Crop Feeding by Brown Howlers (Alouatta guariba clamitans) in Forest Fragments: The Conservation Value of Cultivated Species

Abstract

Primates inhabiting human-modified habitats often complement their diets with cultivated species. Although this flexible foraging behavior reduces feeding stress in animals inhabiting small or low-quality habitats, its potential economic costs may promote negative human–nonhuman primate interactions. It is critical to assess the importance of cultivated species to primate diets, the factors influencing their exploitation, and their associated economic costs to evaluate the conservation value of cultivated species and the impact of crop feeding on human–nonhuman primate coexistence. Based on a 30-months study of three groups of brown howlers (Alouatta guariba clamitans) inhabiting <10-ha forest fragments in Rio Grande do Sul State, southern Brazil, and semistructured interviews with landowners, we assessed 1) the cultivated species used as food sources, 2) the relationship between food availability and crop feeding, and 3) the potential economic costs of crop feeding and their impact on landowner–howler coexistence. Brown howlers exploited six cultivated species as fruit or seed sources. This exploitation was concentrated on ripe fruit of Psidium guajava, Citrus reticulata, Diospyros kaki, and Eriobotrya japonica, which together accounted for up to 32% of total feeding records during some months. Availability predicted fruit consumption for three of these species. The overall availability of cultivated fruit also predicted its consumption, whereas overall wild fruit availability did not. Despite potential economic costs of crop feeding (US$320–US$1141 per year), landowners reported no conflict with howlers arising from their behavior, an amicable response that supports the conservation value of cultivated plants in different landscape elements of the anthropogenic matrix.