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The Maned Wolf Project

Marieke Kester


The maned wolf project is a collaborative project between the Smithsonian Conservation Biology Institute in Front Royal, VA and George Mason University’s Shared Research Instrumentation Facility.  The study’s goals are to use GC-MS to identify urinary compounds possibly involved in olfactory reproductive communication in the maned wolf and then to use bioassays to test suspected pheromones using behavioral studies of the maned wolf.

Maned wolf Background
The maned wolf is a unique canid found mainly in Brazil but also across parts of Argentina, Bolivia, Paraguay, and Peru.  The species is threatened by habitat loss due to agricultural development.  Unlike other large canid species, the maned wolf is monogamous but solitary, with mates defending a shared territory but interacting infrequently.  Female maned wolves are receptive to mating for only 1-10 days out of the year.  Considering the short period of receptivity and the large size of the maned wolf’s home range (up to 80 km2), long-range communication about reproduction is especially important for this species.

Recent Research Developments
Recent studies by the Smithsonian Conservation Biology Institute indicate that maned wolves are induced ovulators, with females ovulating only in the presence of a male.  Research suggests that ovulation is regulated by olfactory signals rather than by visual stimuli or by physical contact.  Specifically, females housed adjacent to a male with no direct physical contact but access to his scent marks ovulated, while females housed diagonally from a male with only visual contact (no ability to investigate scent marks) failed to ovulate.  Additionally, previous studies have shown that as breeding season approaches, maned wolves scent mark more frequently, suggesting the presence of signal compounds in urine rather than in feces or glandular secretions.

Urinary Analyses
Studies at SRIF are exploring volatile chemical constituents in maned wolf urine using GC-MS, specifically searching for compounds that differ between males and females, compounds that differ seasonally, and compounds that differ with the onset of puberty.  Once isolated, these compounds will be used in bioassays to determine their role in reproduction.

Natural Induction of Ovulation
Smithsonian researchers are developing artificial insemination (AI) techniques in maned wolves, which hinge upon the ability to induce ovulation.  Currently, researchers manipulate maned wolf reproductive hormones via hormone therapy, requiring multiple anesthetizations. Discovering more about how the natural system of ovulation-induction will hopefully lead to a method of naturally priming females for AI.  This research will build the foundation for enabling ovulation-induction without the use of anesthetic drugs, considerably easing captive management while improving animal welfare.

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photo credit: Amy Johnson, SCBI


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