Otter latrines

[looknlisten]

Hi,

New to here but have been reading lots here for a long time.

I live close to a smallish river that has crayfish and some fish in it, there's a lane/bridge crossing the river that's built up each side with large stones with lots of large cracks and crevices that go quite far under the lane and ground.

And just recently right beside a hole(about the size of a large orange) in the stones I've noticed what appears to be a latrine of some kind, the pile is about 10inches by 10 and appears to have a mix of older and somewhat fresh scat of some sort of animal.
Its quite a big pile and is broken and crumbly so the size of individual poo's is hard to tell, smell wise there doesn't seem to much smell of it maybe a slight musky/fishy smell.

So I was wondering do otters use a latrine several times like this and would it be so close to a bridge and entry or exit hole?
Also apart from otter what else could it be? I had thought of mink but it didn't seem to smell very bad.

Thanks and any info would be appreciated.

[The Woodman]

Hi lookanlisten and welcome to WAB.

From what you describe, it does sound like an otter spraint midden although there is another possible explanation.

Otters can use these heaps that may have been there for many years and they play an important part in communication between animals. Individual scent is left with every spraint that will inform other otters who are attracted to the midden as to the presence, sex, and breeding status of an individual.

These are usually left in prominent places as your bridge foundation is, on the otters route. Bridges are good "pinch points" constraining the otters to pass between a narrower width of their chosen habitat.

The oldest spraints will weather and appear as a grey dusty mass with visible fish bones, scales and possibly crayfish shell parts. Fresh spraints vary from a spot of black or green jelly with no content to a finger sized job crammed with fish bones.

I have seen spraint middens three feet high on small islands off your west coast that must have developed over hundreds of years.

The orange sized hole sounds about the smallest size that an otter could normally get in.

The other animal you say it might be is mink. I would doubt a mink would leave such a big heap but it is not impossible. Mink scats are distinctive in two ways - conformity and smell. Always much smaller in diameter, twisted and drawn out. They generally remain longer in their form as usually comprising more fur and feather to form a cohesive matrix.

As many will say, an otter spraint smells not unpleasant but a distinctive musky, fishy scent. There many analogies. Mink scats smell awful - on par with fox.

Mink usually bring their prey to shore to eat it and where crayfish are present, piles of shells, legs and antennae will be found. Carapaces can be found with small teeth punctures.

Mink also love rock piles and it is far more likely to see an animal in daylight on such a place.

I'd go along with otter, are you in a position to post a picture of the heap?

[vole-woman]

Fantastically informative answer, Woodman. I always check under canal bridges round here for spraint, and I usually find it too.

[The Woodman]

Thank you vole woman. During the rush to type over my breakfast I omitted to say that some jelly spraints are totally clear which I think are just scent bearing mucus in the absence of passable faecal matter.

The canal scenario is interesting - did the Border Counties Otter Hounds ever hunt the canal??

I've looked at several sites on the Lancaster Canal last year and only found one positive site on the towpath side. As always, the other bank looks better!

Amazingly the only smilie to have dissapeared is the yellow one - where's it gone? Just a square with a dot in the middle left.

[looknlisten]

Thank you for such an detailed reply,

I hadn't my camera with me but I'll try to get out today and get a few pics, the pile appears quite new, maybe around the two weeks mark as I was standing where it is just a few weeks back.

When I get a picture I'll post it.

[looknlisten]

Here are a few pictures, I had a quick look but can't see any scale's or fish bones but there seem to be a lot of red/brown bits through it as you can see in one of the photo's.
There seems to be a little more smell today, its not what I'd call pleasant but not terrible, kinda fishy.

The first photo shows the hole at the top, it seems quite small so if it is an otter it wouldn't be a very large one.

[The Woodman]

Thanks for the images, looknlisten.

I'll tread with caution here as it's difficult to scale the scats/spraints but I think it may be otter. The pink coloured matter is almost certainly crayfish remains unless this site is near the coast. There are a couple of darker spraints on top of the pile that look reasonably fresher.

The hole looks to be too small for otter use but there again, difficult to scale but I'll take your word for its size! It appears to be well used and in the portrait image the size can be judged by the spraints.

What ever is using this area it's doing it regularly. Are there any prints in mud/sand nearby or other spraints on features up or downstream?

If you can bear to do it, have a closer look at a couple of recent pink spraints. Pull them apart with a couple of sticks and see if you can see crayfish / prawn legs and antennae. If so, then they'll be otter rather than mink who tend to leave the legs and other bits at the feeding site.

It's an interesting one and perhaps you'll get others' views.

I'm not suprised it smells fishy!

[The Woodman]

These are the remains of a freshly killed and eaten signal crayfish. These are much bigger than native white - clawed crayfish and proof that they can't be chewed and swallowed in one!

[looknlisten]

I actually already had a good look through some this morning (don't worry I'm not squeamish) I looked through both fresh and older and could see little to no evidence of fish, maybe a few scales but I did find lots of shell both pinkish/red and brownish coloured pieces and one lower section of leg.

It doesn't hugely surprise me that there are very few fish pieces as although there are fish in the river there isn't a very large amount and most are of a smaller size.
I also noticed that there were no signs of hair,fur or feathers so I'll also take that as a good sign that its probably not mink.

I could see no sigh of prints on the river bank but its been very hot and dry here for the last while so there is not much wet mud around.

Regarding the hole it is small but of an irregular shape so maybe with squeeze a small otter may fit or it may be just where it was scratching at it to try expand it to fit.

Another clue is that the fresh spraints that are shown in the photos are today already changing colour and gone quite hard and brittle.


I'm very at home in nature and have a quite good knowledge of it but otters are something I don't have first hand experiance of so its great to hear from someone who has.

I just hope that if there are otters that they'll be okay as unfortunatly in this rural area there is little respect for nature/wildlife and its such a pity because this area has a great range of wildlife.

Thank you for all your helpful information.

[The Woodman]

Keep your eyes open looknlisten, you might just get to see the otter at the bridge. Thanks for the post and we look forward to your next one.