All change on OtterCam

A lot has happened since my most recent post on the local otters.  Last time the camera had shown an encounter between the dog otter and the female and cubs.  A few nights later they met again but the dog was much more forward, although at that stage the female was still discouraging him.  There was a lot of chasing going on and much of the action was off camera so it isn't easy to make a coherent story out of it but this video gives the flavour.

That was the last time the family were together.  Within two days the female was very noisily and excitedly chasing around and obviously encouraging the dog otter.  As far as I can see from the cameras the courtship went on for about three nights but they only sporadically appeared in front of my two camera positions.

Since then mostly only single otters have appeared on the cameras.  My impression is that the mother abandoned the cubs, rather than them leaving her, as for a few days one or both were showing up and calling for her, probably trying to work out what was going on.

There have been two episodes that I can't quite work out.  In the first, one otter (a male) was rolling and grooming for several minutes at the water's edge whilst another (squeaking) was mimicking its actions only 2-3 metres away.  Obviously the first knew the second otter was there but didn't acknowledge it.  When the first otter left the second came down to roll in the same place before following into the water.

Then a similar episode a couple of nights later and eight days after the noisy courtship started. These two seem to be getting on pretty well and I presume they are the dog and the female, still together.  They were certainly spooked by something at the end although nothing appeared on camera.

The recent otter family has been the most exciting to follow so far.  I hope the female will now be expecting more cubs in two months time and with luck they will appear on camera around October.  I'll keep a couple of cameras out all the time to check on what goes on.

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My very first home-grown dragonflies

This is something I have been looking forward to for ages.  This morning I saw the first dragonflies to emerge from the pond in my meadow.  The pond was dug in early 2022 so this is its fourth season.  In 2023 and 2024 it produced large red damselflies and azure damselflies. Also in 2023 I saw, separately, male and female broad-bodied chasers perched beside the pond. I hoped, but wasn't sure, that they had found each other and that I might see dragonflies emerge this year (the nymphs take two years to reach maturity).  Early last year I partially drained it to deepen one end and while doing so I found several chaser nymphs so things were looking promising.

I have been checking the pond each morning for the last few days.  I noticed large red damselflies two days ago and azure damselflies yesterday.  This morning I spotted a dragonfly nymph at 07.30, low down on a stem but accessible to a camera.

At 09.00 it climbed a bit higher and gave me a better view so I settled down to watch.  Despite the sunny forecast it was a cloudy morning and the light was poor so I used flash for most of the photos.  The nymph began to split along the back of the thorax at 09.25.

Then the dragonfly heaved out its head, thorax and most of the abdomen and hung upside down of several minutes.

At 10.02 it suddenly swung forward, the legs grasped the exuvia and the rest of the abdomen came free.

Then began the slow process of expanding the wings and abdomen.  I could confirm by this stage it was a female broad-bodied chaser.  It was interesting to see how rapidly the colours were changing as well.

At 12.13 the wings suddenly clicked open.

Ten minutes later I was surprised to see the wings closed again.

By 12.47 the wings were reopened and stayed that way.

The dragonfly climbed to the top of the plant and flew off at 13.10, three and three-quarter hours after the whole process began.

While she was still expanding her wings the dragonfly shifted position and as I moved to get a better view I noticed another one only about six inches behind her but more hidden in the vegetation and a bit behind in the process of eclosion.

After the female had gone I switched attention to the second dragonfly and could see it was a male broad-bodied chaser.

Eventually it also climbed higher before flying so I could get a better view.

While I had been watching these two a third newly emerged chaser, another female, flew into the grass at the far side of the pond and, after fluttering for a few moments, flew up into the trees. Broad-bodied chasers are rather like London buses - you wait ages for one and then three come along all at once.

The female will remain yellow but will become broader and darker with age.  The male's abdomen will quickly become royal blue and then turn pale powdery blue as he reaches maturity. Newly emerged dragonflies fly away from the water and spend a few days hunting, feeding and gaining strength and maturity.  The males return to hold a territory and the females come back to the water to mate and lay eggs.  I'll be keeping an eye out for them.  And don't worry, there will be more otter news here soon!

WeaselCam in April

Three weasels were recorded in the camera box last month.  This handsome male is not one I have seen before but he visited only once.  I have added a slow motion replay at the end of the video to get a better look because he moves so fast.  He looks a bit lighter in colour than most.

Two females turned up in April, again both new to the box.  This one came several times over a few days.

She gave a very good view of her gular (under chin) spots so I can be sure she is new.

The other female ran through only once but even so I can see her gular markings are very different.

There have been very few mice and voles in the box so that probably explains the relative lack of weasels compared with this time last year.  I hope the voles will move in as the meadow grows and attract more weasels and kestrels.

Bad news on WaterShrewCam

Bad news if you are a water shrew that is, but maybe good news if you are a heron.  The trail camera saw two shrews being eaten by a heron last year and another a few weeks ago in a blog I wrote for the Natural History Society of Northumbria.  Then last week the heron(s) caught and ate nine water shrews in six days at only one camera position.  I thought water shrews were uncommon but there must be a healthy population to sustain that level of predation.  Or at least there was.

And a bonus heron video.  Last month I posted a video of a heron that caught a frog that put up a good struggle and eventually got away, probably not unscathed.  This time the heron caught a toad.  The toad's defence is to swell up and produce a foul-tasting and perhaps toxic secretion from its back.  The heron seemed to realise pretty quickly and dropped the toad before trying to wash the taste away.

After that I think the heron will stick to water shrews, while there are any left. 

A Brief Encounter on OtterCam

Just one video this week but it shows something I haven't seen before.  Watch the video first and I'll explain afterwards.

The dog otter had hauled out onto the bank for a bit of rolling and scratching.  At first he thought he heard something but then wasn't so sure and resumed his grooming.  Then he was sure he heard something and three other otters appeared, very probably his mate and offspring.  It is fascinating to see how submissive he was, and how the cubs were curious, but not overly so. The dog watched them go and then followed them up the bank before returning alone four minutes later.

I presume they have bumped into each other before and they will certainly be aware of each other through scent-marking.  The audio isn't very good on this camera but the encounter was almost silent - just a few soft squeaks as the family approached.  It confirms that the cubs aren't yet mature enough to leave and the female is not yet interested in mating.  Although the cubs are big they are only about 9-10 months old so I expect them to be around for a few weeks yet.

Snakes in the grass II

Another trip north to see the snakes, just before the grass gets too long to see anything.  By now the adders have shed the skins with which they emerged from hibernation.  This time I saw four adders and I think three were males.  The best of them, resplendent in black and silver, lay out in the sun but he warmed up quickly and was soon gone.

The others were more tangled in the grass and were still toasting themselves when I left.  This one is probably a female, judging by the brown colouring.

And two more rather shy males.

I think that is it for my snake-watching this year, unless I have a lucky encounter with an adder (or grass snake down south somewhere) while out looking for other things.

Non-target captures on OtterCam

The otter family has been keeping a lower profile recently.  At one stage they were absent from the cameras for a week, possibly because the mother is taking the cubs farther afield to show them that there is more to the world than one lake.  They also haven't shown up much in daylight recently but here's a little night-time wrestling match between the two cubs who seemed to be taking it very seriously.  They are now bigger than their poor mother and I think she got a nip at one stage.

At present fewer than 1% of the trail camera recordings show otters.  Many of the others are of non-target species, especially moorhens, water rails, coots, robins, reed buntings, dunnocks, blackbirds, herons and wood mice.  Last week there were three notable captures of non-target species.  First a common snipe with the added bonus of a Cetti's warbler singing, a little grebe and a bumblebee on the audio track.  I even heard and saw the Cetti's when I was checking the cameras.

Then a stoat, first in daytime and then at night.  Being a stoat it was too fast for most of the cameras but this is what they saw between them.  It is interesting that the stoat is aware of the cameras switching on in the dark.

Thirdly a badger who was very aware of the cameras switching on as well.  The Cetti's warbler was singing in complete darkness.

The reaction of the stoat and the badger to the cameras is interesting.  The first time a trail camera switches on at night there is a click from the mechanical infrared filter moving into position but these weren't the first recordings of the night which probably shows that both animals can see the low-glow (850nm) infrared light.

I am having big problems with false triggers on the cameras in their current positions - recordings made when there is no animal at all.  It seems to be caused by the waving shadows of the reeds on sunny days and because of the cameras' positions there isn't much I can do about it.  It fills up the cards and runs down the (rechargeable) batteries so it isn't the end of the world but it does mean I have over 1000 videos to look through each week.

Finally a little bonus from the mallards, who never seem to look where they are going even in daylight.

News from WeaselCam

It has been a quiet start to the year for my camera box.  The camera has been in place all the time since last March with a peak in weasel activity late last summer.  There was only one brief visit from a male weasel in January this year, one even briefer visit from a female weasel in February and a glimpse of a male stoat that turned round in the entrance in March.  Here they all are in the video - don't blink.  And although the images are blurred, notice the size difference between a male and a female weasel.

A recent paper by Croose et al looked at how well the Mostela (a professional camera box similar to mine) performed in detection of weasels and stoats compared to an external trail camera.  It found that weasels readily entered the box and were detected by both techniques. Stoats were rare and never went inside, which tallies with my experience here.

Non target species have been plenty.  I posted videos of pygmy shrew, common shrew and water shrew in January.  The camera has also seen field vole, wood mouse, American grey squirrel, robin, wren and great tit.  Here is the pygmy shrew - the pipe inner diameter is about 48mm so you can see how tiny the shrew is.

The presence of voles is encouraging as they are the main prey for weasels but the voles only appear in the box at night and the weasels are strictly diurnal. 

Weasel territories are about 1-10 hectares for females and 2-25 hectares for males, while stoats' territories are typically larger, varying from 2-124 hectares for females and 8-256 hectares for males.  That means my patch is as little as 2-5% of a weasel territory and even less for a stoat so it is no surprise that they aren't seen here very often.  I hope when the meadow grows up in the next few weeks the voles may move back in and attract more weasels.  We'll see.

A very narrow escape

I am not an expert in swallowing live frogs but I think the trick is to get it turned round so it will go down head first.  This young heron made a rather inelegant flop into the reeds to catch a large frog but then didn't seem to know how to deal with it.  The poor frog got rather mauled about as the heron was trying to work out how to deal with it but eventually took its chance to leap to freedom.  The heron spent another minute gazing at the gap in the boards just in front of the camera to no avail.  Despite its escape I fear the frog probably didn't get away unscathed.

Another example of the fascinating non-target videos that turn up on OtterCam.  I expect we may see otters with frogs soon as March and April seem to be the season for them.  Otters are also rather more effective in dealing with frogs.

Relaxation on OtterCam

Otters rely on their dense waterproof coats to keep them warm in the water and they spend a lot of time keeping their fur in tip-top condition.  The parts within reach are groomed but it is hard to scratch your back when you have short legs.  The solution is to roll on something comfortable such as grass or moss.  It looks as though they enjoy it and it is certainly enjoyable to watch. This is the dog otter looking as though he is having a good time.  I love the way at the end of the video he seems suddenly to realise we have been watching him.

Grooming seems also to be a social activity as the family all get involved at the same time.  This is the longest video I have posted but is relaxing to watch - perhaps the otters' equivalent of slow television.  I hope you enjoy it.

Snakes in the grass

Spring equinox, so time to look for adders.  But it was a big surprise to find that the last time I was there was five years ago, just before lockdown.  The forecast was for a cold sunny morning which would have been ideal but it turned out misty and hazy and the sun barely showed.  Still, the adders did come out in the hope of soaking up some warmth.

They lay on the bank, facing where the sun should have been.  To start with I had trouble finding one - they are camouflaged after all - but once I got my eye in it was easier.

I think most I of those I saw were males but it isn't easy (for me) to tell males from females before they shed their skins after emerging from hibernation.  Females are larger and brown/dark brown while the males are smaller and will eventually be silver and black.  I think this is a male.

And this might be a female.

The snakes regularly adjust their position to try to absorb more warmth.

There are two snakes here, coiled together.

These are well arranged to maximise heat absorption although it can be difficult to tell which end is which.

If I get the chance I may go back next month after their first moult, although the vegetation grows up quickly so they can be even more difficult to see.