European hedgehog population declines

Efforts to monitor hedgehog populations through citizen science initiatives have highlighted significant declines across Northern Europe.

In Sweden, the World Wide Fund for Nature (WWF) launched an annual monitoring week to track the species, which is currently listed as ‘vulnerable’ following a population decrease of approximately 48% over twelve years. Research has identified distribution gaps in regions such as Bohuslän, Dalsland, and areas north of Stockholm. Experts attribute these trends to a lack of shelter and prey in rural areas, alongside potential factors like disease, toxins, and vehicle collisions. Recent data from the WWF and Nordens Ark Hedgehog Week recorded 50,774 sightings of living and dead hedgehogs. Organizers reported a significant increase in deaths caused by vehicles, and wildlife rehabilitators have seen high demand due to injuries from traffic, robot lawnmowers, and fly larvae. With population estimates suggesting the species has halved over the last 15 years, the hedgehog is set to become a protected species in Sweden starting this autumn.

In Denmark, annual counts confirmed a notable drop in numbers, with 16,884 hedgehogs recorded compared to 21,374 the previous year. Researchers from the Natural History Museum of Denmark and Oxford University suggest that record-breaking heat and dry summer conditions may be driving mortality due to a lack of food and water. Researcher Sophie Lund Rasmussen noted that many citizens reported hedgehogs disappearing from gardens between June and July. Data indicates the proportion of participants failing to spot a hedgehog rose from 10.8% to 16.7%, with the highest rate of unsuccessful sightings in the Capital Region at 22.3%.