Nest boxes

National nest box week starts each year on St Valentine's Day so it is already long gone.  I had cleared my boxes of the old nests before then and birds are now busy building new ones.  Last year I had 26 boxes.  Checking them earlier this year I found 10 were empty and three nests had been started but not completed (two tits and one tree sparrow). Another two nests were abandoned with five eggs and nine eggs respectively.  Both were blue tit nests and I suspect one parent from each at least had been taken by the sparrowhawk.  This is the nest from the box with nine eggs.

I read recently that cuttlefish can pass the Stanford Marshmallow Test, that is they can forgo instant gratification for a delayed greater reward.  Obviously the same is not true of sparrowhawks as he would have been better off letting the parents raise their young and then eating the fledglings, but perhaps he was just hungry.

Ten boxes looked as though they had seen successful nesting - four tree sparrow, one robin, three blue tit and two great tit.  And the final box had been occupied by wasps.  I remember watching them last summer, and noticing that the wasps were coming out of the back as well.  Here is the wasp nest.

And when I removed it I found they had chewed away the back of the box.  I have rebuilt it with a new back.

I would have thought this box was too small for a wasp nest.  It may be that they moved on to a larger nest nearby (as hornets do, for instance) and certainly the nest was abandoned by mid summer.

After noticing lots of fights over ownership of a tree sparrow box opposite my front door I made two more and put them up close by.  Within minutes both had been claimed by chirruping sparrows, proving perhaps that there is a local housing shortage.  If both end up being used I'll add a few more to this group for next year.

Last year was the first time since it was put up 12 years ago that my camera box had no nest in it.  This was particularly disappointing because I had modified it by putting in a sloping false back wall and moving the camera higher so that it can now see the whole of the nest (if there is one) and the entrance hole.

It did attract interest from a tree sparrow last year but has a 25mm hole plate to keep sparrows out and allow in only blue tits.  I have nothing against tree sparrows but the construction of their nest makes it almost impossible for the camera to see what is going on.

This year I again haven't seen any interest in the camera box, so I am not sure what has changed.  It has been cold recently so that may have delayed the start of nest building but the latest start to a blue tit nest in previous years was on 4th April.  I have eventually decided that the blue tits aren't interested (or perhaps the sparrowhawk has eaten them all) so I have put in one of the left-over nests from last year in the hope that it may attract a tree bumblebee, although it may also be too late for that.  If anything happens I'll post it here.

A big surprise on OtterCam

Or perhaps two small surprises.  I have kept a camera in the culvert all the time, just to keep track of who is coming and going but I wasn't expecting to see new cubs for some months. These are so small that they can't even climb into the culvert and mother had to pull them in.

Once they were safely in the pipe they could only just manage to walk along it.  The mother was constantly turning and waiting for them.  These are the smallest otter cubs I have seen.

I have only just put the ramp back by the sluice and I am so pleased I did.  The cubs are too small to climb the ramp so after checking that the coast was clear the mother picked up the first one by the scruff of its neck and pulled it over the sluice.

She then disappeared, presumably to put it somewhere safe.  The second cub was stuck at the bottom of the sluice and its calls became louder and increasingly desperate.  After what seemed like a long time the mother reappeared and was just taking it up the ramp when the camera reached the end of its 60s recording.

Here's the video.

Paul Chanin's book Otters (2013) says that otter cubs stay in the natal holt until nine or ten weeks of age and don't go into the water until about 12 weeks.  I reckon these cubs can only be about three or four months old - if so they were born round about New Year.  My previous recordings showed the last cub was still going around with its mother on Christmas Day but was on its own by the turn of the year.  So it is just possible that these cubs were born to the same mother as last time if she gave birth around New Year.  If that is the case she would have mated last October and yet the dog otter was really putting himself about in December.  Odd.  I wonder if that dog otter is not the father of these cubs and the mother went elsewhere to give birth to keep out of his way.

These cubs are really too small to be following their mother around.  This all happened at midday so I think the mother was moving the cubs to a different holt - either because she thought they were unsafe where they were or to take advantage of a better location.   I expect she will mainly be going around on her own until they are a bit bigger.  Over the past week the camera showed 12 other traverses of the culvert by a solo otter but I have no way of knowing which one, or whether there is more than one.  However, I did see two otters heading south through the pipe 11 minutes apart which strongly suggests they are not the same animal - in which case this mother will have to be careful as not all other otters will welcome the cubs.  As soon as I see more of them on the trail cameras you can be sure I'll post it here.

The latest from BadgerCam

Life is hard for badgers in this dry weather as earthworms are hard to come by, so they are pleased to have a few peanuts even if it means having their photos taken.  I set up the old Wingscapes BirdCam 2.0 for the first time for a year and a couple of photos on the first night made it worthwhile.

One the second night the badgers were out earlier, when the sky was too bright.  I expect they had remembered where the peanuts were and were hoping for more.

On the third night I moved the camera to a different position, on a well-worn trail.

A badger can always find time for a scratch.

There were many more photos than this but the badgers aren't good at standing in the right place or looking in the right direction.

I think they benefit from having a photogenic background so I have been experimenting each night with different positions under the lime trees.

On the last night the first badger turned up in daylight.

Later there were two and at first they seemed to get on.

Moments later there was a bit of a scrap.  It looks fierce on this one shot and one badger might have got a bloodied nose.  They are usually just snapping at each other, although you can see how they get their scars.  Badgers are mostly solitary feeders but I expect they were both keen to get the peanuts.

Badgers are an easier subject for the trail camera than foxes or otters but it is still satisfying to be able to share their photos because they are so hard to see in real life.  

ShrewCam

The small mammal trail camera has been regularly recording shrews, along with the dozens of mice and voles, both in my garden and at the local nature reserve.  When I looked closely I realised that there were recordings of pygmy shrews as well as common shrews from both sites.

Compared with a common shrew (Sorex araneus), a pygmy shrew (Sorex minutus) is noticeably smaller; has a significantly longer and hairier tail; has two-tone colouring, lacking the paler flanks of the common shrew; and has a rather domed head and a thin pointed snout.  Some of these features are quite hard to pick out on a video, or even on frame grabs, because shrews move at such high speed.  The body weight of a pygmy shrew is 2.5-7.5g and of a common shrew 6-12g.  In the video I have added a bank vole (14-40g) and a wood mouse (13-27g) for comparison.

One advantage of the small mammal camera box is that the animals are all more or less at the same distance from the camera, making a size comparison easier.

In a still frame from the video, this is a pygmy shrew, showing the long tail in the first image.

This a rather blurred high-speed common shrew but you can see the size difference.

On the same scale this is a bank vole.

And a wood mouse.

Fox News

I have been puzzling over what is going on with the foxes in the garden.  Last year was fairly straightforward as the four foxes in the family were easily individually recognisable.  The dog had a torn right ear and a tapered muzzle and a bright white tip to his tail.  The vixen seemed to have shorter legs and a deeper body, so was a very different shape, and had a pale broad muzzle.  One cub had only half a tail (easily recognised!) and the other had a very small grey tip to the tail.  Here are the four last autumn - dog, vixen, full-tailed and half-tailed cubs, clockwise from top left.

Both cubs have stayed through the winter so I presumed both were female because male cubs usually disperse in their first winter.  Both were here in the snow in February.   I have seen the resident vixen from time to time, so she is still around but I haven't seen the dog fox since the turn of the year, nor have I seen another dog fox.  The two foxes I have been seeing regularly in the last few weeks are last year's cubs, now full grown.  And intriguingly the half-tail now appears to be feeding young.  Here she is this week.

And here is the other one I presume to be her sister.

When the two are here together half-tail is the submissive one.  Here she is waiting patiently about 20m away while her sister feeds.  The camera can just about cope with the very low light.

I was puzzled that the full-tail was dominant, even though the half-tail has young (normally a breeding vixen will be dominant and non-breeders will be subordinate).  Then the next night last year's vixen turned up first and she clearly is feeding cubs.

A few minutes later her full-tailed daughter turned up and joined her.  Here are the two of them.

Here is the daughter.

In the past week or so a fox has appeared within a minute or two of me putting the food out.  I think this means the first fox is waiting in the lane and watching until I come back in before dashing in to be the first at the food.  For the past three days it has been last year's mother.

I have rewritten this post half a dozen times in the last few days and I am still not quite sure what to make of it all.  As I understand it there won't be two breeding females within the same social group (family) and it is odd for a yearling to breed when her mother is still here.  I think the most likely explanation is that my garden is in the overlap between two territories and that the half-tail has set up next door to her mother and both visit the garden for food.  So far I haven't seen last year's mother and the half-tail in the garden at the same time so I don't know how they would interact. Whatever the explanation, it does seem there is a good chance I shall see cubs in the garden this summer.