Using behavioral observations and genetic markers to characterize the flexible reproductive system in an ex situ population of carmine bee-eaters (Merops n. nubicus)

Combining behavioral observations with population genetic analyses in ex situ populations can be used to evaluate factors that determine the success of a breeding program. Avian species living in a colony accrue reproductive benefits by taking advantage of multiple reproductive strategies. Growing evidence suggests that both extra pair fertilizations (EPFs) and intra-specific nest parasitism (ISNP) are sufficiently frequent in colonial birds to produce patterns of relatedness that differ from those inferred from behavioral observations. The aim of this study was to use behavioral and genetic information to examine relatedness and reproductive behaviors in an ex situ colony of Northern carmine bee-eaters (Merops n. nubicus). We conducted behavioral observations to determine social parents (i.e. the males and females that entered/exited each nest with the highest frequency). We also used microsatellite marker to conduct parentage analysis and calculate relatedness between individuals in the colony. Using two methods of parentage analysis, we were able to determine one or both parents of all offspring. Males and females differ in their parental behavior during the different reproductive phases. Finally, both males and females were found to use reproductive strategies other than monogamy. In general, EPFs and ISNP are two of the consequences of social living, with multiple individuals utilizing these various strategies for reproduction. In summary, our study found that Northern carmine bee-eaters use a flexible social system that enables individuals within populations to take advantage of suitable nest conditions and mating strategies as they arise, which allows for some individuals in this ex situ colony to have improved reproductive success.