Turns out the Water Vole(s) was/were, and I quote: "... the first confirmed sighting [on the reserve]..."
BOOM! RATTY BOOM! RATTATATATTY-BOOM! RATATTY-RATATTY-RATATTY BOOM!
One's mammal patch list leaps to about 24 (if we include Feral cat, Pipistrelle sp. and a dead dolphin sp.). I should probably invest in a bat box and mop up a few wingèd insect munchers, beyond that maybe a wandering Wild boar? Or a Killer Whale off the point?