A female of the Serra Saki species (Callithrix flaviceps), which is classified as critically endangered, gave birth to triplets on the 25th within the Serra Saki Conservation Center (CCSS), belonging to the Federal University of Viçosa (UFV), located in Minas Gerais. This event is considered unusual, given that females of this animal usually give birth to only two offspring per gestation.
The conservation program dedicated to the Serra Saki, which began in 2025 and is conducted by UFV, is the only one in the world managing and breeding this species. Professor Fabiano Melo, known as Bião, leads the team and clarifies that the mother of the triplets is part of one of the groups monitored by researchers.
This assisted reproduction program aims to ensure the continuity of the Serra Saki, which is listed as critically endangered by both the International Union for Conservation of Nature (IUCN) and the national list of threatened species. The main threats faced by the species include forest fragmentation, loss of its natural habitat, and genetic hybridization.
Bião Melo details that the female already had offspring from a previous gestation, who are now young. After becoming pregnant again, she gave birth to three live pups. He adds that the survival of the third pup is quite challenging without the collaboration of the older members of the group, as sakis have a social structure where the father, brothers, and sisters help care for the newborns. Currently, the three pups are in good condition.
According to Bião Melo, the reproductive period coincides with the rainy season, occurring from October onwards. The pups usually are born in October, November, and December, with a possible last litter in January and February, although October and November are the most frequent months.
The Serra Saki is endemic to the Atlantic Forest, found in eastern Minas Gerais, the mountainous area of Espírito Santo, and the extreme north of Rio de Janeiro. Its distribution covers altitudes ranging from approximately 200 meters, in the Vale do Rio Doce region, up to locations above 1,200 meters in Espírito Santo. In addition to the triplets, four other pups were born under human assistance at CCSS in October 2026. Two females from the same group became pregnant by the same male, who had been separated previously to promote greater genetic variability in future reproductions.
CCSS is the only place responsible for this type of work. When the Serra Saki population is expanded, the intention is to distribute animals to other institutions dedicated to primate conservation. Bião Melo explains that by increasing the number of animals, they will be distributed to other breeding centers, aiming to strengthen the safety population under human care with robust and consolidated genetics. This will allow for protected genetics in future reintroduction projects. The strategy involves crossing pairs from different locations in the breeding center and, simultaneously, providing these pairs to other institutions with different genetics to maximize reproductive variability.
Classified as one of the smallest Neotropical primates, the Serra Saki weighs about 400 grams in adulthood and has light fur. Like other members of the genus Callithrix, it lives in family groups that can range from three to twenty individuals.
Care Before and After Birth
The triplets were not the only ones born; veterinarian Fabiana Voorwald, an adjunct professor of veterinary surgery at UFV, is also part of the CCSS team. According to her, animal monitoring begins even before birth, with the monitoring of females during gestation. Fabiana describes that weekly weighings are performed at CCSS to track maternal weight gain, in addition to ultrasound and X-ray examinations at appropriate times during pregnancy, according to veterinary assessment. These exams help monitor the development of the pups and identify any alterations, guiding care for the mother and preparation for birth.
The team also adjusts the diet of the females to meet the nutritional needs of each stage of gestation. Supplements are personalized, seeking to prevent nutritional deficiencies that could affect maternal health and pup development, including those related to malformations. Care continues during lactation, ensuring breastfeeding and maintaining the mother's physical condition. The veterinarian adds that this situation offers a unique opportunity to gain deeper knowledge about a little-studied species, as scientific research and daily observations at CCSS provide data on behavior, feeding, health, gestation, parental care, and pup development.
Animal Recovery
Another crucial aspect of the work consists of recovering and improving the health conditions of wild sakis that will be integrated into the breeding stock. Some animals arrive at the center presenting with diseases or endoparasitoses that can endanger their lives, requiring specific treatments before being included in the groups. A significant problem is an infection caused by a worm that affects the intestinal tract of the Serra Saki.
Fabiana Voorwald reports that, in the case of individuals with *Prostenorchis* parasitism, the team developed and applied innovative therapeutic approaches due to the limitations of conventional treatments. The goal is to increase their chances of survival, promote recovery, and allow them to contribute to the safety population. Given the extreme threat to the species, the recovery of each individual is of great relevance to the program.
The veterinary team also actively participates in management decisions, engaging with professionals and students from various areas of UFV, such as biology, animal science, and forestry engineering. Researchers discuss group composition, social interactions, nutrition, enclosure conditions, and environmental enrichment, as the health and behavior of the animals are intrinsically linked. Stress can harm well-being, alter food consumption, and interfere with immune and reproductive response.
Fabiana Voorwald concludes that these results depend on the continuous effort of a multidisciplinary team and the articulation between actions under human custody and the protection of populations and their habitats in nature. CCSS also plays a vital role in training hundreds of students annually, allowing them to practically understand the challenges of conservation, the importance of every management decision, and the need to integrate different fields of knowledge.
The Serra Saki also benefits from public policies, such as the National Action Plan for the Conservation of Atlantic Forest Primates and Ring-tailed Monkeys and the Population Management Program. Both are coordinated by the Chico Mendes Institute for Biodiversity Conservation (ICMBio), in collaboration with institutions such as the Federal University of Viçosa.
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