Red foxes are often monogamous, but polygyny can occur with one breeding male and several breeding females all sharing a den.
Red fox mating behavior varies substantially. Red fox groups always have only one breeding male, but that male may also seek mating outside of the group, known as polygyny. Often, males and females are monogamous, but males with multiple female mates are also known, as are male/female pairs that use non-breeding female helpers in raising their young.
Females mated to the same male fox may share a den.