Patterns of ovarian and luteal activity in captive and wild Canada lynx (Lynx canadensis)

Canada lynx face some unique breeding restrictions, which may have implications for population viability and captive management. The goal of this study was to improve our understanding of basic reproductive physiology in Canada lynx. Using fecal hormone metabolite analysis, we established normative patterns of fecal estrogen (fE) and progestagen (fP) expression in captive and wild female Canada lynx. Our results indicate that Canada lynx have persistent corpora lutea, which underlie their uncharacteristic fP profiles compared to other felids. Thus, fP are not useful for diagnosing pregnancy in Canada lynx. We also found that Canada lynx are capable of ovulating spontaneously. Captive females had higher concentrations of fE and fP than wild females. Both populations exhibit a seasonal increase in ovarian activity (as measured by fE) between February and April. Finally, there was evidence of ovarian suppression when females were housed together.

Research highlights
► Canada lynx are capable of spontaneous ovulation.
► Corpora lutea may persist for an unusually long time.
► Captive females have higher fecal estrogen and progestagen levels than wild females.
► Group housing of females may contribute to ovarian suppression.