When I was young, we kept an old white-striped caravan hitched on concrete blocks in the garden next to a large, humid compost heap full of worms.
This set-up didn’t go unnoticed; one winter, we discovered a hibernating hedgehog underneath the caravan, nestled in piles of grass debris, autumnal leaves, and twigs. It likely used this same space during the spring and summer to rest during the day before venturing out on its nocturnal trips.
Upright and active, hedgehogs are surprisingly nimble. Walking home late one evening, as a teenager, I spotted one on the footpath. Its legs were remarkably long, and it raced forward with purpose, moving quickly as if eager to get somewhere.
It trotted along the concrete path until it turned left on to a large patch of grass, presumably in search of earthworms. A fox appeared from the shadows, but the hedgehog neither froze with alarm nor upped its pace. It merely snuffled its way around the grass and continued to look for food.
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It’s been years since I’ve seen one. It’s in forgotten, shabby and ignored spaces – hard to come by today – where hedgehogs are likely found. But, since they’re pretty adept at hiding away in prickly and stingy places (think mounds of nettles, brambles or hawthorn), I’m hopeful they’re still around.
The plight of hedgehogs is a cause for concern. We don’t know much about Ireland’s population, but data from other European countries point to a decline across rural and urban areas.
In the UK, numbers have fallen by 30 per cent in urban areas and 50 per cent in rural areas, and a few years ago, they were classified as ‘vulnerable to extinction’.
In Zurich, Switzerland, in what was the first study to quantify the decline of hedgehogs in a European city over time, their population plummeted by 41 per cent between 1992 and 2018. These figures underscore the urgent need for conservation efforts.
When conditions are right, hedgehogs can live up to 16 years. But last year in Denmark, researchers examined 388 dead hedgehogs and discovered that the average age was just 1.8 years. By counting the incremental rings in the bones of their jaws, they could accurately estimate their age. Males lived longer than females.
Understanding their decline is a guessing game, but it is likely due to various factors. The potential threats are many – habitat loss and fragmentation, concrete walls and electric fences, road traffic accidents, insect decline, diseases and parasites, accidents from garden machinery such as robotic lawnmowers, and rodenticide poisoning. But such is their nocturnal and secretive existence, there are few detailed studies over time which give a clear picture as to exactly why they are disappearing.
In rural areas, their immediate needs are simple: thick, flowering hedgerows and scrubland. The hedges are their homes and larders; without them, they’d die. Because of this, the smaller and more diverse the fields, the better.
Where hedgerows are fenced off from livestock, the mesh size must be large enough for hedgehogs to clamber through. Any reduction in chemical use on the land will help insects survive; organic farming methods can increase insect diversity.
We know that, in the recent past, hedgehogs moved into urban areas because of the pressures from the intensification of farming, fragmentation of habitat, and the expansion of their most formidable predator, the badger.
Urban areas can be ideal for wildlife – they have natural resources (most notably, food), fewer natural predators and can feature a mosaic of microhabitats. There’s plenty of evidence to show that hedgehogs have been found in higher densities in urban areas than in rural ones.
But densification in urban and suburban spaces is rapidly squeezing them out. More people living in cities – it’s estimated that by 2050, 66 per cent of the global population will do so, up from over half today – are reducing the amount of green space available. Fake plastic grass and a focus on tidiness in gardens and public spaces are all problematic, as is the use of chemicals such as herbicides, insecticides, and pesticides such as rat poison.
If you live in an urban area and can exert some influence in your home, school, sports club or with your local council, there are a few proactive things you can do, safe in the knowledge that what’s suitable for hedgehogs is also good for other species.
Think about leaving a space undisturbed – under a hedge or a shed is ideal – where they can rest and hibernate. Hedgehogs freely roam around urban areas – they can clock up a mile a night – but barriers between neighbours will stop them in their tracks. By making a small hole, just 13cm by 13cm, in fences and walls, you can help solve this problem.
Finally, consider sharing what you see. A few years ago, researchers from the University of Galway set up the All-Ireland Hedgehog Survey, and they’ve received thousands of records from all over Ireland, which they give to the National Biodiversity Data Centre (hedgehogs are some of the most commonly recorded species on their citizen science portal).
Whether you think you have hedgehogs in your garden, school or workplace, you can take part in their garden hedgehog survey, or if you live on farmland, there’s a questionnaire for rural dwellers who might like to help the researchers with their work.
See https://www.irishhedgehogsurvey.com for more.