Endocrinology shadows ecology: Characterization of Markhor (Capra falconeri heptneri) reproductive cycles through non-invasive hormone assessment

Abstract

Markhor (Capra falconeri) is a charismatic, threatened, large, high-altitude bovid found in parts of central and south Asia. The species faces threats such as habitat loss, hunting, poaching, livestock competition, hybridisation, and disease, yet research on wild populations is challenging. Various biological aspects, including surveys, diet, population dynamics, interactions with livestock, hybridisation, and disease, have been studied locally, along with behavior and reproductive biology, but details such as pregnancy, oestrus, and parturition timing remain unestablished. We conducted the first systematic, detailed, and fine-scale characterization of the reproductive steroid profiles of two males and five female markhors (Capra falconeri heptneri) in a captive population at the Padmaja Naidu Himalayan Zoological Park (PNHZP), West Bengal, India. We collected weekly fecal samples, standardized and validated measurements of progesterone (fP4M) and testosterone (fTM) metabolites, and conducted reproductive profiling to assess reproductive stages in both sexes. Analyses of annual fP4M and fTM data from male and female markhor individuals showed similar profiles and synchronicity, with individual variation, and peaks and baselines were evident for both hormones. In both sexes, significantly higher hormone titres were observed during the sexually active and inactive phases. Non-invasive measurement of reproductive hormones accurately reflected ovarian function in females, helping establish mating, gestation, and parturition timelines in female markhors and determine the breeding season in males. These approaches support husbandry and breeding management by identifying optimal pairing, diagnosing pregnancy, and predicting parturition in both captive and wild populations. When applied correctly, these tools could greatly aid population monitoring of other endangered species across high-altitude regions worldwide.