Restriction of anthropogenic foods alters a top predator's diet and intraspecific interactions

Abstract

Anthropogenic foods are utilized by many animals around the world, and these resources could impact dietary preferences and intra- and interspecific interactions. Under a quasi-Before-After-Control-Impact experimental design, we assessed how dingoes (Canis dingo) responded to a decline in anthropogenic foods in the Tanami Desert, central Australia. We did so by assessing dingo diets close to and away from human influence during a period when food waste was available at two rubbish tips, and then during a period when food waste was restricted at one of the tips. Our results demonstrate that access to anthropogenic foods can alter a top predator's diet. Namely, dingoes showed a preference for eating the desert mouse (Pseudomys desertor) in areas where food waste was restricted, whereas dingo diets did not reflect ambient prey availability at areas where food waste was constantly available. Reduced availability of food waste also affected interactions between dingoes, with cannibalism decreasing where food waste was removed, and it may have increased consumption of a subordinate mesopredator, the feral cat (Felis catus). By implication, efforts to manage food waste could reestablish or strengthen interactions between predators and their wild prey with possible cascading consequences for ecosystems.