The role of male parental care in monogamous Hill Mynah (Gracula religiosa)

Little is known about the selective pressures driving monogamy in the Hill Mynah (Gracula religiosa). Thus, this study investigated the male's role during reproduction to understand the evolutionary advantages of the monogamous mating system. Experiments were performed on captive birds in Thailand from 2012-2015. In the first experiment, I recorded allopreening and nest-entry frequency/duration from both parents during three periods: nesting, incubation, and feeding of offspring. Females preened their mates significantly more than males did. Moreover, female allopreening was significantly correlated to male parental care (as indicated by nest-entry data), especially when nestlings were 1-20 days old. In the second experiment, males were removed from various nests either when incubation began or when nestlings were 1, 11, or 21 days old. Solitary females were significantly less successful at incubating and raising young, which also weighed less than broods from biparental nests. Therefore, male parental care is likely required for nestling survivability and reinforces monogamy in the Hill Mynah.