In August, a friend took in a thin and needy young hedgehog (Erinaceus europaeus), which she'd found out in the day time and nursed it back to health. 'R', my friend, previously spent three years working for an animal rescue charity and knows how to care for hogs, so they're in good hands. Called Roo, this hoglet was cared for indoors initially, in a large wire crate, sleeping in the shelter of an adapted cardboard box on a heated mat and gaining weight at astonishing speed. After the initial weight gain, Roo was moved to an outdoor run, and this time his cardboard shelter was filled with bedding. Then at 650g, Roo made his own decision to leave and dug out one night, disappearing into the surrounding undergrowth.
Since then, my friend has been out at night finding and weighing local hedgehogs to see how many need extra food, which is then provided. All need to weigh at least 650g if they are to survive winter since starvation during hibernation is thought to be the most common cause of death.
Back at home, our own hedgehogs still visit every night though we've noted a sense of urgency in their eating now that the nights are cooling. Often they eat for half an hour at a time and then return later for more food. Listening to hedgehogs eat has become a new pleasure for me and I love to hear them chew and crunch with such obvious enthusiasm. That sound also means they are becoming plump, just as they ought to be to have a better chance of making it through winter.
Back to my friend R. A couple of weeks after Roo's departure, she found a tiny hedgehog wandering in the garden. Weighing just 180g, it was small enough to still need substitute milk. The following night, two more showed up, also very small, and then another two. They are being fed mashed kitten food mixed with a suitable formula milk, which looks disgusting. They all seem healthy and are gaining weight. R thinks they must be siblings and wonders if the mother of this late litter realised she would be unable raise them. In order to ensure her own survival she may have abandoned them. They'll live with R until spring when they'll be gradually be adjusted to living outside and foraging for themselves, before being set free to make their own way in the world.
If you find a very small hedgehog outside alone, especially during the day, it will probably need help. Contact the British Hedgehog Preservation Society for advice on 01584 890 801. There is also a useful information sheet here.