Human fathers get plenty of recognition on Father's Day—celebrated this year on June 16. But the animal kingdom also has its share of committed dads.
Take male owl monkeys (pictured, a zoo adult and baby in 2009), which appear to perform most of the duties in rearing their young. (Watch a video of owl monkey fathers and their babies.)
These South American monkeys form lifelong partnerships with their mates. The father transports and grooms the babies, while the mother takes care of nursing, according to research by Eduardo Fernandez-Duque, a biological anthropologist at the University of Pennsylvania.
According to Mark Pagel, an evolutionary biologist at the University of Reading in the U.K., "These strong pair bonds—what we often call monogamy—normally only evolve where the ecological conditions mean that both parents are needed to acquire enough food and provide enough protection to ensure offspring survival.
"So 'best fathers' often seem to arise from ecological necessity!"