An account is given of the winter nests of the hedgehog (Erinaceus europaeus L.), and their importance in the life of this species.
Nests were constructed for protection during hibernation, in sites chosen for the degree of support gained from surrounding objects. They were usually made mainly of dry leaves, specially selected and carefully built into a robust weatherproof structure, by a method appropriate both to the hedgehog and the materials used. Construction of winter nests was closely correlated with environmental temperature.
The life history of hibernacula is reviewed and it is shown that nests may persist for well over a year, though the leaves of which they are made normally decay completely in a much shorter time. Nests built in brambles, with plenty of support last longer than those in less preferred sites.
The construction of winter nests was strictly seasonal, but their decay was gradual, with rapid deterioration at the end of the winter. About 30% of nests persisted till the following winter, though were not re-occupied.
Over half of the nests built were occupied for one month or less, though some were in continuous use for up to six months. New nests were built even in midwinter, but the likelihood of their being occupied immediately was affected by the weather. Hedgehogs rarely shared a nest, though empty nests were sometimes taken over by small mammals or Hymenoptera.
Most hedgehogs that died in their nests during winter were juveniles perhaps too inexperienced to construct an adequately protective nest.
The importance of the nest in a hedgehog's life, particularly during hibernation may be a significant feature in determining both its distribution and its habitat choice.