Hedgehogs are a native species whose decline has raised fears about their future among wildlife enthusiasts. A recent survey in Britain found that just over half of those questioned had never even seen a hedgehog, whose numbers there are estimated to have fallen from 30 million in the 1950s to 1 million today.
In Ireland hedgehog or gráinneoig numbers have also fallen. The reasons for their decline are not fully understood. Hedgehogs roam about a mile each night in search of food and mates. It is thought they have been affected by loss of habitat, increased road traffic as well as poisonings from slug pellets and rodenticides. In urban areas barriers to movement like concrete walls channel hedgehogs out onto dangerous roads. In addition, hedgehogs have natural predators in foxes, badgers and larger birds of prey like eagles.
Hedgehogs were once only found in deciduous forests but they have adapted to open field systems by living in hedgerows. They build multiple nests using grass, leaves and twigs which they frequent as they move through their domestic ranges. They avoid wetlands, mountain areas and coniferous forests. Individuals living in farmland tend to move further than their woodland cousins. Hedgehogs eat a wide variety of insects, slugs and snails as well as fruit and fungi.
They forage from dusk 'til dawn and hibernate from December until March. In order to survive the winter, they need to fatten themselves up and can eat up to 70g each night during autumn. They breed after their first hibernation and females can have two litters in a season, of 4-5 piglets or urchins per litter. Piglets are born blind and only grow their defensive spines a few days later. Females are very sensitive to disturbance and will abandon a nest if it is interfered with by humans.
There are many ways in which people can help hedgehogs. Gardening and farming activities often lead to accidental hedgehog deaths. They can have nests under old piles of brush so if these are to be burnt or moved, it is best to wait until spring and check beneath them before lighting the fire. Hedgehogs will rest under hedges during the day and so if you're out strimming long grass, check along under the hedge before cutting.
Hedgehogs are very susceptible to slug pellets in gardens as well as rat poison. The best thing would be to keep use of these chemicals to a minimum. If you want to encourage hedgehogs then it is possible to build attractive piles of wood and ensure access for these roaming foragers into and out of the garden.
If you discover a distressed hedgehog at this time of year then call the DSPCA for expert advice on 01 499 4700. It is best not to handle juveniles unless absolutely necessary as this will mean they are sure to be abandoned. Irish wildlife matters have an advice page here.