Manioc losses by terrestrial vertebrates in western Brazilian Amazonia

Tropical biodiversity benefits humanity. However, the costs of conserving topical biodiversity are largely borne by local communities. The damage caused by wild animals to human-cultivated plants (crop-raiding) in tropical ecosystems directly affects the livelihoods of local agriculturalists, which erodes their support for conserving biodiversity. We used data collected between 2013 and 2015 from 132 camera-trap stations and responses from 157 interviewees representing 47 semi-subsistence communities to quantify and contextualize terrestrial vertebrate crop-raiding damage to manioc (Manihot esculenta) agricultural fields (i.e., roçados) in the Médio-Juruá region of western Brazilian Amazonia. The 5 vertebrate species identified by respondents as the most damaging crop raiders were agoutis (Dasyprocta fuliginosa), collared peccaries (Pecari tajacu), pacas (Cuniculus paca), red brocket deer (Mazama americana), and spiny rats (family Echimyidae). These species were frequently detected by camera traps in early-successional forests. Respondents reported mean manioc stem losses to crop raiders of 7.3%/roçado. Proportional losses of more palatable manioc varieties were approximately 3 times higher than more phytochemically defended varieties, further constraining crop choice. Respondents estimated that in the absence of active crop-raider suppression, overall losses would have been 73.9%/respondent/annum, and therefore invested substantial effort in crop protection. Small communities, already economically disadvantaged by isolation from the material, service, and information monopoly of urban centers, were most affected by crop raiding. Although, the most damaging crop raiders are ideal candidates for sustainable subsistence hunting, we found only weak evidence of positive opportunities for agriculturalists to hunt crop raiders to compensate for crop losses. Our study indicated that crop raiding may continue to exacerbate the challenges inherent in tropical agriculture and represents a significant forest ecosystem disservice.