An Update on the Taxonomy and Geographic Distribution of the Northwestern Titi Monkeys, Genus Plecturocebus (Callicebinae)

Vermeer J.; Tello-Alvarado J.; Luna-Amancio J.; Rylands A.B. · Primate Conservation (2025)

Resumen

Knowledge on the taxonomy and distribution of primates is essential for biological studies and the compilation of effective conservation strategies. To gather more information on the taxonomy and distribution of titi monkeys (genus Plecturocebus), we carried out primate inventories in different parts of Peru. Information from field observations was supplemented with an extensive literature study, the examination of museum specimens, and information extracted from internet sources to update distribution maps and to describe intraspecific phenotypic variation of eight different species of titi monkeys. Following a thorough analysis of available information and examination of museum specimens, we corrected the scientific name of the white-browed titi monkey from Plecturocebus discolor to P. leucometopus and we argue that P. caligatus should be considered a single species with several color morphs. Although titi monkeys of the genus Plecturocebus are generally considered parapatric, we show several cases of sympatry, probably resulting in hybrids. Intraspecific phenotypic variation is very high in some species, while others seem more stable in morphological characters. We discuss uncertainties in taxonomy and distributions and suggest additional research. With the updated distribution maps, figures, and photographs, we hope to assist scientists and naturalists to identify titi monkeys in the wild.