An ageing caravan with a white stripe, placed on cement blocks, was parked in our garden during my childhood. It sat right next to our sizeable worm-filled compost pile that was always slightly damp. This set up did not remain unobserved for long; during one winter season, we uncovered a hedgehog hibernating below the caravan, snuggled amidst mounds of grass waste, autumn leaves, and twigs. Presumably, the creature utilised this zone for its daytime resting periods in the warmer months, before it traipsed into the night for its nocturnal adventures.
Often overlooked, hedgehogs are rather agile when upright and in motion. Reminiscing my teenage years, I recall encountering one during a late-night walk home. The creature’s legs were astonishingly elongated and it moved with a swift determination, implying a sense of journey. It treaded the cement path up to a point where it veered onto a generous patch of grass; probably a part of its hunt for earthworms. The emergence of a fox didn’t deter or threaten it, it simply carried on snuffling around for its meal.
Sadly, it’s been a long while since I last saw a hedgehog. They are frequently found in overlooked and shabby spaces – that are increasingly rare today. While they possess the skill of concealing themselves in thorny areas such as heaps of nettles or hawthorn bushes, there’s still hope that they continue to thrive.
However, the deteriorating situation of hedgehogs raises some serious concerns. It’s a fact we’re uncertain about the hedgehog population in Ireland, although figures from other European regions suggest a worrying decrease across countryside and cities.
The UK has seen a sharp drop of hedgehog numbers by 30% in urban regions and 50% in rural locations, leading to their classification as ‘veritable to extinction’ a few years back. In Switzerland’s Zurich, a study – the first of its kind to measure the plunge in hedgehog count in a European city – revealed a 41% decrease in the population from 1992 to 2018. These alarming statistics highlight the urgent necessity for swift and significant conservation initiatives.
Hedgehogs, under optimal circumstances, can survive till the ripe age of sixteen. A study conducted in Denmark on 388 deceased hedgehogs revealed an average lifespan of just 1.8 years, as determined by examining the growth rings in their jaw bones. The research indicated longer life spans in males than females.
The root cause of their population’s decline remains uncertain with multiple contributing factors. Their existence is predominantly nocturnal and secretive, making it challenging to identify precisely what drives their numbers down. Loss of habitat, accidents, diseases, parasites, exposure to rodenticides, and changes in the ecosystem, notably insect scarcity, are some conjectured reasons.
In the countryside, their primary necessities are simple: flourishing thick hedgerows and scrublands, which provide shelter and nutriment for this species. Hence, farms with a variety of small fields are the most beneficial. If hedges are separated from the livestock by fences, it’s crucial to ensure a mesh size that allows a hedgehog to climb through. Reducing chemical usage on the land and adopting organic farming procedures can enhance insect diversity, helping these creatures prosper.
Historical evidence suggests that hedgehogs migrated to urban territories due to the intensification of agriculture, habitat fragmentation, and increased badger presence, their primary predator. Urban territories can provide a haven for these gentle creatures due to present natural resources, fewer predators, and diverse microhabitats. Some evidence suggests higher hedgehog population density in urban regions compared to rural ones.
However, rapid urbanisation and suburban densification are making these spaces increasingly less hospitable for hedgehogs. The global urban population is anticipated to rise to 66% by 2050; this shift is shrinking the amount of available green space. Not just that, artificial turf and the tendency towards cleanliness in public places and gardens decrease their survivability, while the usage of agricultural chemicals such as pesticides, herbicides, and rat poison also poses threats.
For those residing in city areas, there are a range of proactive actions you can take that not only benefit hedgehogs, but other species too, provided you have certain influence at your home, school, sports venue or local council. Consider designating a quiet area – under a shed or hedge is ideal – where they can sleep and hibernate. Hedgehogs are known to wander about urban territories, covering up to a mile per night. However, obstructions between neighbouring properties hinder their movement. You can tackle this issue by creating a small aperture, roughly 13cm by 13cm, in walls and fences.
Furthermore, sharing your observations would be a good idea. A few years back, the University of Galway initiated the All-Ireland Hedgehog Survey and accumulated thousands of recordings from every corner of Ireland, which were then submitted to the National Biodiversity Data Centre (hedgehogs are among the most frequently recorded species on their public science portal).
Regardless of whether you suspect the presence of hedgehogs in your garden, school or workplace, you are welcome to contribute data through their garden hedgehog survey. Additionally, if you’re a resident of farmland, you can engage in a questionnaire designed for rural inhabitants who are keen on supporting the research. More information can be found at https://www.irishhedgehogsurvey.com.