Prosocial behaviors, including empathetic consoling toward others, contribute to maintaining social groups and social connections between individuals in many mammalian species, including monogamous prairie voles (Microtus ochrogaster). Prairie voles display consolation toward distressed partners by increasing allogrooming behavior toward the partner. A previous pharmacological study showed that oxytocin signaling contributes to consolation in male prairie voles, although possible sex differences in the regulation of consoling have not been explored. Here, we demonstrate that male, but not female, oxytocin receptor knockout (Oxtr