Contest Asymmetry and Multiple Bird Conflicts during Foraging among Nonbreeding American Flamingos in Yucatan, Mexico

Aggressive behavior of feeding American Flamingos (Phoenicopterus ruber ruber) was observed to determine asymmetries associated with contest outcomes. The size difference between male and female flamingos appeared to be the primary determinant of contest roles in two-bird interactions, but contest intensity increased with a reduction in the relative difference in size of the contestants. Multiple bird interactions (i.e., >2) were never initiated by more than two birds, and all identifiable age and sex classes were represented among birds winning and initiating interactions. The large number of adult maleadult female groups involved in multiple bird interactions suggests that some degree of pair bonding had occurred and that mate competition may also be occurring in aggressive interactions in foraging aggregations.