Tag Archives: Wood Mouse

Vole Patrol reprise: visiting nest boxes

Huma and John on Vole Patrol with Mammal Nest Box Perivale Wood
Huma and John on Vole Patrol with Mammal Nest Box in Perivale Wood

We revisited the nest tubes and nest boxes that we put up for small mammals in four of the Vole Patrol study woods a few months ago. It seems another world: bare leafless trees over chilly wet forest floor have been replaced by a thick green mantle over a mass of brambles that seem to have shot up faster than tropical bamboos and bananas (my father maintained that he could watch a banana leaf unfurling while he shaved in the hospital he was running in postwar Malaya, but I digress).

So it was a case of first case your hare, or rather, first find your small mammal box.  Gunnersbury Triangle’s densest parts are pretty thick, and the nest tubes had been put up somewhat at random as the new team did its enthusiastic best on its first day of training all those months ago, followed by the brambles doing their enthusiastic best to hide all traces. We did well to locate 14 of 18 nest tubes: none of them seemed to have been used. We moved on to Perivale Wood, where stout wooden boxes like bird nestboxes had been tied to trees in a much more regular array, and we found them without too much difficulty.

Mammal nest box used by Wood Mice, with opened hazelnuts
Mammal nest box used by Wood Mice, with opened hazelnuts

Three of the Perivale boxes were inhabited by Blue Tits, the helpless youngsters lying inside while (we suddenly realized) the alarmed but brave parents chattered excitedly outside. We closed the lids and backed off as quickly as we could. The boxes have the openings on the back to encourage mammals and discourage birds, but it’s of only limited value against sharp-sighted Blue Tits. One of the boxes had certainly been used by mammals: two hazelnuts had been opened by small teeth, their ends neatly gnawed to circular holes. I’m not certain I understand how a nut can be withdrawn through such a little hole.

Off to Tentelow wood through the grinding traffic. A game of cricket was going on in the playing fields; it was hot in the sun, a lot cooler under the canopy. The nettles were waist high, the brambles thick. It seemed impossible we would find any of the nest tubes, but we did, eventually. A Scorpion Fly perched on a bramble leaf beside the path.

Sir Thomas Gresham's symbol, a golden grasshopper (a pun on his name, Grass-Ham), at his building in Lombard Street
Sir Thomas Gresham’s symbol, a golden grasshopper (a pun on his name, Grass-Ham), at his building in Lombard Street (photo: Wikimedia Commons)

Then we drove down to Long Wood, part of Sir Thomas Gresham‘s Osterley Park estate. He liked insects enough to use a golden grasshopper as his symbol, punning on his name, which might be Grass-Ham, village in the grass. It’s a beautiful wood, coppice with fine tall straight Oak standards, a proper stream running clean through a steep-sided valley, sullied only by the continuous roar of the M4 invisible above. Chiffchaffs and Blackcaps sang above the din.

Brown Silver-line Moth Petrophora chlorosata at Long Wood
Brown Silver-line Moth Petrophora chlorosata at Long Wood, Osterley

I disturbed a Brown Silver-line Moth, which flitted among the nettles and bracken. We saw Holly Blue, Speckled Wood, Large White, and Red Admiral butterflies: it looks a fine place for Purple Hairstreak too.

Acorn Weevil
Acorn Weevil, Curculio glandium

When I got home, I found this funky weevil under my shirt. It looks very much like the Acorn Weevil, presumably from one of the many Oaks I walked under.

Wraysbury in the Mist, and Leafy Lichens

Willow Reflections in the Mist
Willow Reflections in the Mist

Well, after 7 Vole Patrol postings, and some very cold, wet and early mornings, I felt like enjoying a nature walk in the sunshine, away from Woodmice. But as I left town I found myself in fog, not too thick to be sure, but fog nonetheless.

I was rewarded, however, with the lovely sight of the willows along the lake seeming to float, isolated in the smooth sea of soft gray.

As the mist slowly lifted, a pair of Goosanders and a pair of Goldeneye (the male displaying, the female in tow a yard behind) could be seen through the mirk.

I couldn’t get away from the mammals, either. I was pleased to see not just the usual Muntjac prints along the path, but Roe Deer too.  A little way further, and there was a Wood Mouse hopping in a relaxed way across the path, before diving down its hole.

Woodmouse hole
It went thattaway: Wood Mouse hole

Among the birds calling were Green Woodpecker (finely), Great Tit, Song Thrush, Cetti’s Warbler. A Heron and a Parakeet flew overhead. Wood Pigeons and Carrion Crows watched warily.

The damp air had another good effect: the lichens looked wonderful, and even the bristly Ramalina were soft.

Parmelia caperata
Parmelia caperata
Ramalina colony
Ramalina colony, generally hard, and the same both sides
Evernia prunastri colony, always soft, and white below
Evernia prunastri colony, always soft, and different below

It was nice to see the lichens flourishing so close to London (and Heathrow): these little fungus/alga plants are very sensitive to pollution, and when I was a boy they were almost impossible to find anywhere near a city, so conservation stories can be happy.

Vole Patrol 7: Massive Morning Catch!

Vole Patrol coding measuring recording
Vole Patrol  hard at work! Coding (clipping fur patches), measuring, recording

I’m so cold! My feet are frozen! said Huma. It was indeed a chilly bright winter’s morning. We were grateful when the sun came up and warmed the glade where Vole Patrol had set up its measuring station, with tarpaulin, big sacks for opening traps, small bags for weighing and measuring, all the traps in order, scissors to code the animals’ backs, rulers, scales, fresh hay and three types of bait.

Mouse from M3 - hold still now
Mouse from M3 – hold still now

Unlike the meagre daytime catch of yesterday afternoon, 20 of the traps contained mice.

I had a go at measuring and coding; then Huma put a mouse back in the big sack, as if just out of an opened trap, and under her watchful eye I caught it gently by its scruff, transferred it to a small bag, and weighed it. I’m a mammal wrangler! The main difficulty, apart from their remarkable ability to escape, is that they hunch up, making straight-line measurements rather tricky.

Mouse from M2
Mouse from M2 – a female

Only one other trap had been triggered, so the false alarm rate was well down now: resetting the sensitivity of all the traps had been more than justified.

Wood Mice have big round ears
Wood Mice have big round ears

We were soon very busy: bringing in the full traps; opening them, catching the mice, coding their back fur, measuring, weighing, carrying them back to where they came from and releasing them.

Measuring and recording the weight
Measuring and recording the weight

Tony the ecologist, who helped with the trapping today, said he’d expected Wood Mice rather than voles. Voles cannot easily make their way along railway embankments as they’re predated by Foxes and Badgers, which freely use railway  “corridors”. Small isolated populations can easily die out, which is probably what happened here.

Vole Patrol 6: First Catch

Woodmouse in hand
Wood Mouse in hand

We approached the now armed and possibly triggered traps with some excitement. Of the six traps in “our” row C, four had been triggered. We picked them up, locked the other two so we wouldn’t catch any more mice while we were analysing the catch, and brought the four traps to Huma.

She opened trap C6 inside a large bag. A Wood Mouse shot out into the bag. I got a very blurry picture of a shadow behind the plastic.

Opening the first trap C6
Opening the first trap C6

Huma reached for the Wood Mouse. It bounced speedily up her arm, through the gap at the top of the bag, and hopped away over the tarpaulin. None of our other traps had anything in them. I must have looked disappointed as Huma told me there would be more.

Luckily there was: one of the meadow traps had caught a fine large male Wood Mouse.

It's a Boy
It’s a Boy
Wood Mouse has a yellow patch on chest
Wood Mouse has a yellow patch on chest

We sexed, coded (A = clipped patch on left shoulder), measured body length and hind foot, and weighed the mouse. It wriggled quite hard and almost escaped, but Huma was quicker.

Mouse A's fur is clipped on left shoulder
Mouse A’s fur is clipped on left shoulder
Measuring the hind foot
Measuring the hind foot
Weighing
Weighing

Then we took the mouse, still in its bag, back where it came from and let it go. Likely it will feast on the plentiful bait in the warm dry trap again.

Out of 32 traps, 8 had triggered and 2 had mice in them, much too high a false alarm rate, so Huma reset their sensitivity for tomorrow morning.