Population density and community-based conservation of the Andean Titi Monkey (Callicebus oenanthe) in a secondary forest fragment in northern Peru

Background/Question/Methods

Lowland tropical forests regenerate rapidly following disturbance, and even fragments of secondary forests provide benefits such as wildlife habitat and community education.  The critically endangered Andean Titi Monkey (Callicebus oenanthe) is endemic to the Department of San Martin in Peru, where over 60% of its preferred habitat has been deforested and its population has been reduced by at least 80% in the last 30 years.  We conducted a call-based survey of C. oenanthe and estimated density via triangulation of calls in Pucunucho, a 23.5 hectare fragment of forest with 17 years of regeneration.  This study is part of a broader conservation effort aimed to educate and engage the local community. 

Results/Conclusions

We mapped 50 of 164 recorded C. oenanthe calls within Pucunucho in order to estimate the presence of at least 6 family groups in this fragment.  Our density estimates range from 105-130 individuals/km² depending on family group size.  This is substantially greater than other Callicebus density studies, though visual surveys of this morphologically cryptic genus may be prone to underestimation.  One previous call-based survey of C. oenanthe reported 141 individuals/km² and suggested that the method may be more precise but the study population may have also been in flux due to immigration from nearby deforested areas.  The abundance of C. oenanthe in a relatively young forest fragment suggests there is great potential for habitat restoration for this species.  As part of the broader conservation effort, we worked with local land owners to preserve a forested corridor connecting this fragment with the largest remaining continuous habitat for this species.