Hedgehogs are small, noctural and camouflaged and therefore it is quite difficult to monitor them.
Where are hedgehogs? Monitoring distribution
There are two important sources of hedgehog sightings: RSPB’s Big Garden BirdWatch and the our very own BIG Hedgehog Map. All the data collected through the BIG Hedgehog Map is made publicly available through the National Biodiversity Network. Knowing where hedgehogs are is important when planning development, as it can stimulate mitigation, but this information doesn’t tell us much about the status of local populations. For this we need more detailed surveys.
How many hedgehogs are there? Monitoring population trends
Hedgehogs, like other mammals, have not been monitored as systematically as birds or butterflies in the past. As recently as 2010 PTES and BHPS commissioned the first formal review of data concerning hedgehog populations and produced the State of Britain’s Hedgehogs report in 2011. Another version of this was published in 2015 and we plan to re-run the analysis every two years. Two key surveys that feed into this are PTES’ Living with Mammals survey (urban) and PTES’ Mammals on Roads (rural) – you can participate in these surveys and help improve our understanding of how hedgehogs are faring. The general picture is alarming – with up to a third of all urban hedgehogs and at least half of all rural ones having been lost since 2001, and populations across the UK continuing to decline.