With the exception of the occasional cold-snap it is fair to say that we don’t really experience a true winter in Norfolk any longer, although it may not feel like it when a north-east wind drives in off the North Sea. But what are the consequences of our increasingly tame winters? 

One would think that our wildlife thrives in much milder winter weather, and it is true to say that some do. Non-migratory birds can struggle in cold weather and species such as Cetti’s warbler, Dartford warbler and bearded tit have had their populations decimated by a harsh freeze, particularly if the spell is delivered late in the season.

Common Shrew, credit Alan Price

Increasing average temperatures have pushed autumn deep into December and spring is ready to burst forth as February comes to a close, although many gardeners and early nesting blackbirds (keen to miss the rush) are often caught out in late March by a brief ‘Arctic blast’. 

Overwhelmingly our native wildlife has evolved to endure months of cold and snowy weather. Some species, such as shrews and voles, have a higher winter survival rate on mainland Europe than in our own warmer maritime climate, presumably living among vegetation under a layer of snow is more comfortable and forms a cover from predators. Hibernating hazel dormice, hedgehogs and bats do better in the colder winters, as warm spells can rouse them from slumber and forces them to burn up precious fat reserves. 

The grey seal, a relic of the ice age, seems a little out of place on the coast of Norfolk. The pups are born in winter on our sandy beaches in a covering of white fur, camouflage better suited to a backdrop of ice-floes and snowfields. The white camouflage of mountain hare and ptarmigan is advantageous on the high tops of the Cairngorms, but on the lower slopes its purpose has been lost and can prove a serious liability, East Anglian stoats dressed in ermine fur are almost unheard of now, and even in Scotland they are seldom seen.  

Yellow rattle, credit Elizabeth Dack

The consequences of our increasingly tame winters is not just an issue for animals, many of our native plants prosper from a good hard winter too. Yellow-rattle, often referred to as the meadow maker, is semi-parasitic and prevents grass growth becoming too vigorous, thus providing space for other flowering plants. The yellow-rattle seed will only germinate if it experiences a freeze and as an ‘annual’ it can disappear completely from an area without its touch of ground frost. Dormancy for many native flower’s seeds is broken not by a rise in temperature but a drop. The season’s cycle of frosts, freezing then thawing, softens a seeds tough shell enabling it to take up water and burst open its seam. 

The climate of the British Isles has fluctuated over tens of thousands of years and most of our native wildlife has evolved to deal with its peculiarities, however, the rate at which climate change is occurring and the rapid increase in average temperatures will challenge our natural world. Norfolk Wildlife Trust believes it is essential to mitigate by ensuring that our environment can sustain substantial and strong populations in a variety of protected and connected habitats. This, it is hoped, will keep our native species robust enough to meet any future climate challenges. 
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