Wednesday 27 July 2011

Family group

Young bat my neighbours found (unharmed) in their curtains. Released the same evening. Pipistrelle?

Peripheral adult.

Young water vole (above and below).


Mum - the same adult vole I saw last night, I think, because of band of dark fur above the eyes.

Mum again.

Mum and youngster - no fighting at all!
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I was privileged tonight to watch what I assume must have been a family group: at least two, possibly three young of exactly the same size sharing a piece of apple and swimming up and down the same stretch, plus an adult who seemed to be wholly tolerant of their presence in a way that suggests a parent and offspring. I saw this same adult vole top up the latrine too, so I'm guessing a female. In other words, mum and babies. There was at least one more adult lurking on the fringes.
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Delighted to report too that we have a hedgehog in our garden.

Monday 25 July 2011

Grocontinental: after the diesel

Edgeley Road water vole. If you click to enlarge, you can just make out the orangeness of the teeth.

By the short culvert in the middle of the field. Just a few droppings is all it takes to confirm water vole presence.

Old latrine

Fresh latrine

Vole-cut stems.


Skull found at the Edgeley road end. Normally water vole teeth are much yellower/orange than this - I think this orange colour of the enamel is to do with extra strength as w-vs use their teeth to dig. I can't account for the paleness of this particular vole's enamel, but the size shows it definitely is water- and not field- or bank-vole.

I'd intended to survey the whole length of the stream as it goes past the Waymills units, but I was only able to get half way up the first field because the nettles and thistles are now chest-height and I ran out of steam. What I did find, though, was encouraging.
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A week or so after the discharge of diesel into this brook, the voles seemed to vacate that stretch. Where there'd been abundant signs before, suddenly there was nothing except right at the Edgeley Road end just before the culvert. However, a few months down the line and activity seems to be spreading slowly back up again.

Sunday 24 July 2011

When colonies crash

Young Edgeley Road vole swims past, spots me...

...and dives.

I've not been able to get down to the Prees Branch Canal reserve much this year, but when I did make it a couple of weeks ago I was dismayed to find no real evidence of water voles at all. This had been a strong colony for years, despite some mink scares along the way. But when the rest of the Whitchurch Water Vole Group went down to check, they were able to find only scant signs of a much-reduced population.

It does happen. White Lion Meadow was stuffed with water voles in 2006, and yet now the numbers are much reduced. The voles who live under the railway bridge at Homebase disappeared over the summer a couple of years ago, but came back the following spring and we never knew why. And of course last July the Greenfields/ Whitchurch County Park site was cleared out by mink, only this year it's recovered well and there seem to be more voles down there than ever.
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Water vole colonies are fragile and need monitoring and occasional intervention (eg reporting pollution to the Environment Agency). If the problem is resolved and there are water voles living nearby, vacated areas can fill up again fairly quickly.

We don't know what's caused the crash at the Prees Branch Canal - my guess is mink - but I do hope next year there's better news.

Wednesday 20 July 2011

More about poo





I know these droppings are water vole because I saw the vole responsible, but it's unusual in my experience to see such a very light green colour. That's the kind of green I usually associate with field vole.
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These voles sitting next to each other are probably from the same family group (otherwise they'd be fighting). It could be parent and offspring. Note the fuzzier fur of the juvenile.

Saturday 16 July 2011

Rat Reprise


I've covered this subject before but it bears repeating: water voles are not rats. The chap in the photo immediately above is a common rat, Rattus norvegicus, with grey fur, prominent ears, a pointed pink nose, white feet and (if you could see it) a naked grey/pink tail.
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Our water vole, top photo, has brown fur, tiny ears set close to the head, a blunt black nose, black feet and a dark furred tail.
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If you need to get rid of rats in a water voley area, you need to seek professional advice as it's an offence to harm water voles even accidentally during genuine pest control.

Wednesday 13 July 2011

Joy!


Great news: I popped down to White Lion Meadow on a whim really, and slid down the only bit of bank you can now access as that stretch is now so overgrown. Straight away I found this latrine on top of an old car sponge. As I said in the post below, it's great because this is definitive proof that you've got breeding water voles there.

I should mention, a survey by professional ecological consultants this spring stated that "no water voles, or evidence for the presence of water voles in the form of latrines, burrows or feeding remains were recorded." (The whole report is on the Shropshire Council planning website here: http://planningpa.shropshire.gov.uk/online-applications/files/BC3F6F47A70200A7B0416BCDE9AC7F19/pdf/11_01988_FUL-ECOLOGICAL_ASSESSMENT-1442949.pdf

Yet this blog has photographs of voles at the site actually in April, the same month the survey took place, and now this latrine verifies at least one breeding female.

A couple of observations on latrines



Degraded latrines can be hard to see.

Unusually long water vole droppings. Generally they're shorter than this, more Tic-tac-shaped.

Definitely too chunky for field vole feeding!


Arguably latrines are the most important field sign of all. Not only are water vole droppings the most unambiguous sign of w-v presence - given that small feeding stations can be confused with those of field voles; burrows and footprints can be rats'; even sightings of the animals themselves aren't always clear as rats and f-vs swim about in a similar way to w-vs - but also the theory is that latrines can be used to estimate populations. This is because the female voles use them as territorial markers during the breeding season.

A formula has been developed which allows the number of water voles to be estimated from the number of latrines found: y = 1.48 + 0.683x where x = latrines counted and y = water voles (Morris et al., 1998).

However, when you're doing surveys it's easy to miss latrines because droppings are often mud-coloured (though they can also be dark greenish or almost black). In addition, they'll probably have been at least partly trampled flat by the female to spread the scent around - kind of like drawing an emphatic border round your 'Trespassers will be prosecuted' notice. So you need to really part the grass and get right down to earth level. Look for even slight discolourations to the soil, as in picture 3, and use camera zoom or binoculars to study likely-looking but inaccessible patches of bank. Water voles often like to use a raised or prominent area for a latrine, so a little spur of earth jutting out into the stream is a good place to look, or some protruding rubbish (polystyrene tiles and broken-off fence posts dropped into the water seem popular). I've even seen them on mole hills.

And remember that the calculation is only as good as the number of latrines you actually uncover. It may be you've missed half, or even more.

Tuesday 5 July 2011

Not much bigger than an apple core

Baby water voles are weaned at 14 days.

A slightly older but still not fully grown vole.

The plank I put down is now being heavily used as a latrine.

This very small vole at the top must be pretty new out of the nest because its body's only slightly longer than the apple core it's travelling past - about 3-3 1/2 inches. But the young vole was swimming confidently on its own, and certainly knew how to duck out of sight beneath the grassy overhang.

Sunday 3 July 2011

Silver Studded Blues




I've fallen a bit in love with these rare butterflies, found on Prees Heath. They're smaller than Common Blues, and have a distinctive underwing pattern that features a little blue 'stud' in the centre of one of the ring markings round the edge of the wing (see post below for a photo of this). I'm guessing that the brown specimens are female and the blue male - not sure about the one that seems to be both!

Saturday 2 July 2011

Four Voles Tonight



Spot the latrine!

In the happy position this evening of not knowing where to point my camera because the voles were so active.

Friday 1 July 2011

Greenfields and the Country Park again

Silver Studded Blue I found on Prees Heath last night.

Otter spraint.

Water vole prints from Greenfields reserve

Juvenile vole. I also had sightings of an adult and a baby this evening.

Normally I'm scrupulous about taking home any uneaten apple, but tonight I chickened out.

Good results from a survey this Thursday on Greenfields Nature Reserve and the area immediately around it, Whitchurch Country Park. There were lots of water vole feeding stations and latrines all along the back of Brookfields and on either side of the bridge at Greenfields Rise. When I checked under the other bridge, the one inside the reserve, there were water vole prints in exactly the place I'd seen a vole running when I was with my son a couple of weeks ago. There was also fresh otter spraint. Encouraging, as long as this year we can keep the mink at bay.