Interactions with humans reduce the success of foraging for anthropogenic food by capuchin monkeys (Sapajus libidinosus) in Brasília National Park, Brazil.

The progressive growth of urban environments has increasingly forced populations of nonhuman primates to coexist with humans in many cities, which has resulted in problems such as behavioral alterations, conflicts with humans, and threats to the health of the monkeys, due to their consumption of anthropogenic foodstuffs. These anthropogenic foods, which are rich in calories, are the principal driver of the proximity between humans and primates, even though the acquisition of these foods tends to be risky for the monkeys and involve a variety of challenges derived from specific features of the urban environment. The present study evaluated the success/risk relationship of foraging for anthropogenic food by tufted capuchins (Sapajus libidinosus) in Brasília National Park. The data were analyzed using a binary logistic regression, with the backward-stepwise Wald method, to investigate the factors related to the foraging success of the capuchins, considering variables such as their sex and age, the type of approach and its context, and interactions with humans. The capuchins were influenced by the anthropogenic context, which affected their foraging strategies and diet. Interactions with humans reduced the success of foraging for anthropogenic foods. Conflicts between humans and the capuchins were common, especially in the context of access to food. The capuchins thus preferred to access feeding resources directly, probably due to the reduced human interference, which resulted in greater foraging success for unattended food brought by park visitors and the raiding of trash cans. Based on the observed behavior patterns, a number of measures can be proposed to mitigate these conflicts. These recommendations include not bringing food into areas frequented by the capuchins, not reacting to approaching animals, and removing all trash generated during a visit. A cleaning team dedicated to the maintenance of the visitation area free of anthropogenic waste is also be recommended.

Indução do Uso de Ferramentas como Enriquecimento Ambiental para Macacos-prego (Sapajus libidinosus) Cativos / Induced Tool Use as Environmental Enrichment for Captive Capuchin Monkeys (Sapajus libidinosus)

RESUMO Testamos o efeito de um aparato que pudesse induzir o uso de ferramentas no comportamento de seis macacos-prego cativos. Utilizamos “animal focal” para o tempo gasto em estados comportamentais gerais e estados indicativos de estresse, concomitantemente com “todas as ocorrências” de eventos agonísticos e de comportamentos estereotipados. O grupo mostrou perfis de orçamento de atividades diversificados, com respostas variadas aos fatores estressantes a que estavam expostos. Alguns indivíduos reduziram alguns comportamentos indicativos de estresse, porém não houve variação significativa para o grupo. Conclui-se que o aparato não foi eficiente, mostrando suas limitações como medida de enriquecimento para a espécie. Em razão dos efeitos individuais, sugerimos, no entanto, que a técnica possa ser eficaz em grupos específicos ou condições muito estressantes.

ABSTRACT We tested the effect of an apparatus that could induce tool use on the behavior of six captive Capuchin Monkeys. We used “focal-animal” to estimate the time spent in general behavioral states and those indicative of stress, and “all occurrences” of agonistic and stereotypic behavioral events. The group showed different profiles of activity budget, with varied responses to stressing factors. Some individuals reduced the behaviors indicative of stress, but there was no significant variation for the group. We concluded that the apparatus was inefficient, limited as measure of enrichment for the species. However, due to individual effects, we suggest that the technique can be effective for specific individuals or groups under very stressful conditions.