DOI: 10.5061/dryad.rxwdbrvdc
title: Data for: Nest material preferences in wild hazel dormice Muscardinus avellanarius: Testing predictions from optimal foraging theory

description: 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.
description: Characterisation of Dormouse Nests Hazel
 dormice nests were obtained from six different sites (Site) throughout
 Southwest England (Figure 1) in collaboration with Devon Dormouse Group. A
 total of 42 summer nests (NestID) were used for data collection and
 analyses. Nests were located on five different species of tree, hazel,
 (<em>Corylus avellana</em> - 30 nests), oak (<em>Quercus
 robur</em> - 5 nests), birch (<em>Betula pendula</em> -
 3 nests), beech (<em>Fagus sylvatica</em> - 2 nests) and
 hawthorn (<em>Crataegus laevigata</em> - 2 nests). Nests were
 separated by hand, and plant materials (Material) were identified using a
 microscope when necessary (Figure 2 a and b). For the five nests from
 Pitt’s plantation that were analysed at the nest site, we used a twig to
 move around the nest material to identify the species. Plant materials
 were separated by species (both bark and leaf), and we recorded, a)
 whether a species was used or not (Use), and b) the percentage of each
 species in the nest (Perc). In all nests hazel bark, honeysuckle
 (<em>Lonicera periclymenum</em>) bark (not leaves), and
 ‘grass’ (most likely bluebell (<em>Hyacinthoides
 non-scripta</em>), were used as long strips to provide nest
 structure. The main plants used in lining the nest were oak, birch,
 bramble (<em>Rubus fruticosus</em>), beech, ivy
 (<em>Hedera helix</em>), hazel leaves, and hawthorn. Overall
 usage of moss was high, but out of 23 nests that contained moss, 13 of
 them had a mass of moss shaped as a cup, which indicates that most likely
 the dormouse nest was built on top of an old bird’s nest, so moss use was
 not analysed further. Other plant species sometimes used in the nests were
 rhododendron (<em>Rhododendron ponticum</em>), sycamore
 (<em>Acer pseudoplatanus</em>), blackthorn (<em>Prunus
 spinose</em>), fern (various species), elder (<em>Sambucus
 nigra</em>), and mountain ash (<em>Sorbus
 aucuparia</em>). Each of these was used in only one nest, except for
 blackthorn which was used in four, so these species were not included in
 the statistical analysis. We measured the distance (Distance) of the eight
 most common plant species (honeysuckle, hazel, beech, birch, bramble,
 hawthorn, ivy, oak) relative to each nest. The distance, measured with
 field measuring tape, was taken from the circumference of the tree in
 which the nest box was situated to the circumference of nearest tree of
 the above eight species, whether or not the species was used in that
 particular nest. 
description: In the file the columns describe the data, but for Effort there
 is only data for nests where the plant material was used.