Female mate choice significantly increases captive breeding success, and scents can be frozen to determine choice, in the stripe-faced dunnart

Devising non-invasive techniques to maintain natural behaviours and increase breeding success of captive populations is a high priority in the conservation of endangered species. Allowing animals to choose their own mates not only preserves behaviours that are essential for successful release and re-establishment of wild populations, but could increase the number and genetic quality of young and genetic viability of a population. It can also decrease stress and aggression between mates and reduce the likelihood of fighting, injuries and deaths. Despite this, mate choice often remains underused in captive breeding programs. Additionally, the use of freezing and storing scents to determine a female’s mate choice between institutions has not been examined. We examined the effects of familiarity between mates, male age, preferences of relatives, and freezing scents on female mate choice and breeding success in a colony of a small marsupial, the stripe-faced dunnart (Sminthopsis macroura). Experiments were conducted using olfactory cues from males placed in the female’s enclosure. Pairings based on mate choice resulted in significantly more pregnancies per female and per oestrus cycle (p = 0.001), and a shorter time to parturition (p = 0.017), than females paired on pedigree alone, though there was no significant difference in litter sizes (p = 0.380). Familiarity between mates did not affect female preferences (P > 0.50), but significantly decreased levels of aggression and minor injuries between mates (p = 0.042). Male age similarly did not affect a female’s preference (P > 0.18). Females paired with the choice of their sisters had high breeding success (73.7%), suggesting that mate choices can be applied to related animals. Freezing a male’s scent for up to 40 days at −20 °C did not affect female choice and may be used for enabling mate preference between captive breeding institutes. The results show that female mate choice can significantly increase breeding success in a captive marsupial breeding colony and may be a powerful tool for a variety of endangered species breeding programs.