Anciaes et al. • NESTING OF YELLOW-OLIVE FLATBILLS 
553 
B 
E 
Age (days) 
FIG. 4. Growth curves derived using the logistic model. (A) body mass. (B) wing. (C) tarsus. (D) tail, and (E) bill for 
nestling Yellow-olive Flatbills. 
eggs (Martin 1987). Alternative hypotheses for 
large clutch sizes include increased adult mortal¬ 
ity and reduced predation risk associated with 
short incubation periods, typical of northern 
latitudes (Martin 1995. 2002). These hypotheses, 
however, are directed at explaining breeding 
differences between temperate and tropical re¬ 
gions in response to selective forces operating at a 
