I pride myself on being able to answer all questions I am asked when doing talks - there was one instance when a highly irritating child asked me at a festival in Norfolk whether hedgehogs could see in colour, which is a good and sensible question and one that I did not know the answer. 

Afterwards I talked to her and her dad and got his email address so I could send the answer - and the answer is - a bit. They have some colour sensitivity. 

Oh, and then there was the irritating child who asked me how many hedgehogs (not species of hedgehog) there were in the world … I made up a number!

But on Saturday I was in Stockport, giving a talk for the Cheshire Wildlife Trust at the wonderful Kindling Trust - when this question was asked - how big is a hedgehog’s heart?

It turns out the stimulus for this was not just to flummox me, but it came from a reference to the heart of a whale - probably the blue whale, who possesses the largest heart on the planet, into which you could, if so moved, drive a golf buggy.

But what is the answer? My bible is the monograph by Nigel Reeve - unfortunately out of print, but still will turn up in second hand bookshops, so keep an eye out!

Nigel did not provide the answer, so I turned to the internet. If you google ‘hedgehog heart’ you mostly get cute and whimsical images, but there are the occasional anatomical photograph, which lead me to a paper which tells me that for Atelerix albiventris, an African hedgehog, much smaller than our own, the heart weighs in at just 1g - 0.42% of its bodyweight. It is not unreasonable to assume that the heart in a larger species will be at roughly the same proportion to the rest of the body, so - to the person who asked the awkward question - Stacey, I am looking at you - a 1kg hog, getting ready for hibernation, probably has a heart that weighs in at around 4g!

And what an amazing heart it is. During normal activity it will beat at up to 280bpm. When asleep it slows to around 150bpm. But in hibernation, this can drop to 5bpm.

There has been talk of trying to develop hibernation in humans for decades, and it popped up in the press last week … there are times when the winter is at its greyest that the thought of just shutting it all out is rather appealing. But then the sun comes out on a jewelled spiderwebs and suddenly I would not want to miss it at all!

To be successful, hibernation requires a good hibernaculum. And if you were to want to build the perfect hibernaculum, all you need to do is collect together a big heap of dried leaves, the surround those leaves with a structure of small twigs, and around the twigs, places some bigger pieces of wood, and then, around that, some more substantial chunks of wood. For a hedgehog you have made a wonderful home. But you have also built a bonfire.

So PLEASE - as we come to this time of year - PLEASE only build your bonfire on the day you are going to light it, thereby stopping hogs (and other lovely creatures) taking up home. More advice here at the BHPS. 

And while we are on the subject, could we just pause for a moment to think about the impact of fireworks on wildlife. Getting an elderly rescue dog made me see for the first time the misery that fireworks cause. He is terrified. But then I was shown this clip on twitter from Martin Bracken of a hedgehog reacting to fireworks and it made me think about how much of an impact our activities must be having. PLEASE don’t just go setting off your own mini display - or if you have one, find fireworks that don’t make a noise. And if you need the thrill, go to an organised display, and we will put the radio and TV on loud, and cover poor Ogli in blankets on the sofa and sit with him as he trembles.

However big a hedgehog's heart may be, it does not need this extra stress.

Events that are coming up - I am talking to the Kent Mammal Group on Saturday, and then on 27th October I will be talking in a venue to which I never imagined I would be invited … Lambeth Palace!  If that was not enough, it is being chaired by the amazing Tom Shakespeare!

As ever, if you have any spare change (which I know is increasingly unlikely) my hat is open for donations … 

Thank you to Simon’s Cat for the entertainment.

p.s. Just to clarify, as it seems that not everyone gets my sense of humour - I LOVE irritating questions from inquisitive children - that is why I keep going back for more ...