The canid family (dog-like animals) is unique among mammals due to their reproductive biology. As opposed to other mammals, females in this family only cycle once every year.
Social strategies within the family Canidae range from solitary to highly social. Thus, Canidae presents an interesting family in which to study communication regarding reproduction.
Studies designed by researchers at the Smithsonian Conservation Biology Institute aim to illuminate how males and females maned wolves communicate about their reproductive status. These studies will make it possible to improve captive management strategies for this threatened species, leading to enhanced breeding success in zoos, and a healthy captive population as insurance against extinction in the wild.
The maned wolf is a unique canid found mainly in Brazil, but also across parts of Argentina, Bolivia, Paraguay, and Peru. Habitat loss due to agricultural development threaten smaned wolves.. Unlike other large canid species, the maned wolf is monogamous but solitary. Mates defending a shared territory, but only rarely interact. Female maned wolves are receptive to mating only for about one to ten days every of the year. Considering the short period of receptivity and the large size of the maned wolf’s home range (up to 31 square miles or 80 square kilometers), long-range communication about reproduction is especially important.
Our recent studies indicate that maned wolves are induced ovulators, which means females ovulating when a male is present. Research suggests that ovulation is regulated by olfactory signals (scents) rather than by visual stimuli or by physical contact. Specifically, when females are housed next to a male they can’t touch, but can access his scent marks, ovulate while females who could only see a male but couldn’t investigate his scent marks, did not.
Previous studies have shown that as breeding season approaches, maned wolves scent mark more frequently, which suggests that there are signal compounds in their urine rather than in feces or glandular secretions.
Ongoing studies are exploring volatile chemical constituents in maned wolf urine, specifically searching for compounds that differ between males and females, from season to season, and/or with the onset of puberty. Once isolated, these compounds will be present to wolves to determine their physiological responses to such chemicals.
Smithsonian researchers are developing artificial insemination techniques in maned wolves, which hinge upon the ability to induce ovulation. Currently, researchers manipulate maned wolf reproductive hormones with hormone therapy, requiring multiple anesthetizations. We hope that discovering more about how ovulation-induction works will lead to a method of naturally priming females for artificial insemination. This research will build the foundation for enabling ovulation-induction without the use of anesthetic drugs, considerably easing captive management while improving animal welfare.