We conducted field surveys for titi monkeys (Callicebus spp.) in the vicinity of the original collection sites of two poorly known species, Callicebus olallae and Callicebus modestus. Two distinct Callicebus forms were photographed and filmed, and according to an examination of existing literature as well as the original specimens, these represent C. olallae and C. modestus. They occur in patchy and fragmented grassy woodlands and appear to be at least locally threatened by hunting. Both were known from single locality collections and the taxonomic distinctiveness of these forms urgently needs to be further investigated, as does their true conservation status.
Bolivia
Callicebus
taxonomy
titi monkey
