Maned wolf pair Echo and Zayda have finally welcomed their first pups at Smithsonian's National Zoo. Female canids have only one estrous cycle a year with a five day window to conceive, which makes successful captive breeding efforts vital. But incredible research at the Cornell-Smithsonian Joint Graduate Training Program, where the first in-vitro fertilization in a domestic dog was recently successful, is making that process easier. Learn more about this scientific breakthrough and the threatened wolves it will one day help protect.