Baby water vole

Four water voles yesterday evening, including this one - first time I've seen a baby water vole....
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River flora

Along side the river, the meadows are turning to seed, but in the river itself the plants are just starting to come into life:
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Unfortunately that includes Himalayan Balsam, once again it is growing in swathes along the river bank.  Despite valiant attempts to clear it, the river banks are too steep to get it all. Although it is popular with the bees that have lost the meadow flowers it is unfortunately it is taking over where native vegetation should be growing.
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In the river itself, the arrow head is once again starting grow, something which is fairly abundant on the ock, but according to my recently purchased 'Collins complete guide to British Wild Flowers' is 'locally common in the south, but scarce elsewhere', so perhaps I should treat it with more respect.
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The water crowfoot is starting to bloom, apparently there are 7 different types of crowfoot - a member of the buttercup family and I'm guessing this is river water-crowfoot (as opposed to stream water-crowfoot which is rarer, but has a very similar description):
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Perhaps most interesting is the 'flowering rush', a plant that is on the Oxfordshire endangered plant list - thanks to David for telling me about it.   Described as 'locally common' this is the only one I've seen, despite walking past it several times and never noticed. It's also hard to get a photograph of:
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Of course, with the exception of the himalayan balsam, this flora is good for the fauna that lives on the river:....

Murder mystery on the Ock...

The river Ock, like most of the rivers of England, have been invaded by Signal Crayfish and last year I found a dead one along the river bank:
http://viewsoftheock.blogspot.com/2009/06/ock-valley-walk.html

Whilst surveying for water voles on the upper Ock I encountered another one near Drayton Road Bridge, but this one has suffered a more violent fate - ripped in half and partially eaten:
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When I returned the following day, the carcass had completely gone.
So far, Wild About Britain and Twitter have drawn blanks, so I am left to carry on the tradition of Oxfordshire detecives and investigate who the culprit might be.  I have several suspects to chose from:


People: At the time I suspected the first corpse was a victim of a fishing incident. Discarded when caught by accident.  But  it is unlikely to have been caught by a fisherman as the bank at this part of the river is steep and the undergrowth is high and restrictive.
Also, catching crayfish is illegal without a permit from the environment agency - as it is known for animals (including otters) to be killed in crayfish cages and why would anyone leave a partially eaten crayfish corpse by the river?
Therefore, I suspect the crayfish was not killed by a person.


Rats: I have seen rats further downstream and there are  almost certainly several in the area.  However  I have not found any evidence of a rat killing a crayfish, but it is not outside the realm of possibility.
Although I suspect a rat would go for an easier target - a moorhen chick or a discarded take-away.


Mink: It is highly likely that a Mink would kill a Crayfish in this manner, given they will attack and kill most creatures they encounter.  But there is no evidence to support the idea of mink on the upper Ock: there are no obvious scats; there are water voles and young moorhens nearby - often the first victims when a mink moves into an area. 


Birds: Several birds are known to catch and kill crayfish - Herons (who would swallow it whole), Owls & Buzzards - but a heron would swallow it whole, whilst the others would eat it on a perch away from the river.


Otter: There are cases of otters killing and eating crayfish and there has definitely been at least one otter on the river, as I found an otter spraint  back in February


http://viewsoftheock.blogspot.com/2010/02/in-search-of-otters.html


But the spraint was found over a mile stream upstream where the river is deeper (and before it splits into the upper and lower ocks) and here the river is flowing under the bridge before it becomes it flows through the ock valley walk - popular with dog walkers and children, something an otter would have previously shied away from. Although otters are now being recorded in urban areas - Reading, Leicester & Birmingham - it is possible that they have ventured this far downstream.


Like the best murder mysteries each of the suspects have their albies, but base purely on circumstantial evidence my chief suspect would be an otter.  Hopefully the planned use of mink rafts later in the year should give further evidence of mustelid activity.


I welcome any readers have any insights or suggestions into the death of the crayfish 

Botanical Bling

Just outside of Abingdon are the Cothill Fens - a collection of nature reserves where the springs form a series of fens which drain into the Ock via Sandford Brook.
At this time of year, the orchids are in full bloom and people come from far afield to see them, including marsh helleborine:
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And the common spotted orchid:
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It will be interesting to see how the planned grazing at the Dry Sandford Pit reserve (due next spring) will affect the number orchids in the fen and whether the orchid spotters will be disappointed.
Other plants are just attractive.  Including common bird's foot-trefoil, easy to miss in the lichen heath - an area heavily grazed by rabbits:
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Although common knapweed can look as impressive as any orchid and is a magnet for many insects like this buff tailed bumblebee.
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Moths, butterflies & other insects

The warm weather has provided an ideal opportunity to seek out some of the insects that inhabit the ock and the flood meadows - some seem almost exotic.

Male banded demoiselles along the river, possibly competing with each for the best spot to attract a female:
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A rather splendid scarlet tiger moth, a locally common to the south of England. A moth that prefers damp habitats and flies during the day.
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Also locally common is the marbled white butterfly, apparently it favours flower rich meadows, hence several seen flying around the ock meadows:
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Although no sightings of a leaf cutter bee, one has left evidence in the form of these distinct cuttings in a leaf:
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