A first glimpse of new arrivals on OtterCam

 

I get to see a lot of pictures like this one above, just half an otter or an otter's tail as it dashes past, too quick for the camera.  When I watched this video from last week there was a big surprise 10 seconds later.

It was surprising for two reasons - originally I wasn't expecting to see them until next month (until they have been seen in the past few days), and when cubs are this young they usually keep very close to mother.  However, these two are very small and maybe they just couldn't keep up. They had certainly never seen a trail camera before.  Here's the video.

Unfortunately the Browning camera only records for 20s at night and the cubs didn't re-trigger the camera before they moved on.  If my calculations are correct these babies are no more than 14-15 weeks old, so only just weaned.  I think the otters probably mated in mid May, meaning the cubs would have been born in mid July.  Paul Chanin's book Otters (2013) says that cubs don't leave the natal holt until 10-11 weeks of age and don't go into the water until they are three months old.  These two obviously can swim already but they are a bit slow and unsteady walking.  I hope to have more news soon.

SardineCam 2

Two of my cameras have been on tour again, this time to Denise and Phil near Riding Mill in South Northumberland.  As before, one camera was set up with a sardine scent lure and the other was in a camera box.  SardineCam was set in woodland edge for the first week and within woodland the second week.  It recorded 1061 videos in all, most of which were of wood mice.  As last time, the mice were fascinated by the sardine smell.  A domestic cat also came by to sniff but the highlight was a roe doe.

Passers-by taking no interest in the sardines were fox, American grey squirrel, robin, blackbird, song thrush and wood pigeon.

The camera box was set at woodland edge in the first week and recorded 546 videos, almost all of wood mice.  In the second week I put it in a rough grass field, still not far from woodland. This time there were only 163 videos and almost all were of shrews - common shrew, pygmy shrew and, most excitingly of all, a water shrew.  There is a small garden pond nearby but the nearest large pond is 160m away across a railway line.  Here are the three shrews in frame grabs from the video to compare their size, body shape and tail length, common shrew above, pygmy shrew middle and water shrew below.

And here is the video.

It was fascinating to find another water shrew away from water, so soon after the one in my garden.  Here is a montage of more water shrew action, all high speed.

If anything the common shrew is even more frantic.  It was interesting to see it collecting the sunflower seeds I had put in.  Shrews are insectivores but water shrews and common shrews both take sunflower seeds in my garden.

The smallest of the three, the pygmy shrew, seems a bit less hyperactive.

We did get a glimpse of a vole but it was very shy and didn't venture past the entrance pipe.  I can't tell what it is with any confidence but from its size I suspect it is a field vole rather than a bank vole.

So no mustelids, which we were hoping for, and no wood mice in the field, but it was great to see all the shrews.  And it is fascinating that moving the camera 50m from woodland to grass completely changes the clientele.  I am not sure it will be worth persevering with the sardine lure but the camera box seems by far the best way to see small mammals.

A few creepy-crawlies

This blog has been overrun by weasels and shrews in recent weeks so invertebrates have barely had a look in.  OtterCam, WaterShrewCam and WeaselCam are quiet at the moment so I have a chance to post a few odds and ends I have come across recently, while looking for something else (usually dragonflies or ladybirds).

The first is a mite, Anystis baccarum, also known as the whirligig mite.  It is a predator of aphids and is available as a biological control for aphid infestations in apple orchards.  This one was munching on an aphid on a gravestone.  The mite is 1.5mm across.

Next a tiny beetle that should be in the list of things that are not ladybirds.  It is Sphaeroderma rubidum, a leaf beetle about 2.5mm long.  It feeds on the leaves of thistles and knapweed.  It overwinters as a larva so this adult won't survive for long.

Another beetle, a Rosemary Beetle, this one about 8mm long.  Although its scientific name is Chrysolina americana it comes for the Mediterranean.  It first arrived in the UK in 1994 and is now widespread.  The larvae feed on rosemary, lavender and thyme.

And a Grey Dagger Moth caterpillar (the head end is to the right).  It overwinters as a pupa so this one won't be a moth until next year.

I have seen a Grey Dagger in my trap before.  While the adult moth is indistinguishable from the Dark Dagger, the caterpillars are similar but not identical.

I expect we'll be back to trail cameras next time.

The weasel leaves a message

It's a smelly old world as far as most mammals are concerned, particularly mustelids.  They use scent to mark territories and to convey and receive information about who's around and what condition they are in.  The weasels that visit the camera box regularly scent-mark with urine and secretions from anal glands but this guy took things a bit further.

SardineCam

A couple of my trail cameras have been on tour - to my friends Gill and Martyn in deepest darkest Hexhamshire.  I took a new camera box for one camera and set up the second with a sardine lure as a new experiment.  Sardines are used by researchers to increase detection of carnivores so I wondered if it would work here.  Hexhamshire is home to polecats (Mustela putorius), one if the UK's most elusive mammals, so one aim was to see if we could catch one on camera.  The more realistic aim was to see what we would find.

The cameras were set for three weeks and at the end of that time both SD cards were full.  The sardine camera had 398 videos and the box camera 498 so I had plenty to look through.  The sardine camera was set up at the edge of woodland with the camera and the sardine can fixed to opposite ends of a piece of wood.  The can was secured with a cable tie.

SardineCam recorded 11 species but only four of those were interested in the sardine lure - the others were just passing by.  The four were badger, wood mouse, magpie and domestic cat.  The badger visited only once but tried hard to get into the can.  The camera gave a great close up of its teeth and claws (with a spider in the top left of the lens).

The magpie visited twice and the first time it managed to peck a few fragments of fish, even though the can was only slightly open (the can is now very visible after badger removed all my camouflage).

The wood mouse visited many times, obviously attracted by the smell but not trying to get at the can.  The cat just sniffed a few times and walked on.

Most of the 398 videos were of American grey squirrels.  Other passers by were blackbird, robin, wood pigeon, pheasant, roe deer, and red fox.

My new camera box was set up at the base of a stone wall.

It had large entrance pipes hoping to entice in slightly larger animals but in the end the only visitors were wood mice, bank voles, common shrews and pygmy shrews.  Here is a brief summary of 498 videos (most of which featured a wood mouse!).

It was very interesting to try out the cameras in a new environment.  The card in the  camera box was full in only nine days so another time I would need a bigger card.  I was hoping we might see a stoat or a weasel and I still have polecat on my wish list.