As I write this I can be quite confident that in badger setts across the country, female badgers are either giving birth or getting very close to doing so.  Up to mid-February is the peak time for badger births.

The reason I can be so confident is that badgers have amazing control over their reproduction via a process called delayed implantation.  The badgers can mate at any time of year (spring and late summer seem to be particularly favoured times) and yet give birth in February.

What happens is that the egg gets fertilised in the normal way.  Egg and sperm combine and the cells start to divide.   But the fertilised egg does not implant itself into the uterus and continue to develop as would be the case in most mammals.  Instead, the small ball of cells, called a blastocyst, stops developing and goes dormant, drawing just the small amount of oxygen and nutrition it needs to survive.  In late December the blastocyst attaches itself to the wall of the uterus and starts to develop into a full foetus, to be born in February.  This is delayed implantation.  It means that the badger mating I witnessed in August (see Fieldnotes: 8th August 2009 – Sex) could result in cubs being born now.

Delayed implantation is not unique to badgers.  It occurs in a number of other mammals such as stoats, bears, Roe Deer and Grey Seals.  The evolutionary advantages of the process are clear – it means that the young are always born at the optimal time to take advantage of the best food resources in spring.

For badgers, there a few interesting implications.  Ernest Neal speculates that delayed implantation allows the badgers to mate throughout the year, which may help to strengthen clan relationships.  Hans Kruuk makes the point that multiple matings with different males could result in multiple blastocysts, meaning that each cub in a litter could have a different father.  Badger families must get complicated sometimes!  This is even more interesting when you remember that the dominant female badger may kill the cubs of other females to maintain her position.  This control over the genetic make-up of the clan is very much a female thing.  It must be related to the fact that you can never be sure who the father is, but there’s never any doubt about the mother.

Now, I’ve been thinking about badgers, and about delayed implantation, and I’ve got my own little theory.  This is just my own idea, so if it’s wrong then I take full blame.  My line of thinking goes like this: most of the mammals that practice delayed implantation are solitary by nature.  This means that the males and females come into contact only irregularly.

Delayed implantation offers an evolutionary advantage to these species because it means that a male and female can meet up at any time of year, mate, and still have the offspring born at the best time.  It is a way of compensating for geographical and territorial dispersion.

But badgers are different.  Badgers live in social groups where males and females come into contact every day.  For clan-living badgers, delayed implantation offers no great advantages.  Why don’t female badgers simply come into season in December and have cubs via direct implantation?  Neal’s theory about the regular mating strengthening group bonds is one plausible explanation, and there may be a further advantage gained by the genetic diversity of litters sired by different fathers, but I think it tells us something about the evolution of badgers.

I think that delayed implantation is an evolutionary throwback to a time when the Eurasian Badger was a solitary animal.  I think it points to a period in the history of the badger when they didn’t live in social groups and therefore gained an advantage from it much as stoats and seals do today.  In turn, it suggests that clan living is a relatively recent development for badgers.

It isn’t as wild a theory as it sounds.  Other badgers around the world are still solitary – the American Badger, the Honey Badger, the Indonesian Stink Badger, and so on.  Even our own Eurasian Badger is solitary across large parts of its range.  In Mediterranean regions, where food is scarce, badgers are virtually solitary.  Rather than this being an adaptation to the dry conditions, it’s my belief that delayed implantation shows that this is their natural state, with clan living a relatively recent adaptation to the conditions of North West Europe.

Despite the freezing temperatures and the occasional snow flurries this weekend, there are signs that the winter won’t last forever and that spring is round the corner.

The first snowdrops have appeared at the edges of the woods and are peeping out from the frosty ground.   The first of the spring flowers, they are taking full advantage of the light that’s available on the woodland floor before the foliage of the trees and shrubs develops later in the year and puts them in shade.

We’ve also had the first eggs from the chickens this week (Monday, to be precise).  Chicken egg-laying is determined by light, not temperature, so the days are obviously getting long enough to stimulate them out of their winter break.

To celebrate, here is a wholly gratuitous picture of a chicken.  Meet Clarissa, everyone.

The weekend before last I went out into the snow, and amongst the tracks were a set that puzzled me.  The gait was very like a rabbit or a squirrel – a bounding gait with all four paws together in a group.  The size as very small though – bigger than a mouse (and a mouse wouldn’t bound) and yet much smaller than a rabbit or even a squirrel.

I have been consulting the guidebooks and I think I have a suspect.  Bang and Dahlstrom’s Animal Tracks and Signs has this to say about stoat tracks “Walking prints are very rare, as they move exclusively by jumping.  On reasonably hard ground, such as solid snow, the tracks in jump groups may be four and four, often similar to a small hare.“   The Hamlyn Guide to Animal Tracks, Trails and Signs, adds that the stride length for a bounding stoat is typically 30cm.  Weasel tracks are smaller with a stride of 25-30cm.

Tentative stoat tracks in snow

The stride length of my tracks is about 20cm, so a little short, but otherwise the size and gait fits a stoat or weasel.  I can’t find anything else that fits the tracks, so at the moment I’m settling for stoat or weasel as a tentative i.d.

This is exciting stuff.  I have a thing about stoats (and weasels).  I’ve only ever seen these secretive little mustelids a few times, and any evidence that they’re at large in the area is good news for me.

I must be the only person in Britain at the moment wishing for more snow so that I can go and look for more tracks…

The snow has finally melted.  Today has been a balmy 7 degrees and beautifully sunny.  It may not sound very warm, but compared to the past weeks when the temperature didn’t rise above freezing for days on end it feels positively spring-like.  I took advantage and headed out for a stroll in the (slightly soggy) countryside.

I had no particular aim in mind, but with a vague idea of looking at the birds I headed over to the lake.  I don’t go there very often, but there is always the chance of visiting waterfowl.  As it happened the lake was still iced over with not a bird in sight, but the hedges were alive with blue tits, great tits, chaffinches and sparrows.   My personal favourites were a flock of long-tailed tits working their way through the trees.  These are delightful birds but absolutely impossible to photograph.  They are always on the move, flitting about from branch to branch as they forage, never staying in one place for long.  One of these days I’ll be in the right place and get a picture as they travel past.

Talking of ambitions, there is one animal that I’ve been quietly trying to photograph for a while now, and that is the black squirrel.  The black squirrel is the melanistic (black) version of the common grey squirrel.  There are populations of black squirrels in a number of places around the country, and some experts believe that the black coat is genetically dominant and will eventually replace the ordinary grey colour.  This hasn’t happened yet, or shown any signs of doing so, so black squirrels are still fairly uncommon.

There is a known population of black squirrels centred on Woburn in Bedfordshire.  I’ve only seen one once before, and it was very striking – a squirrel, but with a black coat.  Ever since then I’ve wanted to get a picture of one.  Today, I got my chance.

The almost legendary Black Squirrel of Woburn

Unfortunately the squirrel was quite distant so it was at the very limit of my camera zoom, but it is unmistakeably a black squirrel. I feel a little bit like those people who photograph Bigfoot, only to get home and find the picture only shows a dark blur in the distance, but at least I know it was there.

NOT a Bigfoot, but a black squirrel...

I walked home along the brook.  Halfway down I came across a clear animal path running from an old, disused little quarry into the fields.  Now, this looked to me like a classic badger path.  The old quarry was a perfect spot for a badger sett – they love places like this where they can dig sideways into the side of a bank, and the soil is usually dry and well-drained.  There were signs of digging and spoil heaps in the quarry, so something was burrowing there.  In short, it looked exactly like a badger path, except it ran across a 6″ deep fast-flowing brook.

The brook crossed by a badger(?) path

Could this really be a badger path?  Would the badgers really wade across the brook every night to get to the fields?  There were no really conclusive tracks so it is difficult to be sure either way.  Something had made the path, but I don’t know what.  Since the brook is close to my house it looks like an ideal place to make a track trap – to spread some sand and see what tracks I can get.  If it is a badger path then I’ll be back in the summer to see if I can stake it out and get a picture of an aquatic badger.  Remember, you heard it here first!

I’ve been away for a while with work, so I’m late catching up with my correspondence.  Sheila, Rick and Mrs B – thank you for your comments and apologies for being so slow in replying.  I always enjoy hearing about other people’s experiences, so please keep them coming.

Somewhat accidentally, I now have an international perspective to the blog.  Steve has been kind enough to send pictures from the New York/New Jersey border.  He found the tracks after sighting a fox near his house.

The problem is, they don’t look like fox tracks to me, at least not the familiar British fox tracks.   Fox tracks are small and neat and diamond-shaped.  These are hand-shaped.

I’m not an expert on North American wildlife, but the closest match I can find in the guidebooks is Raccoon tracks.  Does this make sense?  Do you get Raccoons in northern New Jersey?  Do they walk around people’s houses?

This is just my best guess.  If anyone has any other ideas, please do let me know.

For the past week the country has been gripped in a little ice age.  An area of high pressure has settled over Britain, trapping cold air and snow, blocking out the prevailing warm south-westerly winds.  Temperatures as low as -20c have been recorded (my family in Cheshire experienced -14c) coupled with up to a foot of snow.  Predictably, the whole country has ground to a frozen halt.

Personally, the only problem I have with the snow is that I haven’t had enough time to go out and play in it.  Unlike this time last year (see Fieldnotes: 4th-10th January 2009), I’m limited by work and family commitments.  It’s one thing to go out and freeze myself following badger tracks in the snow.  It’s another thing entirely to do it while carrying a five month old baby!  Back in the old days I’d have packed up a tent and sleeping bag and headed out into the woods, just for the challenge of it.  Can’t really justify that now.

Nevertheless, today I drew upon Mid-Bedfordshire’s tradition of polar exploration (there is one, honestly) and went out into the snow to see what is happening.

Here’s some new tracks to have a look at.  These are squirrel tracks.  I watched the squirrel as it bobbed around in our garden and then went out to look at the tracks.  The pattern is similar to that of a rabbit – the same bounding gait – but smaller.

Squirrel Tracks in Snow

I walked on up to the pasture field to look for evidence of the badgers.  The snow last year was a priceless help in deepening my understanding of badger habits and how the local territories interacted.  This year the picture was much more confused.  There was almost a weeks worth of tracks, of animals and humans, and recent falls of snow have complicated matters still further.  Nevertheless, it was possible to trace the movements of individual badgers.  Clearly visible were the patches where they had dug through the snow into the soil.  I couldn’t see any dung, so I assume it was for food.  Badgers don’t hibernate, but they do slow down.  It’s a useful thing to know that badgers will still come out and forage, even in these extreme weather conditions.

Badger Snuffle Hole in Snow

Inside the wood there was more evidence of badger activity.  I didn’t get to visit the sett itself (like I said, there is a limit to how far I’ll take my daughter in these conditions – sturdy girl though she is) but I did add a few more snippets to my badger map of the area.  The wood is criss-crossed by paths, but it is difficult to know for sure that they are badger paths. Very often the only tracks you’ll find on them are for deer.  Today, however, there were clear badger tracks, showing that these are indeed badger paths.  I’ve tried to follow them in the past, as I suspect they lead to the almost mythical ‘third sett’ in the area, but I’ve always lost the paths among the trees.  If the snow persists I’ll have the perfect chance to follow them to their source.

Badger Tracks in Snow

The snow told other stories too.  There were plenty of fox tracks in the field.  They all converged on a post where the foxes had obviously scent-marked.  Just like dogs, I guess.  It’s all part of the territory marking.  Foxes will tend to leave dung in exposed places such as tufts of grass for the same reason.  It’s a nice little insight into fox behaviour.

Fox Tracks and Scent-Marking Post

Lastly, here’s a bit of a mystery.  These tracks were in the middle of the field.  It’s a bounding gait again, with the tracks in groups of four like a rabbit or squirrel, but only a few centimetres across.  The individual prints were not visible in the snow, but the gait can be more revealing.  Something the size of a mouse would surely have burrowed under the snow, not bounded over it.  I’ll need to look this one up, but in the meantime any ideas are welcome.

Unidentified Tracks in Snow

Hope you’re making the most of the snow too!

Once again we’ve arrived at midwinter’s day, and appropriately it’s snowing heavily outside at the moment.  Tonight is the longest night of the year.  After tonight, the days will start to get longer until the summer solstice next June.  Now that I live closer to nature (in other words, in a house with only limited heating) I really appreciate why people have celebrated midwinter for thousands of years.  It’s good to think that you’ve turned the corner of the year.

And the midwinter festival really is ancient.  Contrary to popular belief, Stonehenge was not originally oriented on the midsummer sunrise.  It was aligned on the midwinter sunset.  Every northern culture has its own midwinter celebration.  Our own Christmas is the descendant of one.  When you think about it in these terms, the drinking and feasting and merrymaking isn’t getting away from the true meaning of Christmas – it is the true meaning of Christmas.

It doesn’t feel like a whole year since the last midwinter.  This year has gone by very quickly.  It doesn’t even feel like six months since I was gallivanting around Loch Ness on midsummer’s day.  I guess that a lot of good things have happened since then.

It’s time to make plans for the year ahead.  It’s been a few months since I’ve seen a badger, so they’re definitely on my list, but I’ve got a few more (very) amateur naturalist goals for 2010.  I’ll tell you about these soon.

I hope that you have had a good year too, and I hope the coming year is even better for you.  Happy winter solstice from me, Mrs BWM and baby Scarlett.

Last year I had the opportunity to visit Toronto, in Canada, on a fleeting business trip.  I must say, it’s a very nice city and the people were wonderful.  But one thing puzzled me.  The whole downtown area was connected by miles of subways.  It was possible to walk from one side of the city to other, to shop, to eat, to sit and drink coffee – all underground. It’s a strange subterranean world.  When I commented on this architectural oddity to a local resident she just gave me a knowing look. “When you have six feet of snow for six months of the year, why would you want to walk outside?”

This seems to me to be a very sensible way of dealing with a harsh climate. Unfortunately in Britain we have neither the common sense nor the fortitude of the people of Toronto.  The South East of England received 10-20cm of snow this week and, predictably, everything ground to a halt.  I don’t know whether all the stressed-out workers are looking for any excuse to take a day off or whether we’ve lost any sort of self-reliance,  but either way it’s a pretty poor show.

And me? I love snow.  I like nothing better than getting out and exploring after a decent fall of snow, and since I became interested in tracking I like it even more.  Tracks in the snow offer a real window into what’s been happening, what animals have been out and what they have been doing.  Naturalists have used all sorts of techniques to record the movements of wild animals, from radio transmitters to long pieces of string.  A couple of inches of snow will do the same job in a much more interesting way.

On Saturday I wrapped Scarlett in her warmest clothes and headed out.  I couldn’t take her too far, but we had a nice walk around the fields.  Long enough for me to show her the common tracks in the area.

Here’s the most common – rabbit tracks.  Every now and then I come across someone who says they’ve found strange and enormous paw prints, but what they’ve seen is not the marks of giant toes but the tracks of all four feet of a rabbit.

Rabbit tracks

Which way was the rabbit travelling?  That’s right – left to right.

There seemed to be a lot of fox tracks around.  We live in an area where there is a lot of rearing (and shooting) of game birds, so foxes are not exactly popular.  We used to see far more of them when we lived in London.

Fox tracks are small, neat and diamond-shaped, with four toes and a heel pad.  Notice how the small heel pad forms a straight line at the back of the track, almost like a straight bar.

It can be easy to confuse fox tracks with those of dogs.  Most dog tracks are broader than fox’s, with the toes more widely-spread.  The heel pad is usually larger too.

Dog track - note the wider shape and the spread of the toes

However, dogs come in all shapes and sizes.  Some dogs are bigger than others.  The tracks of small, terrier-like dogs can look very similar in shape to fox tracks.   The way to tell them apart is the spacing between the front and rear toes.  Look at the fox track again.  The front toes are forward of a line drawn across the ends of the rear toes.  In a dog, the front toes overlap with this line.

Fox track - front toes forward of rear ones

Another quick way of telling fox and dog tracks apart is to look at the trail – the series of tracks.  Fox trails always seem to be very purposeful.  Foxes seem to walk in a straight line, one track in front of another.  The tracks have a direct register, in other words the fox puts its hind feet into the tracks of its front feet.  To the novice, it can look as if the fox is walking on its hind feet like a human.

Dog tracks, on the other hand, don’t quite register, so you’ll get front and rear tracks close to each other but not quite overlapping.  Dogs don’t seem to have the same sense of purpose as foxes – dog tracks will often meander around as the dog wanders this way and that.  With a bit of practice you can tell dog tracks from fox tracks without having to look closely at the individual prints.

The temperature hasn’t risen much above freezing all weekend, so hopefully the snow will last for a while yet.  That suits me fine.  Tracking in snow is absolutely fascinating.  Put it this way, if I lived in Toronto I’d happily venture above ground to spend months tracking the local wildlife.

Actually, there hasn’t been any wine.  But I have been getting into the spirit of the season and collecting mistletoe.

I find mistletoe fascinating.  There is such a lot of folklore attached to it, dating back to the Roman Pliny and his account of druids collecting sacred mistletoe from the sacred oak with a golden sickle at full moon, catching it in a white sheet before it hits the ground or else its magic is lost.

The mystery of mistletoe for me was perhaps made greater because it was very rare in the north of Britain where I grew up.  This means that when I come across it in the wild I feel that I have to get a closer look.

Mistletoe is a parasitic plant that lives on trees.  Apart from the obvious traditions of kissing under the mistletoe it seems to fit this time of year very well.  Firstly, it produces its berries very late in the year, so they are out at Christmas time.  Secondly, when the leaves are off the trees it becomes much more visible and obvious as one of the few sources of green foliage in the wood.

Today I took a walk with the family through the woods in Ampthill and I was pleased to see some very healthy bunches of mistletoe on many of the trees.  Obviously the conditions for it are just right in this area.

This may look like a normal tree, but the foliage is actually all clumps of mistletoe – huge amounts of it.  The only other time I’ve seen it in this amount was almost exactly a year ago when driving through Herefordshire.  It’s good to see it here in Bedfordshire too.

Further on down the path I came across a branch that had been blown down in the recent high winds that had a decent clump of mistletoe attached, so now I have some to decorate the house for Christmas.  Picking it from a fallen branch was perhaps not as effective as using a golden sickle, but an awful lot easier.

And yes, before you ask, Mrs BWM and I did have a brief kiss underneath the tree…

Baby carrier and camouflage umbrella - you saw it here first!

Things have been quiet around here for a while.  Actually, that isn’t quite true.  I haven’t been out much lately, but things have been busy at home.  Having a small baby takes up a lot of time, but things are starting to ease up a little.  I’ve also been busy with DIY in the house.  In particular I’ve been restoring our living room door.

This may not sound like a big task, but it’s turned into one.   I thought the door was a fairly naff 1970s one that looked out of place in a 140 year old house.  After some investigation it turns out that it was the original plank-built door that dates back to the building of the house in 1868, but the previous owners had stuck on plywood on both sides to make it look like a 1970s one.  A major campaign of reconstruction and painting, and it’s now back in its proper place – blocking the huge draft into the living room.  The practical upshot of all this is that we can now turn on the heating in the room, so at least we’re a bit warmer.

The other thing that has kept me indoors is the weather.  Like most people we’ve had a lot of heavy rain.  I don’t mind rain too much myself, but it makes it almost impossible to go for a walk with Scarlett.  In her baby carrier she’s exposed to the elements.  I can keep her warm with fleece suits, but I can’t keep her dry.  I don’t think they make gore-tex baby suits yet.

But I think I’ve found the answer.  Being a proper English gentleman I have taken to walking about the countryside with an umbrella.  But not just any umbrella.  I’ve found an American one in Mossy Oak camouflage.

Mossy Oak camouflage umbrella

OK.  So this is probably totally unnecessary.  Having a camouflage umbrella is taking the whole ‘blending into the background’ thing a little bit too far.  Who cares – I like it.

And when you think about it, perhaps it isn’t such a daft idea after all.  I like to think that it isn’t so much an umbrella as a portable hide or blind.  If ever I need to get out of sight of the wildlife, all I need to do is to pop up the umbrella and hide behind it – hey presto – virtually an invisibility cloak!

Whatever.  It means I’ve got more chance of getting outside with my daughter over the winter, and that’s the important thing.