Between april 2005 and May 2006, according to the pressuposts of line transect methodology, census were carried to estimate abundance and population density of Callicebus nigrifrons Spix, 1823 (Pitheciidae) in Cantareira State Park, State of São Paulo, southeastern Brazil (23°23'42"S, 46°35'27"W). After 275.80 Km of census sampling effort, the titis were the second most abundant primate species, presenting an abundance index of 1.4 groups for each 10 km walked and a density estimate of 12.21 ind./km² (ranging between 8.45 a 17.63 ind./km²). The collection of ancillary data during the census allowed the determination of diet and habitat use by the titis groups, and results show a relative adaptability to disturbed habitats.
Atlantic forest; black-fronted titi monkey; conservation; density
