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.