The relationship between foraging complexity and foraging plasticity: Implications for the conservation of peach-fronted parakeets

Abstract

Reintroduction processes, whereby animals are reared in captivity and released into the wild, often fail. This failure is often attributed to the fact that released individuals not have the behavioral repertoire to cope with the wild. Compared to captive conditions, wild environments are highly complex, and therefore a released individual with greater behavioral complexity may survive better after release. Moreover, the wild presents both unpredictable features and regular changes, and thus plasticity of behavior may be crucial for survival. Considering the importance of foraging to fitness, foraging complexity and plasticity can be crucial to the success of reintroduction processes. We investigated captive individuals of Eupsittula aurea (Psittaciformes, Psittacidae) to evaluate if: a) food enrichment promotes foraging complexity; and b) there is a relationship between foraging complexity and plasticity. An animal that potentially has a good adjustment to wild environments would be one that has high foraging complexity and plasticity. We housed 40 parakeets under identical conditions that differed only in their diet. Twenty birds, in four replicated enclosures, were randomly allocated to the treatment diet which better replicated what would occur in the wild and consisted of multiple entire fruits, and food spatial randomization. The remaining 20 birds were placed into four control enclosures and received a diet that is currently provisioned for birds in captivity and consisted of small fruit cubes and sunflower seeds, offered on tray at a fixed location. Dietary enrichment does not affect bird foraging complexity. According to our expectations, foraging complexity influenced foraging plasticity for birds that were subject to the enriched environment. Therefore, more extensive foraging repertoires are related to a greater adjustment capacity in enriched environments, and complexity could be considered a good measure of adjustment to reintroduction success.