Data for: Nest material preferences in wild hazel dormice Muscardinus avellanarius: Testing predictions from optimal foraging theory

Obtaining nesting material presents an optimal foraging problem,
collection of materials incurs a cost in terms of risk of predation and
energy spent, and individuals must balance these costs with the benefits
of using that material in the nest. The hazel dormouse, Muscardinus
avellanarius is an endangered British mammal in which both sexes build
nests. However, whether material used in their construction follows the
predictions of optimal foraging theory is unknown. Here, we analyse the
use of nesting materials in forty two breeding nests from six locations in
Southwest England. Nests were characterised in terms of which plants were
used, the relative amount of each plant, and how far away the nearest
source was. We find that dormice exhibit a preference for plants closer to
the nest, but that the distance they are prepared to travel depends on the
plant species. Dormice travelled further to collect honeysuckle Lonicera
periclymenum, oak Quercus robur, and beech Fagus sylvatica than any other
plants. Distance did not affect the relative amount used, although the
proportion of honeysuckle in nests was highest, and more effort was
expended collecting honeysuckle, beech, bramble Rubus fruticosus and oak
compared to other plants. Our results suggest that not all aspects of
optimal foraging theory apply to nest material collection. However,
optimal foraging theory is a useful model to examine nest material
collection, providing testable predictions. As found previously
honeysuckle is important as a nesting material, and should be taken
account when assessing suitability of sites for dormice.