Guigó

The Coimbra-Filho's Titi (Callicebus coimbrai), also known as Coimbra-Filho's Titi Monkey, is a small New World monkey in the family Pitheciidae, named in honour of the Brazilian primatologist Adelmar F. Coimbra-Filho. This titi monkey is endemic to the Atlantic Forest of northeastern Brazil, with its range restricted to the states of Sergipe and southern Alagoas—one of the most critically fragmented and threatened biomes on Earth. Adults are small, with reddish-brown fur on the flanks and upperparts, pale grey on the underparts, and an orange-red forehead band. Like all titi monkeys, Callicebus coimbrai is highly social, living in monogamous family groups of 2–5 individuals that engage in elaborate dawn duets and tail-twining behaviour as expressions of pair bonding. The species inhabits Atlantic Forest fragments, including lowland and highland forest patches, riverine gallery forest, and secondary growth, where it subsists on fruits, seeds, leaves, and occasional invertebrates. The Coimbra-Filho's Titi is classified as Endangered by the IUCN due to its severely fragmented range within one of the world's most deforested biomes, with less than 12% of original Atlantic Forest remaining, ongoing habitat loss from agricultural expansion, and small, isolated population sizes highly vulnerable to stochastic extinction events.