Fossorial Voles II

On the Wednesday night of Site A trapping I received a message from Robyn saying that she had arrived to check the traps and found many of the metal Shermans stolen and others thrown around the site. Luckily we had previously clipped open the tube traps and left the Shermans unset so that there would have been no animals inside when this act of vandalism occurred. This is one of the many risks when conducting fieldwork in an urban area, some people do not have any respect for the work that is being done, or for some reason have an issue with the water voles in the area (who know why anyone wouldn't mind these lovely creatures in their neighborhood!). Signs were posted at the site explaining what was going on but a lot of the time we arrived to find them stolen or kicked over by kids. On the other hand if you do not post signs and inform the public, they may happen across the traps by accident and assume that something untoward was going on and interfere anyway.

Burrow with feeding signs at entrance

The reason for not setting the traps the night before was because trapping was a bit too successful! At the previous night check every trap had an animal and Robyn was understandably a bit overwhelmed - every animal has to be measured, weighed and microchipped with all the details taken down, no easy task when dog walkers are coming up to see what you are doing!

The second week the traps were moved to Site B, a different habitat, this time more of a sloping bank like you would expect of the voles but still nowhere near water. The bank is artificial disturbed soil, colonised by a variety of grasses such as Yorkshire Fog, Cocksfoot, Bent Grass and Holcus mollis. The site is opposite a row of houses with an area of grass in front that is cut by the council, dogs are walked there but it is generally a lot quieter than Site A. Perhaps surprisingly the population of water voles there seems to be a lot lower, this may be because of fox predation, where the foxes are not deterred by the amount of dogs and people passing through. Despite lower trapping numbers we managed to capture a couple of juveniles including this guy:

Black Juvenile Water Vole

Me preparing our youngster for body measurements

We also landed a large breeding female, who was probably the mum of one of these kids! I had the fantastic opportunity to handle a few animals, with proper precautions I add as these guys can be fiesty and give a hard bite if you are not careful. When I first read up about water voles I thought that the English population were brown in colour and the Scottish black coated, however during this week I found that there were some lovely brindle and brown coated animals here too.

One of the mums

The field signs were a lot harder to see compared with Site A, the runs were less visible and you had to lift up the tussocks of grass to see many of the tunnels and tumuli (mounds of earth dug out of burrows). Where at Site A there were latrines clearly visible at almost circular points around the periphery of the burrows, you would struggle to find one or two at Site B. The spread of the burrows and territories also seems to differ in that they are strung in a horizontal line, following the ridge of the earth.

There were also signs to be found under discarded wood and a mattress amongst the grass...

 

What's under the board?

I'm off on holiday for 3 weeks around Vancouver Island in Canada, hopefully when I return I'll have few photos of fauna to share!