Ostracods

Ponds throughout the country are starting to fill up with frogspawn, but not in the new one in the garden.  However, another creature does seem to be thriving:

About 2mm in size, a highly magnified picture (done via photo editing software) shows they look like very small baked beans.

Thanks to the Wild About Britain forum they have been identified as a ostracods, a small crustacean, of which there are an estimated 10,000 different species.

The defining feature of ostracods is the shell that covers most of the creatures body, form which limbs protude.  A quick internet search shows ostracods are a very popular area of research - different species can be herbivores, parasitic and predators.  Predatory ostracods can attack in groups, eating their prey alive. 

But the ones in pond seem to be congregating by some algae, so it is a reasonable assumption that the pond snails are safe. 

As it is a new pond, it is most likely they arrived on the legs on one of the several birds that drink and bathe in the pond.

Perhaps it's time to invest in a microscope.....

Little Brown Job

The bird feeders in the garden usually attract sparrows, goldfinches and the occasional greenfinch.  But this morning there was something new:

I not a birder but it does seem like a female reed bunting - any ornithologists reading please correct me.

Insects

The warmer spring weather over the past couple of weeks has bought out the hibernating insects. This coma butterfly, sunning itself by the Thames last week:
  

  
This ladybird was moving around in the garden
   

   
Although this buff tailed bumblebee had not fared to well, movingly slow and probably dieing along the ock valley walk
   

   
But it did seem grateful to be moved to a nearby flower:
  

Mink by the Thames

Continuing the theme of poor quality photography, I caught a glimpse of a mink along the river Thames last week.

Although water voles have over 25 predators - including heron, birds of prey, cats and rats - it is mink that is often cited as one of the main causes of the decline in water voles.  A restrospective study by Stachan & Jefferies (1993) concluded that although they have  declined throughout the 20th century, it is during the 1980's that it accelerated which correlated with the rise in American mink that escaped or were released from fur farms.  Fur Farming was eventually banned in the UK in 2000. A great deal of other research has been conducted into the affects of mink on water vole and other wildlife and it matches matches my own experience. 

In 2005, there was a strong water vole colony near the Thames, where I could see a water vole on most visits.  But I never saw any during 2008 and only one in 2009, as shown in the 2009 water vole map:

View Water Voles in the River Ock - Abingdon, 2009 in a larger map

The 2010 map  has been updated with a red pin - to show the location of the mink.

View Water voles 2010 in a larger map

As can be seen, the mink is in the area of this colony and is probably the best explanation for the colony's decline. 

The Thames Valley Environment Record Centre, BBOWT and other interested parties have been informed.  

This particular sighting was on the over side of Abingdon, so the colony along the river ock is not likely to be affected by it.

First water vole of 2010

Now the evenings are getting lighter evening walks along the river are now possible and despite the fading light I have been treated to my first water vole sightings of the year - even if the photographs are of very poor quality.

Maybe with good weather at the weekend I may get a chance of something better, but at least the water vole map of 2010 is started with it's first two pins.

View Water voles 2010 in a larger map

This is the main colony along the river and is where I saw a majority of my sightings last year, so it's probably not suprising to see water voles along there.  But it's still very pleasing to see they survived the very cold weather and high water during the winter.

For considerably better water vole pictures I refer you to Terry Whittaker's excellent photographs:

http://terrywhittakerphoto.blogspot.com/2010/03/our-friends-in-north.html

Water vole burrows

Saturdays walk also showed several water vole burrows along the river bank.  These could be abandoned ones that I saw last year

Maybe I'm being optimistic, but are a few of them are showing signs of recent activity? With freshly dug soil below some of the burrows

And is that footprints I see?

With the days getting longer and warmer hopefully it won't be long till I find out....

Saturday morning walk

Now the cold (both weather and illness) seem to have subsided it's good to get back out for the weekend morning walks. The bird orchestra in the hedges now include blackbirds

They have also been joined by great tits,  to me they sound more like squeaky gate birds than song birds, but are still are a welcome sight out sound

Over a month ago I saw a great crested grebe on the river and said confidently "I imagine if I go back tomorrow it may not be there".  

Well it's still there and a I spent several enjoyable minutes watching it fishing, diving under water and reappearing further along the river.  

Which just goes to show I know nothing.


Though things should get easier now the great source of reference that is the 'Collins Bird Guide' is now available on-line with a rather splendid web site: http://www.collinsbirds.com/

Moles

It is easy to get carried away looking for water voles, badgers and now otters and miss the commonest of mammals, especially those which are quite literally under our feet.  But evidence of moles, in the form of mole hills are all over the place, including the verge along Mill Road.

Ironically, as moles they spend virtually their whole lives underground, I am probably more likely to see an otter than a mole.