Ecological and Behavioural Flexibility of Mantled Howlers (Alouatta palliata) in Response to Anthropogenic Habitat Disturbance

While howlers are the most ecologically flexible of the atelines,they must still respond to issues arising from anthropogenicmodifications, such as fragmentation or dietary changes. A group ofAlouatta palliataliving in a highly modified landscape (commensal group) at the CuruWildlife Refuge in Costa Rica was compared to howlers with limitedhuman influence (control group). The commensal group had a morefrugivorous diet than the control group (H= 9.23,p= 0.002) due to crop-foraging of mango fruits. The commensal groupmaintained a larger home range than the control group, at 39 and 10ha, respectively. The commensal group also had increased travel (H= 7.37,p= 0.007) and feeding (H = 7.34,p= 0.007) time, as well as reduced proximity to conspecifics (H= 44.77,p= 0.000). There were no significant differences in rates of eitheraggressive or affiliative social behaviours. The increased homerange, shift in diet, increased travel and foraging time andreduced group cohesion demonstrated by these animals representresponses to the varied utility of available landscapes and themore widely dispersed resources in their range. These datacontribute to our understanding ofAlouatta, one of the most successful of Neotropical primates in modifiedlandscapes.