The role of personality in the foraging decisions of a mammalian generalist herbivore, the common brushtail possum.

Abstract

Predators and plant toxins which act as chemical defences, represent two different but proximate constraints for foraging herbivores, limiting food intake and influencing behaviour. Consequently, foraging herbivores respond to spatial and temporal variation in food resources and danger, making foraging decisions based on their nutrient requirements, while trying to avoid predators. Not all individuals within a population, however, will deal with this trade-off in the same way. One driver of this variation should be individual consistent behavioural differences, defined as ‘personality’. The immediate consequence of the existence of personality in a population is that different individuals will perceive their own personal landscape of food and fear. This, in turn, may alter how each decides to forage throughout the landscape. I have investigated aspects of predation risk, foraging strategies and individual consistency in behaviour of a model generalist herbivore, the common brushtail possum (Trichosurus vulpecula), to ultimately understand how personality influences foraging decisions of herbivores in the wild. I provided evidence of how personality affects decision-making by individuals in a natural context, showing that boldness influences foraging in response to food toxins and predation risk. I demonstrated that these two costs are perceived differently by individuals with different personalities. As a consequence, different individuals altered foraging behaviour in different ways resulting in different foraging outcomes between bold and shy animals. Foraging behaviour of possums at risky feeders in the field was related to the level of boldness they showed in captivity. This study provides an insight into the interactions between plants, predators and herbivores and the role of personality in influencing foraging behaviour.