What moves from the south of England to the north of Scotland at walking pace, and goes slower up hill? (answer at the end of this blog)
Forty years ago my mentor, Pat Morris, did a fascinating survey looking at the different times hedgehogs emerged from hibernation across the country. He showed what one would expect, that hedgehogs emerge from hibernation earlier in the warmer south west of England and later in the north of Scotland.
As you can see from this graph of his work, the evidence is clear. And like the good scientist he is, he has kept this idea bubbling away … because often scientists will find that data collected for one purpose can later be used to investigate another.
His survey measured the geographical impact on hibernation. But it allows us now to look at the temporal impact too – how emergence from hibernation has changed over time.
Why should we be interested in this?
Because the biggest environmental story of the moment could be revealed in the data – the impact that a warming climate has had on us so far might be hardly noticeable, we are so insulated from the outside world that we hardly notice the passing of the seasons! But for wildlife out in the wilds – well subtle changes in climate can manifest subtle changes in behaviour. And one measure is WHEN the hedgehogs emerge from hibernation – which we can measure most effectively not with specialists in lab coats or satellites – but with YOU – citizen science.
The survey is simple – all you need to know is HERE on the Hedgehog Street website. You can take part in a study of phenology! (phenology is the study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate (taken from Wikipedia … which is down today in protest at web restricting legislation))
This is not the first use of citizen science to study the changes in the seasons, for example the Woodland Trust and the Centre for Ecology and Hydrology also run Nature’s Calendar – but the hedgehog hibernation survey is going to be a wonderful addition to our knowledge of the changes afoot.
And why should we worry?
Well, before we can worry we really need to see what is happening … so PLEASE do the survey. However, there are concerns about how changes in the climate might affect the lot of the hedgehog. More extreme weather events, for example, could be bad. Warmer winters might NOT benefit hedgehogs either. Being disturbed by unexpected mildness during the winter can deplete important fat reserves within the hedgehog, reducing its chances of survival when it re-enters hibernation.
There is a chance that if there are shorter, milder winters, hedgehogs might also benefit from being able to feed longer before entering hibernation – putting on more weight and increasing their chances of survival. This would be particularly valuable for late born young (possibly second litters).
And if climate changes are so severe that in the end hedgehogs give up hibernation, should we worry?
Perhaps surprisingly, no. Hedgehogs do not NEED to hibernate – and when our European hedgehogs were exported to New Zealand in 1855 (a long story – read my book for more details!) the ones that made their home in the warmer north island hardly hibernate at all.
But to repeat – for now what we need is data – data which we can use to compare now with Pat’s first study 40 years ago. It will be fascinating to see what changes there have been – so please join up and fill in the survey.
And the answer to the question at the top? … Spring!