Otter advice

[jennyb]

I mentioned in the mammal of the day thread a week or so ago that I had seen an Otter by the pond in my garden (quite a long way from the house). I have spent some time watching and also looked around for spraint but so far have seen/found nothing. I just really wanted some advice as to whether it is likely that the Otter lives there or was just visiting, or whether it was maybe a Mink instead.

When I saw it the light was fading, I was not wearing my glasses and didn't have my camera with me! However the shape was distinctly Otter-shaped and it seemed at least a metre long so it seemed too big for Mink. I could not really make out colour because of the light.

It seemed to poke its head out of the ground between the 2 walls of the dam that forms the pond before climbing out. I am showing a photo here of the dam taken last year during the big flood. The water is usually at least 1 metre lower than the top of the dam, so it is not normally flowing over the top. It just happened to be the only decent photo I have of the dam wall.



I have found 2 holes in the soil in the top of the dam which are possible candidates. One is obviously in regular use but seems too small. The other is about twice the size but does not seem to be in regular use. Question 1 - what diameter is the entrance hole to an Otter hole likely to be? The hole in question (see photo) is about 5 inches diameter, probably too small for an Otter, but does not look particularly like a Rabbit hole. Question 2 - is this a likely location for an Otter holt?



The nearest river is about half a mile away as the crow flies so it is possible that it was just exploring, but it really did look as if it was climbing out of a hole in the dam.

I have had my stealthcam set up every night but have not captured anything except muntjacs and Roe deer, but the motion detector does not work well for small/low lying creatures.

I am racking my brains to think of a way to get my webcam set up there, but the wireless transmitter needs to have line of sight to the receiver, which in turn needs to be in the house close to the computer. The pond is just too far away and also down a hill away from the house. Any repeater to boost the signal would have to be weatherproof.

Any opinions/suggestions would be very welcome.

Jenny

[mh68]

Quick question Jenny - was your sighting either during, or following a spell of heavy rain? I`ll have a think about your other points ,although i`m certainly no expert on these creatures....

Mark H

[jennyb]

Originally Posted by mh68

Quick question Jenny - was your sighting either during, or following a spell of heavy rain?

Mark H

No, it was just after that very hot spell we had here a couple of weeks ago. However, I believe there was a huge amount of rain the previous week while I was away on holiday.

Jenny

[mh68]

Right. The reason I asked was that during such times they can travel far and wide, and turn up out of the blue in unusual places, then disappear again just as quickly.If it was as large as you say then that rules out Mink.Then again,half a mile isnt very far really for it to come from the river, even on the same evening you saw it.
The hole in the pic you posted is too small for Otter i`d say, it would be nearer a Fox/Badger sized entrance if that were the case, and its also a bit open and exposed for an Otter holt.
Bear in mind too that Otter spraint isnt always as obvious as Fox scats etc...often all you`ll find are very small fragments.

Mark H

[jennyb]

Yes, I thought the hole was too small, but it really did seem to come up out of the ground around that point. As I mentioned there is another hole which is much bigger but does not seem to be in use. Maybe I should spread some sand or soil around near the holes to see if I can get any tracks.

Jenny

[mh68]

Originally Posted by jennyb

Yes, I thought the hole was too small, but it really did seem to come up out of the ground around that point. As I mentioned there is another hole which is much bigger but does not seem to be in use. Maybe I should spread some sand or soil around near the holes to see if I can get any tracks.

Jenny

It wouldnt do any harm Jenny - you never know until you try...

Mark H

[deer boy]

Why not put some food out & set up some sort of hide & wait & see if you see anything.
It would be well worth the effort if it is an Otter

[mh68]

Jenny, regarding the size of holt entrance Otters can use, I was chatting to a mate on msn last night and he pointed out that they`ll happily use something the size of a large Rabbit burrow so my suggestion was a little bit out. Sorry.The other points are still relevant though..

Mark H

[coasty]

I would be wary about discounting Otter because of the size. A few years ago a fishing club I was a member of was losing trout from the rearing ponds we could see the leftovers and footprints every morning but could see no holes in all the fencing and netting,, We eventually recorded the Otter getting in through the 4m long 100 mm diam drain pipe that was used as an overflow pipe....
Otters usually like to have their permanent holt entrance well concealed, I beleive they will use any animal burrow etc suitable as temporary accomodation whilst exploring their home range...

[mh68]

Originally Posted by coasty

Otters usually like to have their permanent holt entrance well concealed, I beleive they will use any animal burrow etc suitable as temporary accomodation whilst exploring their home range...

Thats exactly what I was told by my mate. A 4 inch pipe must have been quite squeeze for the poor `ol Otter

Mark H

[jennyb]

Thanks everyone. The sides of the hole have the grass pushed really hard back against the sides as if someone had a really tight fit - so maybe!

It is also a very secure place for a holt because it is between 2 concrete walls with just access from the top. Maybe we should let the grass grow a bit longer on the top of the dam to be more secure.

Deer Boy, I have already put up a hide but I don't have a great lot of time to sit in it. I work as well as being a carer so my free time is limited. It was around 8.45 when I saw it so I have been looking around that time each evening. Does anyone have any idea the most likely time for it to appear?

What do you suggest for bait, Deer Boy? Fish, I guess, but what kind?

Jenny

[deer boy]

Hi Jenny i just did a quick search & found these work Otter LURE,SALMON PASTE,CARP,SARDINES but i'm sure any fish would work hope u see it again soon

[mh68]

You could try something natural like Trout,Eels or Roach, go to a local angling shop, they usually sell frozen freshwater fish like these for baits for pike fishing.
I`ve not heard of anyone trying to attract Otters with bait though, so i`ve no idea if it`ll work or not.

Mark H

[Uncle_Filthster]

Wild ones tend not to take deadbait. Just keep toot for Otter signs, they stand out like a sore thumb once you recognise them. Spraint or a track is the best indicator and once you've had a sniff of spraint you'll never forget the smell

If it had a long tail it was most likely an Otter but probably a transient young male moving through.

[eeyore]

Originally Posted by jennyb

I am racking my brains to think of a way to get my webcam set up there, but the wireless transmitter needs to have line of sight to the receiver, which in turn needs to be in the house close to the computer. The pond is just too far away and also down a hill away from the house. Any repeater to boost the signal would have to be weatherproof.

Any opinions/suggestions would be very welcome.

Jenny

I would suggest a long usb lead rather than relying on wireless which can be a bit dodgy at the best of times - you can buy 100ft usb leads in staples etc (not sure about the max length you can clip together tho).

alternatively I seem to recall that last year you had one of those IR trigered trail cams which you used to take stills of deer in your garden - if you still have it how about using that ?

[paulthomas]

Originally Posted by eeyore

alternatively I seem to recall that last year you had one of those IR trigered trail cams which you used to take stills of deer in your garden - if you still have it how about using that ?

Quite a few researchers are attempting to use trail cams for Otters, often with no success. The Otter just doesn't seem to trigger the sensor. My theory is that this is because the Otter's fur is such a good insulator and the outer fur is usually cold and wet and this combination just doesn't give enough thermal contrast to trigger a passive IR detector. There's also a potential legal issue if the camera is placed near the holt as it may class as disturbance and thus contravene 9.4(b) of the Wildlife and Countryside Act 1981. Overall I feel that if there's an obvious run which the animal is using then something like sand to get definitive footprints might be the better idea.

[jennyb]

Yes, whatever is using the hole is not triggering my stealthcam. Creatures low to the ground don't often trigger it. I only manage to capture the Badgers with it sometimes and only if I have it very accurately pointed to the food I leave out for them.

About the longer lead - I think 80 metres is about the maximum and I would need at least 120 metres.

I have now located a spot to place the webcam which may possibly have line of site to one of my bedroom windows (but through the trees). I would then have to have a cable from the receiver down the stairs and into my office - sounds a bit precarious. Tomorrow I am going to see if the wireless will transmit that far - I am not hopeful!

I think sand may be the answer.

Jenny

[mh68]

Originally Posted by jennyb

I think sand may be the answer.

Jenny

I`d tend to agree. Even better than sand would be something similar to the Mink rafts put out around Water Vole sites - the material used for collecting the tracks on these is very sensitive and even small mammals such as Woodmice leave tracks very clearly.I think it`s clay based.
Might be worth dropping Kate (vole-woman) a pm and asking how they make theirs...

Mark H

[mh68]

Jenny, I found this link which explains how the substrate used to record tracks is made, hope its of use....

http://www.gct.org.uk/uploads/minkrafthighres.pdf

Mark H

[jennyb]

That's very interesting, Mark. Although I would not want to trap anything, it is a great way to collect tracks to see what is visiting the pond. I really have not spent much time investigating the pond creatures.

I put out a little bit of sand last night and there were tracks this morning but I think they were the moorhen! However, it did prove that sand is not a very good way of showing tracks. This clay sounds much better.

Many thanks,

Jenny

[mh68]

Sand will pick up tracks fine from larger creatures, but the clay method will give you a much more accurate picture of whats around, as it`ll record prints from creatures as small as mice/shrews to the larger stuff. You never know, even if you dont find Otter prints, you may discover something else using the pond that you didnt know was there

Mark H