Linking movement of individuals with population-level responses to habitat loss and fragmentation

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Habitat removal turns large, contiguous habitats into smaller, fragmented ones. For many species small habitats are less suitable than large ones, and the risk of local extinction is increased as habitat is removed. Some species exhibit a phenomenon of lowered fitness with smaller population size (also called an Allee effect), and are especially at risk from habitat removal since less habitat will result in smaller populations with lower fitness. For example, southern flying squirrels (Glaucomys volans) nest as a group during winter in order to reduce the amount of surface area that each squirrel exposes to ambient temperatures. If winter survival of squirrels is positively related to nest group size, then these squirrels will have higher winter mortality in smaller groups, and be at risk of local extinctions in small habitats. This research program involves testing for the relationships between animal behaviour, habitat removal, and extinction risk. We will be using a nest box experiment to manipulate the size of flying squirrel nest groups during winter, to test whether group size is related to survival. We will also undertake field surveys of flying squirrels in habitats of different sizes to test the predictions that: there is a threshold minimum habitat area, such that flying squirrels can not occupy smaller habitats because of an Allee effect; and the minimum habitat area threshold varies with the severity of winter temperatures (for example, with latitude).