OtterCam in the pipeline

Back in March I had a grand plan to video the otters catching frogs and eating them in the culvert.  It didn't work out because, unlike previous years, they caught very few frogs and didn't eat them in the culvert.  As part of the plan I crawled up the culvert at the beginning of March and fixed a trail camera to the roof to record from inside.  Soon afterwards we had heavy rain and there was too much water for me to risk going back in to retrieve the camera.  It was over two months before I could get it back.

I posted previously the videos from outside but here now are some from inside the culvert.  First a short compilation.  It starts with mother and one cub before the rain came, then a few clips with deeper water, so you see why I couldn't get back in (even the otters find it slippery).

Originally the other two cameras were on posts a few metres downstream but as the water subsided I moved one back to the downstream rim of the culvert.  It shows how unconcerned the otters are about the cameras, usually just sniffing as they pass.  And how the camera can be slow to react to a trigger, apparently not "seeing" the otter right in front of it.  As the camera is 120mm (5 inches) high we can also judge the height of an otter - it is small.

Lastly I was able to re-edit a video of the mother and two cubs fishing.  I posted this previously with views from only the downstream cameras.

The cubs have now left their mother so the cameras are only picking up solo otters at present.  I hope the mother will produce more cubs this summer so we may see them appear on the cameras at the end of the year.  I think the culvert roof camera has some potential, although I need a better way of getting it in and out.  Also I need the otters to read the script and eat the frogs in the culvert.  Maybe I'll try again next year.

A sinister visitor

 

My new bee house is covered in a wire mesh as protection against birds but it is no match for this predator.  This is a female ichneumonid wasp, a parasitoid of solitary bees, possibly Ephialtes manifestator, although ichneumonids aren't easy to identify.  I first saw this one with her very long ovipositor already through the mud seal on one of the completed red mason bee nests.  She was constantly twisting her body to manipulate the tip of the ovipositor by feel to penetrate one of the cells inside.  Once in she lays an egg which will hatch and the larva will devour the bee larva and all the stored pollen and nectar in the cell.  It will then metamorphose into a wasp and wait until next spring to emerge, along with the surviving bees.

At one stage the ovipositor was in up to the hilt (40mm or so) so it may have penetrated more than one cell inside.  The ichneumonid was already in position when I noticed it and it was over 75 minutes before it withdrew, showing extraordinary patience.

Then it was sniffing around the other cells, looking for another opportunity, bending its antennae like this as it probed the mud seal.

At one stage it was considering this blue mason bee nest but couldn't see what I could see, that the completed nest is only half full and the cells would have been out of reach.

The next day it was back, this time attacking a red mason bee nest in the observation section.

After selecting the target it withdrew the ovipositor from its sheath and very carefully probed the mud seal.

And after only two minutes it was through.

Then it spent another 59 minutes trying to get past the second wall but failed, and eventually gave up.

I had thought the empty chamber, which is often at the front of the nest, to be a defence against birds but it will be equally effective against this kind of attack.

There are lots of other parasites around the bee house.  Some, such as this Sapyga quinquepunctata, a parasitic wasp, sneak into an unfinished nest to lay an egg while the owner is away.

Ichneumonids wait until the nest is complete and the host larva is growing before they attack. Another one I see quite often is Gasteruption jaculator which is smaller than Ephialtes manifestator and has a shorter ovipositor, probably targeting small solitary wasps and bees.

News from the pond

My new meadow pond hasn't featured on this blog before but now there is news.  The pond was dug at the beginning of last year and is designed specifically for dragonflies.  It is shallow, in full sun and is in the middle of the meadow (which also hasn't featured on the blog but will do soon). Now at last I have exciting visitors, broad-bodied chasers, which are often the first dragonflies to visit a new pond.  At the beginning of the month I saw this male.

And a week ago a female.

Then three days ago a male and a female sitting on the same stick less than an hour apart.  Now I just need them both to turn up at the same time, although it may already have happened.

Last year I did see an occasional damselfly in the meadow and a few common darters in late summer but that was all.  There were obviously more than that because this year there are dozens of damselflies emerging from the pond and flying around the meadow (damselflies take only one year to develop whereas dragonflies take two or more).  This is a male large red damselfly.

And a male azure damselfly.

And this is a newly-emerged azure damselfly next to its exuvia (larval skin), preparing to take its first flight.

And an ovipositing pair of azure damselflies making sure I will have more next year.

If you look very carefully you may be able to make out the dragonfly at the top of the stick in the centre of the photo.

Fox News

My local foxes last featured on the blog in February.  Back then a new alpha pair had taken over the territory.  One was very pale and the other richly coloured and I hadn't worked out which was which (and in fact I guessed wrong).  Their routine was different and they weren't turning up early which meant that the rats were getting to the food first so I stopped feeding.  A couple of weeks ago I saw a fox trotting down the drive at dusk so I decided to try feeding again.  The two foxes are now both keen and often arrive before it is dark.  The blonde is clearly the alpha female and she is obviously feeding cubs.  Her colour and her torn ear make her very easy to recognise.

The dog fox is more richly coloured and has no obvious marks or scars.  He is a much more relaxed character than the previous dog and will often lie down to eat.

On the couple of times I have seen them together the dog has been unwilling to share (notice the tail curl in the photo which means keep off).  The female either sits and waits or goes away to come back later.

The vixen is usually here first.  Two nights ago she was here well before sunset allowing me a few photos in natural light.

The previous fox family included various different relatives over the two or three years but so far this year I have seen only these two.  My hope is that they will be joined here by their cubs later this month.  

Rescue mission

We were supposed to be counting bees but I got a bit distracted by dragonflies (it happens). Then I was more distracted by something in the water.  As I wondered what it was it started swimming towards me and I realised it was a bat.  I think it was swimming batstroke.

When it reached the bank I reached down to scoop it out.  It was soaked through and was happy to sit on my hands at first, before climbing up my shirt.

The bat seemed healthy but was wet through and was not inclined to fly.  When it had dried out a bit I put it on the trunk of a large oak tree and it climbed steadily, eventually going up out of sight. My hope is that it was warm and dry enough and high enough to fly, although it may have decided to wait for dark.

Having read it up since I got home I am not sure I should have released it.  I found advice about grounded or lost bats on the Bat Conservation Trust website, although I don't think this one was in either of those situations.  

I didn't know bats could swim but then most, perhaps all, mammals can.  It is unusual for a bat to be out in the middle of a sunny afternoon but it can happen if it is hungry.  Although I didn't see it flying I wonder if this one was hunting over the pond and made a misjudgement to crash into the water.

A surprise in the meadow

I have been caught out a few times before so I always check the coast is clear before I put out food for the foxes.  This time I looked through the kitchen window and thought the fox was here early.  Then I looked closer and saw this.

There was just time to grab the camera for a couple of shots before the buck moved out of view. I don't know how long it has been here or even if it is still here.  The top of the garden is pretty overgrown, deliberately left wild for things to live in, but I wasn't expecting a roe buck.  I am not even sure how it got in.  In previous years I have left the gate open for the deer in late winter or early spring but they have always left in early morning.  It would be possible for a roe deer to jump the 4ft gate but there isn't much of a run up.  The lowest fence is 4ft as well but it is nearly all overgrown with hedges.  If the buck stays I hope it doesn't eat too much of my meadow.

Emperor moths

The Emperor Moth pheromone lure is amazingly potent.  I have tried it out twice this year and each time it produced six male moths within a few minutes.  The first time was at Hepple, west of Rothbury in Northumberland, on the heather moorland near the border with Harwood Forest. The lure is hidden under the bark of a bit of dead wood.  To start with the moths were flapping around like crazy, making it almost impossible to get a photo.  Then one settled on the wood very briefly,

and another landed in the heather nearby and stayed still for several minutes.

A few days later I took the lure to Edmonbyers Common in County Durham.  This was old scruffy heather but the moths arrived within a couple of minutes.  Here you can see three with the pheromone-impregnated lure tucked under the bark.

Here are two fighting to get to the imaginary female.

They are very excited when they arrive but sometimes seem to get tired and just stop for a rest, which makes the photography much easier.  This one stopped on the wood for several minutes, probably exhausted.

It has amazing feathery antennae to pick up the faintest scent of a female.

Eventually I picked it up to be out of the way of the others.  I had taken great care not to get any pheromone on my hands but it was a cold day and the moth seemed happy to be on my warm hand.

I found another rather faded and tattered moth in the grass a metre or so away.

And another worn and tatty individual.

I have yet to see a female Emperor Moth.  She is larger and has the same markings but the background is pale blue-grey, even more beautiful than the pink-brown of the male.