| Campylorhynchus (Troglodytidae) is a variably social genus ideal for study of environmental influences on evolution of cooperative breeding. I studied the social breeding system of the Yucatan Wren ( C. yucatanicus) in 2011 and 2012 as the first field study of the species with uniquely marked individuals. Results included the first quantified rates of cooperative breeding in this species (9-27% of groups ≥ 3); even nestling sex-ratio; and high adult survival rate (73%), independent of sex or helper presence. Male-bias helpers were not retained between years; males were 7.5% larger than females by mass overall and less likely to disperse. In comparison to previous studies, I report substantially different nest substrate, similar clutch size, and higher ectoparasite rate . Overall, C. yucatanicus exhibits high nest success (54% of all nests) for a non-cavity-nesting tropical passerine, fits in the decreasing latitudinal pattern of Campylorhynchus nest success, and occasionally breeds cooperatively Data from this study expands our knowledge of natural history within Campylorhynchus and cooperative songbirds in general. |
