Research highlights dangers faced by hedgehogs before and after their winter hibernation

A study co-authored by a Keele University wildlife expert has shed new light on the dangers faced by UK hedgehogs in the run up to their annual hibernation period. 

Previous research has suggested that hedgehog populations across Europe have declined by 50% over the last 10 years in open countryside, and about 30% in urban areas – and there could be fewer than one million left in the UK. 

New research co-authored by Keele’s Professor Dawn Scott has uncovered fresh insights on the impact of hibernation and the environment on the survival orural hedgehog populations. 

The study, published in the journal Animals, has found that hedgehogs living in rural areas appear to be more at risk immediately before and after their winter hibernation period, rather than during the hibernation period itself. 

Hedgehogs face many challenges before and during their hibernation, which typically lasts between November and April. These include a need to accumulate sufficient fat reserves with limited food, finding suitable materials for building a nest, and finding an appropriate environment to build their nest with options for relocation if disturbed by humans, predators or inclement weather. 

The researchers found that a successful hibernation was influenced by several factors, all of which may be negatively impacted by agricultural intensification or climate change, and that hedgehogs consistently nested close to some habitats including hedgerows and woodlands, but avoided others such as pasture fields. 

The findings suggested that hibernation was not a period of significant mortality for hedgehogs that had reached a sufficient weight in autumn, but that habitat composition did affect where nests were built. Therefore, land management practices – both historic and current – that provide hedgehogs with access to vegetated areas are likely to positively influence hibernation success and the survival chances of hedgehogs. 

Professor Dawn Scott, Head of the School of Life Sciences at Keele University said: “It was previously thought that hibernation period was a high mortality period for hedgehogs. What we are discovering from our studies is that there are other risks to hedgehogs pre and post hibernation that we are starting understand to help support their population recovery.” 

The research was led by Lucy Bearman-Brown, Senior Lecturer at Hartpury University, and co-authored by Professor Scott alongside Dr Philip Baker and Dr Luke Evans from the University of Reading, and Dr Richard Yarnell and Dr Antonio Uzal from Nottingham Trent University. 

Mrs Bearman-Brown said: “Hedgehogs have declined markedly in the UK in recent decades and one key stage that could affect their population dynamics is the annual winter hibernation period. 

“Despite its potential importance and given the wide range of ways in which human activities could affect this phase, little research has been conducted on the hibernation behaviour of hedgehogs in Britain in the last 40 years. 

“Therefore, we radio-tracked 33 hedgehogs from two contrasting rural populations in England – at Hartpury and Nottingham Trent University’s campus near Southwell in Nottinghamshire – to examine patterns of winter nest use, body mass changes and survival during hibernation. 

“None of the hedgehogs that we monitored died during hibernation, which might be surprising. In fact, all deaths occurred prior to or after the hibernation period, mainly from predation or vehicle collisions.” 

The study was funded by the People’s Trust for Endangered Species (PTES) and the British Hedgehog Preservation Society. 

Nida Al-Fulaij, Grants Manager for PTES, added: “We can now focus our efforts on investigating what farm management practices, particularly of hedgerows and scrubby areas, can help give our rural hedgehogs the best chances of surviving hibernation. 

“Ensuring hedgehogs and other wildlife have access to plenty of secure foraging and nesting areas is going to be critical.”