Richard Collins: Citizen science survey on hedgehogs
Ujvari/mti Is Science And Falling Via Ap Survey To Trying Citizen Across Hedgehog Causes Scale The A Europe The Sandor Calculate Of Picture: Numbers Examine Problem Are
— Ralph Waldo Emerson.
A Danish hedgehog was 16 years old when it died. Another reached 13. Prior to these, the maximum hog lifespan recorded in Europe was nine years. The new records were made during a citizen science survey led by Sophie Lund Rasmussen known, according to ScienceDaily, as ‘Dr Hedgehog’.
The spiky eaters of slugs and snails are in trouble — their numbers are falling everywhere in Europe. Rasmussen’s project was an attempt to measure the rate of the decline and discover its causes. Beginning in 2016, Danish wildlife enthusiasts were asked to collect hedgehog carcasses and submit them for analysis. More than 400 contributors supplied 697 bodies.
I have written this article for The Conversation about my research on dead hedgehogs and how we can use the knowledge to help save the hedgehogs🦔https://t.co/h3672gj4yk@WildCRU_Ox @OxfordBiology @hedgehogsociety @UniofOxford @aauengineering @mplsoxford @Carlsbergfondet @PTES
— Dr Hedgehog 🦔 Hedgehog Research (@Dr_Pindsvin) February 27, 2023
Broad-leaved trees hibernate, producing annual growth rings. The age of a tree can be determined by counting the rings in a cross-section of the bark. Hedgehogs also hibernate: bone development ceases, resulting in growth lines in the jawbones. By examining these, age at death can be determined. Around 30% of Danish hedgehogs, analysis showed, don’t get to celebrate their first birthday and less than half reach their second.
‘The older they get, the older they get’, as the saying goes about longevity in wild creatures. The first year of life is the most challenging for almost everything. To survive it, a youngster must have received the ‘right’ genes in the lottery of life. Then experience kicks in. During that first year, valuable lessons are learned about the trials of life; where to find food, avoid danger and who’s who in the pecking order. With each year that passes, the prospects of further survival improve. The rule applied to humans until comparatively recently: infant mortality was huge just a few centuries ago.
Female mammals, including humans, generally live longer than males, but the Danish hedgehogs buck the trend: ‘boars’ lived 2.4 years compared to ‘sows’ at 1.6. This is an intriguing finding. Males have larger home-ranges than females. They roam more widely, particularly during the mating season when searching for partners. A study published in 2010 found that males cross roads more frequently than females. Wandering increases the risk of being killed on roads. Sows need extra food during lactation at this time. They search more extensively for food, rendering them particularly vulnerable on roads at this time. However, this scarcely explains the considerable difference in life expectancy between the sexes.