Where are the water voles?

Normally, along the river there would be lots of signs of water vole activity and they would be fairly easy to see as they define breeding territories.
But the cold spring seems to have delayed the start of the water vole season, but there a few signs of increased activity, including the distinctive evidence of feeding:
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And the first water vole latrines are starting to appear:
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Although the most obvious sign is the ever increasing number of new burrows:
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But it's not all good news, opposite these burrows is a fairly fresh mink scat.
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Yet further downstrain, there is evidence of a different mammal activity - a dry spraint, indicating there is still otter activity of the river.

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Meanwhile over at the 'About a Brook; blog, Kate is seeing a lot more water vole activity and close encounters with a different mustelid: http://staggsbrook.blogspot.co.uk/