Anyone Can Get Old—All You Have to Do Is Live Long Enough: Understanding Mortality and Life Expectancy in European Hedgehogs (Erinaceus europaeus)

Abstract

The European hedgehog is in decline, triggering a need to monitor population dynamics to optimise conservation initiatives directed at this species. By counting periosteal growth lines, we determined the age of 388 dead European hedgehogs collected through citizen science in Denmark. The overall mean age was 1.8 years (1.6 years for females and 2.1 years for males), ranging between 0 and 16 years. We constructed life tables showing life expectancies at 2.1 years for females and 2.6 years for males. We discovered that male hedgehogs were more likely to have died in traffic than females, but traffic-related deaths peaked in July for both sexes. A sex difference was detected for non-traffic deaths, as most males died in July, and most females died in September. We created empirical survivorship curves and hazard curves showing that the risk of death for male hedgehogs remains approximately constant with age. In contrast, the risk of death for females increases with age. Most of the collected road-killed individuals died in rural habitats. The degree of inbreeding did not influence longevity. These new insights are important for preparing conservation strategies for the European hedgehog.

Hematology, Biochemistry, and Protein Electrophoresis Reference Intervals of Western European Hedgehog (Erinaceus europaeus) from a Rehabilitation Center in Northern Portugal

“…The species E. europaeus is on the International Union for the Conservation of Nature (IUCN) and Red Book of Vertebrates of Portugal (LVVP) red list, as being “least concern” because it is common and abundant throughout its wide range [ 5 , 6 ]. However, in the last decades, there are registers of a decrease in the number of individuals of this species [ 7 ] which can be justified by several factors: the Western European hedgehog has some natural predators that pose a threat to the survival of the species (badgers ( Meles meles ) are the most significant ones) [ 8 , 9 ]; as the hedgehog occupies agricultural areas, it is frequently exposed to poisoning by pesticides and rodenticides [ 10 ]; the transformation and fragmentation of its habitat, as well as climate changes, affect its survival [ 11 ]; they are one of the vertebrates that frequently suffer mortality owing to road traffic [ 7 ]; and finally, they harbor a wide variety of different parasites and pathogens [ 8 , 12 , 13 ].…”

First report of intestinal intussusception in Western European hedgehogs (Erinaceus europaeus)

“…In some European countries, the populations of hedgehogs are declining considerably, which should serve as a driver for understanding the biology of the species, its population dynamics and its health threats 4 . As hedgehogs are one of the mostly common animals in rescue centres, these facilities may provide important opportunities to increase knowledge of this species 2,3 .…”

“…The body condition at the beginning of hibernation, the time of the year and the development of the litter (pre‐weaned vs. post‐weaned) have a strong influence in the recovery and mortality of hedgehogs, especially the hoglets and young adults 3 . According to a recent study, 30% of E. europaeus ( n = 115/388) die before reaching 1 year of age, though some can live until 16 years old 4 . From a wildlife rehabilitation medicine perspective, this may indicate that an improvement in knowledge, management and treatment of the animals that reach the rescue centres may lead to an improvement in lifespan and population stability 4 …”

“…3 In some European countries, the populations of hedgehogs are declining considerably, which should serve as a driver for understanding the biology of the species, its population dynamics and its health threats. 4 As hedgehogs are one of the mostly common animals in rescue centres, these facilities may provide important opportunities to increase knowledge of this species. 2,3 Some of the most frequently reported reasons for admission in rescue centres include orphans, traumatic lesions due to car collisions and predation, poor nutrition secondary to hibernation disturbances or if births occur too late in the breeding season and parasites.…”

“…3 According to a recent study, 30% of E. europaeus (n = 115/388) die before reaching 1 year of age, though some can live until 16 years old. 4 From a wildlife rehabilitation medicine perspective, this may indicate that an improvement in knowledge, management and treatment of the animals that reach the rescue centres may lead to an improvement in lifespan and population stability. 4 Most gastrointestinal postmortem examination findings reported in hedgehogs have been associated with an infectious origin.…”