Annual monitoring of fecal androgens and antler cycle in male marsh Deer (Blastocerus dichotomus)

• Grant number: 24/21271-7
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: July 31, 2028
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: José Maurício Barbanti Duarte
• Grantee: Laís Jaqueline de Souza
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

The Neotropical region hosts a vast diversity of deer species, including the marsh deer (*Blastocerus dichotomus*), a species classified as vulnerable to extinction due to habitat fragmentation and other anthropogenic pressures. To guide management and conservation strategies, a comprehensive understanding of the species' reproductive physiology is essential. However, various endocrinological aspects and the male reproductive cycle remain underexplored or unknown. This study aims to characterize the annual profile of fecal androgens in male marsh deer and correlate hormone levels with antler development and certain environmental factors, in both captive and free-ranging individuals. Fecal samples will be collected quarterly over one year, encompassing a free-ranging population monitored in the Pantanal of southern Mato Grosso do Sul, as well as approximately 20 captive individuals. Samples will be processed and analyzed using enzyme-linked immunosorbent assays (ELISA) for androgen quantification. The results will be statistically analyzed to determine whether mean hormone levels differ between captive and free-ranging individuals and to identify correlations between hormones and antler phases, direct contact with females, and environmental variables such as photoperiod, temperature, and precipitation. This study will provide critical information for the application of reproductive biotechnologies and effective management actions, contributing to the conservation of the marsh deer and the preservation of wild populations.