Winter Migrants

As autumn slowly turns to winter, there is very little to see on the Ock - most of the surviving water voles (if any) now spend most of their time in their borrows, the adult insects have died and leaving their young to overwinter as eggs, nymphs or lava and the summer migrants - (warblers, swallows and hobbies) have returned to Africa.
Whilst a few winter migrants like redwings will hang around the hedges near the Ock a better place them is Otmoor.
Frequently featured in this blog, Otmoor is an expanse of meadows and wetlands just north of Oxford:
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It is here that dozens of lapwing come to spend the winter:.
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But the real stars are the starlings, with winter migrants from northern Europe and as far away  boosting their numbers to tens of thousands, making their flocks just before dusk one of the season spectacles in Oxfordshire.
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Water voles 2013

A recent report by the Environment Agency and the Wildlife Trusts have indicated that the UK water vole population has decline by 20% this year:  http://www.bbc.co.uk/news/science-environment-23975749

It certain matches what has been happening on the Ock, having done six water vole surveys this year (three on the Ock in Abingdon and three on Nor Brook to the west of Marcham Mill) there have been no positive signs of water voles -  latrines or sightings.

Also, with regular trips down to the river there have been significantly fewer sightings in 2013 when compared to previous years - as illustrated in the chart below.

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When in 2011 & 2012 there were multiple sightings during 2011 & 2012, I have only had 5 sightings this year and most of those were on the Lower Ock, such as this one taken back in April:
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There are several possible explanations for this:

• Small mammal populations fluctuate and this could just be part of the natural population cycle (and 2011 could have been a population boom).
• The bad winter and the poor spring could have hindered the breeding season, possibly unlikely as other water vole populations in the area are doing very well.
• Despite control up stream a breeding population of mink could have established itself along the Ock.
• Or just plain bad luck, maybe the population of the Ock has not changed, but I have just been unfortunate with sightings this year (and this is far from a scientific study).

It is difficult to draw any conclusion from just one year, but as water voles (like most small mammals) are prolific breeders hopefully the population will re-establish itself next year.
If not, then there could be something seriously wrong with the river, especially as Abingdon and the Ock are important locations for an animal which has had a torrid time in recent years.

UK Fungus Day

Sunday (13th October) was the first UK Fungus Day.  An idea by British Mycological Society and other groups,  the idea being to raise the profile of fungal related research in the UK and to highlight the importance of fungi within the UK environment.

Unfortunately, Sunday was too wet to get out and investigate the local fungus, however the excellent (so far) autumn has given the opportunity to explore two of UK's most important and interesting fungal sites:

Previously mentioned in this blog, Burnham Beeches is a 500 acre beech woodland just north of Slough and the quantity and rarity of it's fungus has made it an Special Area of Conservation and a National Nature Reserve.

There are over 250 different species of fungus found at the beeches including:

The pale oyster mushroom - Pleurotus ostreatus:

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The Bitter Beech Bolete – Boletus calopus:

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The elegant Porcelain Fungus - Oudemansiella mucida
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And the very impressive Giant Polypore – Merupilus giganteus  

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The New Forest has a staggering 2,500 different species of fungi and within a few square metres there is an impressive variety, including what is probably the most easy to identify UK fungus, the Fly Agaric (Amanita muscaria):

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However, the less distinctively coloured fungus are a lot harder to identify - this could be a Grey Spotted Amanita (Aminita excelasa):
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Whilst this one might also be another Grey Spotted Amanita, a Blusher (Amanita rubescens) or perhaps a faded Fly Algaric.

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Now foraging has become evermore popular, large scale harvesting fungus has become a real problem, the Corporation of London (the authority who manage Burnham Beeches) has a complete non-fungus picking policy:
http://www.cityoflondon.gov.uk/things-to-do/green-spaces/burnham-beeches-and-stoke-common/Documents/Burnham-beeches-fungi-policy.pdf

Whilst the Forestry Commission (who manage the New Forest) permit collecting of up to 1.5Kg of fungus, commercial harvesting is not permitted and in several locations it is banned altogether:
http://www.forestry.gov.uk/forestry/infd-6e3gaz

In order to comply with the by-laws and not wishing to disturb the fruiting bodies, none has been picked  and all identification has been done via photography and  using the field guides: Roger Phillips Mushrooms & Collins Complete Guide to British Mushrooms and Toadstools 
As identifying fungus is hard, these identifications maybe incorrect - so comments and corrections are always welcome.

Poor quality fox photographs

Back in July the meadows alongside the Ock were cut andany small mammals that were hiding in the long grass may have met with an unfortunate demise.
However, what may be bad luck for one may good fortune for another, such as this young fox, searching for remains amongst the cut grass.
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These photos were taken back in July (the memory card got lost till now)

Meanwhile at Radley Brook..

Any regular readers will know that the Ock water voles are not the only ones to feature in this blog, there is another population at Radley Brook in North East Abingdon:
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It is a small ditch and suffers the same problems as the Ock - frequent flooding and possible predation by mink, but being only a few metres from the Thames these are even more likely.
But despite this there is a stable water vole population, which can be very hard to see due to the amount of Sedge:
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But with a lot of patience over many days it is possible to catch a glimpse of one of them, as they lurk amongst the sedge.
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No water voles?

Up in Shropshire, Kate seems to be seeing a water vole boom - where the voles have become so brave she is even feeding them by hand (as well as getting some great photographs):

http://staggsbrook.blogspot.co.uk/2013/08/when-voles-grow-bold.html

However, along the Ock, it is a more solemn story, where last year there were water voles feeding on the arrow heads, this year they remain untouched:
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This has lack of grazing has allowed some of the river plants to flower, including this flowering rush:
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When there is an obvious decline in a water vole population the first suspect is the presence of american mink.
However, there are several young moorhen of different ages (more than last year), which are often a favourite of mink:
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So maybe the reason is more complex - perhaps this years wet winter followed by a very wet spring combined with a natural low breeding cycle has resulted in a lower population.
However, along the Lower Ock, there are signs of water vole activity, a latrine:
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As there is over 20 miles of water vole habitat along the Ock and its tributaries and as water voles are fast breeders it is very likely that the water vole population will once again increase in subsequent years.
That is of course assuming that reason for the decline is not the presence of mink....

The rarest creature in Oxfordshire?

When thinking of what might be rarest creature in Oxfordshire it's easy to think of the large mammals which get a lot of media interest - the otter, once extinct from virtually all of England or the water vole - the fastest declining mammal in England and still missing from a lot of it's previous sites.
But probably the rarest animal is a creature that we wouldn't recognise even if we did actually get to see it and a contender is an insect found only in a couple of very small streams within the Cothill Fens - a series of nature reserves outside of Abingdon that feed Sandford Brook - a tributary of the Ock:
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From a distance, it looks like any of the small blue damselflies that are found around rivers and ponds at this time of year.
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And it requires a closer inspection to reveal the markings of the Southern Damslefly:

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What distinguishes it from the other small blue damselflies is the markings on the top of the abdomen.

An insect so rare that is only found in a very few sites -  shallow base-rich streams within an acidic heathland - and the UK population is estimated to be a quarter of  global population.
Yet the Oxfordshire population is so small and fragile that it doesn't even get mentioned in some field  guides.

It's scarcity lead it to be one of the insects that feature in a series of stamps released in 2008 to highlight the plight faced by many UK insects.

http://www.norphil.co.uk/2008/04b-endangered_insects.htm


References:

http://jncc.defra.gov.uk/protectedsites/sacselection/species.asp?FeatureIntCode=S1044
http://www.british-dragonflies.org.uk/species/southern-damselfly
Dragonflies & Damselflies of Great Britain & Ireland - Brooks & Lewington

Sunday Butterflies

With the wet spring it seemed like it would be a difficult year for butterflies, but now the hot summer has started (even if there have been a few torrential showers) the local butterflies have started to appear:

A Large White:

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A meadow brown:

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A peacock, less distinct with it's wings closed.
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A red admiral
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And a small white:
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Return to the Ock

Anyone who has heard one of my talks this year will know that the summer is not one of my favourite seasons for walking along the Ock - it's often hot, there are squadrons of small biting insects and the with the foliage so high it's very difficult to see what is happening on the river:

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Where it is possible to see into the river, a family of swans have moved in:

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Making the most of the recent warm weather and the abundance of small insects, the damselflies are emerging, such as this splendid banded demoiselle

 Although harder to see than in earlier in the year, the water voles are still present, such as this one lurking inside it's burrow:
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Views of the porch...

Sometime during the 1980's my sister visited a school fate and returned with a small cactus, it lived in the recently built greenhouse where it prospered so well it started to produce offshoots - which we cut off and replanted (our first cuttings) - when my sister and I left home the cacti were left with my Dad, who repotted them several times, watered them, looked after them and probably spoke to them on several occasions.
Now the catci live in our porch in Abingdon and this year they produced these remarkable flowers:.
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Although stunning, the flowers only last for 24 hours before withering.
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But thanks to the twitter feed of the Oxford University Museum of Natural History (https://twitter.com/morethanadodo) it has finally been identified as Echinopsis eyrieslli - a native of South America, where it is also known as, rather appropriately, the hedgehog cactus.

The rarest plants in Oxfordshire?

Situated in south Oxfordshire, just a mile from Goring is Hartslock, a small nature reserve managed by BBOWT. Here, not only does the chalk grassland hill provide excellent views of the Thames valley:
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It also provides the habitat for three of the rarest plants in Oxfordshire - the small monkey orchid (Orchis simian), so named as it's flowers form the shape of monkeys is found at this one site in Oxfordshire and at few in Kent and Yorkshire (although it is more common in Europe)
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Whilst there are several monkey orchids, this year there were only two lady orchids (Orchis purpurea)  - which may have been introduced to the site in the 19th century, as the plants share more DNA with those found in Europe then those found in the UK. 
Like the monkey orchid, it gets it's common name from the shape of it's flowers, they are said to resemble ladies - with a hat and a long dress.  Like the monkey orchid, it is found at a very few sites in the UK
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But what makes hartslock special is that it is the place in the UK where these two species of orchids have hybridised - producing a lady-monkey orchid (Orchis simia x purpurea) - producing an flowers with the hats of the lady orchid and a body similar to the monkey orchid:

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Like most hybrids, it is considerable taller than the two parent plants and whilst there are only two lady orchids in flower this year, there are several hybrids.  So maybe, over time, the hybrids will replace one of their parent plants.
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For more information on these fascinating plants, their location, when they flower and the rather sad history of the site, there is an excellent blog written by one of the reserve wardens http://hartslock.org.uk/blog/