Surveying for signs of otters
I recently spent an afternoon at the RSPB’s Ottmore Reserve in Oxfordshire learning all about otter ecology and surveying - including getting very up close and personal with samples of otter spraint!
Led by Ellen Lee of Thames Valley Environmental Records Centre it was a brilliant introduction to the habitat, distribution, behaviour and ecology of these amazing creatures. Fortunately, after several decades under threat, they now appear to be flourishing.
These are the new things that I learned about otters:
In England, Male’s tend to live along larger rivers and females in streams and reed beds (seems this is because it’s easier to bring up young in more sheltered and protected locations like this).
Dog otters are generally solitary, very territorial and take no part in the care of the young.
Otters don’t tolerate disturbance well - hence they tend to be nocturnal in England and Wales. Fewer people in Scotland means they are out and about a bit more especially on the coasts.
80% of their diet is fish - and crayfish are a popular snack which we know from the signs left behind in otter spraint (poo)! Crayfish legs and body parts can often be seen.
They mark their territories by depositing spraints (droppings) on prominent places (bridges, rocks and boulders, concrete plinths, river islands) - this seems to simply to a way of saying I have been here and caught my lunch so don’t bother trying! A resource management strategy.
If you see a bare earth slide on a river bank it is more than likely signs of an otter - as well as ‘runs’ through reed beds.
Their spraint has a distinctive fishy smell and even a hint of jasmine. Its not unpleasant to sniff unlike mink which is very, very stinky (you have been warned).
Wandering around Ottmore in the afternoon, we saw various signs that there was an otter about (mostly old spraints left at strategic points). Some of it we took back, cleaned using sterilising fluid, and peaked at through a microscope. From the looks of some of the fish scales, Perch had recently been on the menu.
The following day I wandered down the banks of the Thames not far from where I live and found some spraint of my own - even if rather old. The willow it was resting on was a perfect otter snack spot - horizontal branches hanging low over the water from a river bank. It’s thrilling that there is an otter living so close to where I do.
Ellen was quite right - if you want to spot signs of an otter you have to think like an otter. Now I’m hooked on surveying for them to see if there are more around in this part of the world. Much more up my street that playing Pokemon Go!