ 



B 3 G «o B CjUtn 



wo £ B to „„co co « v ai o (0 m tojj o 



<0 to O m g <o-£.H »S.S ") £ g- to 13 g »M«i to "Eg 



ag-g g.a Ejgg g.cg 5=353 §!•. 6~g ||„ 



■*lT3 £ <C.H "Jo 01 -J3 « *3«5 j ~-°_g « 3 « « ~ S 



o«- £ ofe o B i> oCm oc° ono o»o o c o 



° to O iaO ,2,0.0 2-3ja ►£ to O ,2.0.0. 



''•JE E °t* O B i> O S D O R ° OCO w n. •» 



j G S ofi no*, o <u ■" o S> £• oS J o 



£5.5 g.5 I 0,0 ^too ^** ^.0.0 ^ 



Brown-capped bush- 



tanager 37 n 3 2 18 19 o 1 



Yellow-thighed finch . . . 33 16 22 7 10 6 o o 



Red-faced spinetail 4 2 10 12 1 o 



Silver- throated tanager ..15 7 o 2 o o 1 3 



Wilson's warbler 31 31 15 7 3 o o 1 



Collared redstart 16 10 3 9 6 o o 



Table 45 is a list of all the interspecific joining, following, and 

 supplanting reactions observed, including ambiguous cases when one 

 bird joined or followed a group composed of individuals of several 

 other species. The figures in this table are not strictly comparable 

 with the counts of interspecific reactions in mixed blue and green 

 tanager and honeycreeper flocks shown in the preceding tables. The 

 reactions of each species are listed separately in the table, without 

 attempting to identify the other species involved in any given reaction. 



Many of the higher-altitude mixed montane bush flocks seem to be 

 formed in much the same way as all or most mixed blue and green 

 tanager and honeycreeper flocks (but see also comments below). Like 



12 All the joining and following reactions cited in the subsequent discussion 

 of the usual social roles of different species in mixed montane bush flocks were 

 distinguished by the same criteria as in this count. 



