Mery (1966) showed an almost equal sex ratio, males returned more frequently than females, over 50% of returns paired with other returns, an adult return rate of 20%, and no pair bonds maintained for more than one season. Her study lasted 13 years. Our study has shown that the return rate of locals to parent colonies is 4.1%, sex ratios are nearly equal (combination of banding and observation), return rate of locals to nearby colonies is 0.9,one pair maintained the pair bond for two years, SY females lay fewer eggs than ASY's, SY adults occasionally do not feed frequently enough to maintain the normal growth pattern of the young, SY adults often build poorly constructed nests with little or no mud, overall nest success is lower in SY adults, adults do indeed return to the same colony (19.6%) box and/or compartment, sexes are balanced in a stable colony, males or females are sometimes in excess in a new colony, SY adults are predominate in a new colony, the limiting factor in colony size is most likely the number of boxes and/or compartments available for nesting and,finally, adults and young do indeed use the boxes for roosting after nesting and fledging is complete (even boxes not their own). All of our results are tentative and subject to change after f rther study. Much additional study will be required before we can come up with conclusive answers to many of these questions about the Purple Martin.
Additional Publication Details
A new banding technique for nesting adult purple martins