In a remarkable milestone for wildlife conservation, a new fawn named Clemente was born on May 23, 2025, at the Instituto de Investigaciones Biológicas Clemente Estable (IIBCE) in Uruguay. Clemente's birth is especially significant as he is the first Brazilian field deer (Ozotoceros bezoarticus) conceived through assisted reproduction in the country, marking a hopeful step towards saving this endangered species.
The day was not ordinary; it coincided with the birthday of the institute's namesake scientist and the National Science and Technology Day in Uruguay. For Susana González, who leads the Biodiversity and Genetics Department at IIBCE, the moment was filled with excitement and relief. “We really didn't think he would survive,” she admitted. The gestation period had surpassed the usual seven and a half months, leaving the research team apprehensive, especially considering the challenges of determining pregnancy in wild deer. “When I received the announcement of his birth that day, it felt perfect, but I worried that the cold might be too much for him. Thankfully, he survived and is doing well.”
Clemente's story is not just about a successful birth; it embodies an ambitious scientific endeavor aimed at safeguarding a species facing severe decline in Uruguay. His conception was made possible through artificial insemination, utilizing preserved semen from a male deer from Salto and inseminating captive females at the Fauna Autóctona Breeding Station in Pan de Azúcar, Maldonado. The Ministry of Education and Culture has recognized this as Uruguay's first documented successful case of assisted reproduction for this species.
Despite the harsh winter conditions that raised concerns among the technical team about the timing of the procedure, the outcome exceeded expectations. Clemente was born larger than the average fawn and swiftly began eating a balanced diet while nursing from his mother. “He looks great and is larger than typical fawns, which is a positive sign. He is already eating solid food but still enjoys nursing," González shared. Clemente is currently housed with the other females in the study, and early signs indicate a healthy and promising development.
The project involved the preparation of ten females for insemination, but not all could participate due to health issues. Currently, there are eight females remaining in the program. "It’s essential to keep them in familiar groups because changes in their environment can be stressful," González explained.
This initiative encompasses reproductive biology and population genetics techniques that are not isolated cases. González and her team are developing genealogies for the donor males and participating females to enhance genetic diversity—a crucial element for successful conservation efforts. “We aim to create a pedigree to better manage genetic variability, which is essential for establishing a sustainable population in the long run," she emphasized.
One of the challenges the team faces is creating semi-captive conditions that mimic the animals' natural behavior. Capturing or handling them for checks can be stressful due to their instinct to hide and flee. "They're used to wide pastures, and if you try to catch them, they become elusive. This complicates our work, but it’s important for maintaining conditions that reflect their natural habitats," González noted.
The project has garnered international support, with funding from the Whitley Fund for Nature, and González is hopeful about applying for the prestigious Whitley Gold Awards, which provide funding for two years. "It's a very competitive process; only one is awarded each year. But if we can secure just one funding opportunity, we can continue our work for another year," she said.
Cecilia Ferrando, a master's student, has recently completed the hormonal data collection from the females, and the next steps involve analyzing this information and planning further interventions for 2026 or 2027.
The Brazilian field deer is one of Uruguay's most iconic yet threatened species. Over the centuries, its habitat has drastically shrunk due to land conversion, hunting, and agricultural expansion. Just 300 years ago, these deer were considered abundant—now, they are critically at risk.
“In a study conducted with researchers Mariana Cosse and Brazilian biologist Mauricio Barbanti, we fitted ten individuals with radio collars, but only three survived the two-year study. Most did not make it that long for reasons we still don't fully understand. In the wild, they could potentially live between 8 and 12 years,” González revealed.
In captivity, the life expectancy can improve due to health monitoring, nutritional support, and constant care. “Veterinarian Hugo Arellano checks on them daily, ensuring any health issues are addressed immediately. Regular parasite control has shown the animals have good immunity,” noted González.
Clemente represents more than just a healthy fawn; he symbolizes the practical application of science in preserving native species. He stands as a living testament to collective effort, rigorous research, and a hopeful belief that knowledge, alongside supportive public policies, can reverse the silent extinction of a species that once roamed Uruguay's grasslands freely.