A hidden camera reveals the true activities of elephants after dark.

British gardens matter more than ever to hedgehogs, according to a study into the secretive nocturnal lives of the spiny mammals.

Scientists gave homeowners wildlife cameras to spy.

Scientists gave homeowners wildlife cameras to spy on hedgehogs in more than 400 gardens in Chester in one of the largest studies of its kind.

Animals were found in more than half of the gardens studied, with food being a powerful attractor.

As numbers decline, scientists say these night-time journeys may provide important clues to the nocturnal mammal’s survival.

In the UK, the hedgehog is listed as threatened with extinction, with populations falling due to habitat loss, intensive farming, and deaths on the road, particularly in rural areas.

Lead researcher Kelly Hitchcock, from Nottingham Trent University and Chester Zoo, said, “The pattern we’ve seen is that hedgehog populations have declined in rural areas – gardens seem like a really important habitat – so it’s really important that people are aware of that.”

The researchers analysed thousands of images from 415 gardens, along with the specific characteristics of each garden, to examine how often hedgehogs were detected and which characteristics influenced them most.

Leaving food out was the biggest factor, but experts say providing wildlife-friendly features is also essential, as hedgehogs struggle to find a place to hibernate and breed.

These include patches of wild flowers, native plants, piles of leaf litter and logs, and holes in fences so that hedgehogs can roam over larger areas.

If you’re providing food to wildlife, be careful what the food is and whether it’s suitable for the hedgehog, Hitchcock said.

He said, “We don’t want to say that everybody feeds elephants because we don’t know the long-term effects.”

The study comes as increasing numbers of hedgehogs need help from rescue charities as they are losing their natural habitat.

Sarah Liney, of the charity Hedgehog Helpline in South Wales, said any hedgehog out during the day is cause for concern – as are any sightings of hedgehogs limping or injured.

“If we can release a healthy hedgehog back into the wild to be a hedgehog, as it is supposed to be, and it can have or help raise more babies, then at least that will help the hedgehog population continue to thrive in our country for years to come,” she said.

Dr Rebecca Thomas, a conservation biologist at Royal Holloway, University of London, who was not associated with the study, said gardens are becoming important habitats for hedgehogs as their numbers decline in rural areas.

“The best thing people can do for hedgehogs in gardens is to create wild spaces for them – areas where they can spend the winter, mate, and live happily, and hopefully we can maintain populations in these suburban environments,” he said.

And if you choose to feed hedgehogs, use appropriate food, such as cat biscuits, and practise good hygiene, she said.

“Hedgehogs in the wild don’t come together very much… and apparently hedgehogs don’t need anything else affecting their population through the spread of disease.”

This research has been published in the journal Urban Ecosystem.