Friday 23 December 2016

End of the Year

We have been in the new house for exactly 6 months at the end of December.   The estate was built on a marshy field with a hedge down both sides but little else in the way of vegetation (I think the field was only ever used as a pasture); a few householders have planted trees, but not many which is a pity.  Birds are therefore rarely seen in the garden at the back of the house, but the hedge in front has proved popular, as has the pond 100 yards away at the top of the estate..   In the 6 months since we moved in we have counted 26 bird species, the latest at the end of last week were a pheasant and a wren.   Here is the list:
House sparrow Magpie Red kite
Blue tit Starling Buzzard
Great tit Blackbird Little egret
Long-tailed tit Crow Robin
Bullfinch Redwing Mallard
Chaffinch Fieldfare Pied wagtail
Goldfinch Song thrush House martin
Greater-spotted Woodpecker Dunnock

House sparrow

Greater spotted woodpecker

Fieldfare

Redwing

Chaffinch

Little egret

There is nothing exceptional on the list and there were no greenfinches, coal tits, jackdaws, yellowhammers and so on which might be  plausible.  As the estate matures and gardens are established, it will be interesting to see the impact.  Hopefully it will create greater diversity, which might seem odd given that we started with a green field!

So far just 3 mammals, muntjac, pipistrelle 45 bats, and fox.   We saw another fox last weekend at 3.40 am - its barking woke everyone up.

I have adjusted my moth count to 104 because I missed out one trapping night, and a red underwing seen in the day time against the brickwork of a neighbour's house.  The commonest by number have been:

1 Brimstone
2 Setaceous hebrew character
3= Large yellow underwing
3= Dark arches
5 Heart and dart
Dark arches

Brimstone

The results are however unrepresentative because we missed most of the autumn.   Next year I plan to trap at least monthly, and more often in the warmer summer months.

Yesterday I walked over towards Whichford.  A common oak tree  had dropped its acorns or rather the knopper galls that had overwhelmed it; the tree is a full 1.7 km from nearest Turkey oak that I know of in the village.   A few weeks ago I met Mick Crawley who in the 1990's researched knopper galls.  Interestingly he could not nail down just how far from a Turkey oak the fly responsible, Andricus quercuscalicis will travel between the two oak species needed for its life cycle.   The females are just about to emerge from the galls and I brought back a few galls to examine them when they emerge.

Friday 9 December 2016

Annual Moth Count

As light relief from preparing my tax return I tidied up the moth count for the year, working through those that on the first pass earlier in the year I had not identified.   Most of them were micromoths, whose identification is testing and laborious, and there were times when the tax return looked more fun.   The species count for the year was a very modest 98, though I missed the whole of the autumn because the moth trap was trapped behind boxes in the garage, following our house-move.   Also the numbers at our last house were much lower than in previous years, which I am sure is down to tree removal in the surrounding area.  I am hoping to get a regular count throughout the year in 2017.  Around 40% of the moths I have seen in Hook Norton were also present on Skye, 500 miles further north in a quite different habitat.

With it being a mild, around 10°C yesterday evening, winter moths (the 98th species of the year) were everywhere, especially under the oak tree nearby.  Only the males fly.  The females crawl up trees and after mating lay eggs there.   The resulting caterpillars can then damage fruit trees.  I suppose I should protect my recently planted plum trees but with a bit of luck the blue and great tits attracted by the industrial quantities of bird seed that my wife puts out in our bird feeders, might do the job for me.



The hedge in front, which has lots of hawthorn berries, is now a feeding area for migrant fieldfares. (Will Brexit put a stop to bird migration - coming over here, eating our food etc. etc.  It's a disgrace.).  We have counted at least 20 or 30 or so in one cloud, with a few intermingled redwing.    There is a nice piece on thrush migration on the BTO website BTO Thrush Migration; fieldfares are coming from Scandinavia, whilst the redwings come from a slightly larger area of North East Europe but with birds from Iceland also.


Thursday 24 November 2016

Starling Murmuration - Otmoor


The Ashmolean Natural History Society of Oxford is a long established group for people with a catholic interest in natural history and provides a series of lectures and field meetings.   Yesterday they organised a walk through the RSPB reserve at Otmoor led by the RSPB warden to see the starling murmuration there.

Around 25 miles from Hook Norton, the reserve at Otmoor was created less than 20 years or so ago when agricultural fields subject to flooding were converted into a semi wetland  - some permanent water in reedbeds supplemented by winter flooding of grassland elsewhere.  We saw, interalia, wigeon, mallard, Canada and greylag geese, kestrel and red kite, lots of goldfinches and critically examined blackthorn tagged last winter where black and brown hairstreak eggs were found in a survey last winter (but finding nothing).  But this was not a twitching trip; the main purpose was to see the vast flocks of starlings which gather around dusk and the murmuration that follows as they begin to roost in the reedbeds.





At Otmoor the numbers of starlings that gather is estimated at anything between 50,000 and 150,000. Birds seem to fly in from every direction but before they roost they put on a spectacular display, the murmuration.   It is quite extraordinary, especially if there is bird of prey around, such as the peregrine falcon we saw yesterday.   At Otmoor the numbers of starlings increase in the autumn; the local birds which gather in September are supplemented by immigrants from the east (will numbers crash after Brexit?) reaching a peak in November.   Murmuration is a medieval term, derived from hunting, and probably derives from the soft humming sound the vast roost makes.

A bonus was sightings of three hares, one of which sat quietly as I got within 10 metres of it.   We did not see any otters, but they are there and we will make another visit in two or three weeks to see if we can spot them.



Tuesday 4 October 2016

Small Mammal Activity

Last night I attended a lecture organised by the Oxfordshire Mammal Group, given by Dr Paul Chanin about dormice.  I had not met Paul for almost 20 years when I was a member of a group led by him to the South Uists almost twenty years ago to look for otters.   That introduction developed into a complete fascination for otters and one of the reasons why we lived on Skye for 12 years.

There are very few sites for dormice in Oxfordshire; the Chiltern woodlands in south Oxfordshire, Buckinghamshire are a mainstay, and it was there when I helped with a nestbox survey that I saw my one and only dormouse.  Interesting was one of Paul's observations that they are more catholic about habitat than was once believed.  The classic habitat is hazel woodland, but it seems that they will nest in hedgerows, and even culm grassland.

Could they be more widespread?   There are no records anywhere near Hook Norton, but maybe we need to look a little harder.  I took a look at the hedge in front of our house - several feet thick and probably old with the right combination of foodstuff such as hazel, crab apples, sloes and brambles, and hawthorn in Spring,-  not surprisingly, but defying hope the survey proved negative.   But also not surprisingly there were quite a few nuts which had been chewed by woodmice - vertical chisel marks with scuffing at the top.  
  
       


We have also got moles working away at the grass verge beneath the hedge.   I have never seen a live mole; dead ones only - farmers up in the Lake district used to catch them and pin the dead bodies to a fence - I know next to nothing about them and in my naïveté I put out a trail camera where there has been activity.  Nothing, apart from a couple of pigeons and house sparrows.   I think some proper research is needed!


Friday 2 September 2016

Knopper Galls

Knopper galls are new to me, but there is an oak tree near our house which has lots of them.   They are caused by a gall wasp, Andricus quercuscalicilis, which lays an egg in developing acorns.   In turn this leads to a chemical reaction with the result that the acorn becomes grossly misshapen and host to the insect grub.



The wasp is an alien, and was first recognised in the UK in the late 1950's and early 1960's.   Judging from NBN data it now seems to be present throughout most of the UK, though remains commonest in the south and east.

I had a brief foray into the literature and there is some interesting work from the 1990's by Mick Crawley and others about the ecology of the wasp see eg. Hails and Crawley, where they were seeing as many as 60% of the acorns were affected.  Our tree, a native English, pedunculate oak,  had approximately a third of its acorns affected by galls.   The gall wasp does not damage the tree, just reduces the number of fruits.

At this time of year the grubs are just developing in what looks like an oval egg-case inside the disfigured acorn.  Often other parasites are found in the gall but I found only the gall wasp in the two galls I cut open (and getting a very sticky mess in the process).



The really interesting thing though is that the wasp needs not one but two host species.  It has two generations, one asexual the other sexual, each dependent on a different tree.   In addition to the native oak where the asexual wasp lays its eggs, there is a second generation where the emerged insect mates and eggs are laid in the buds and catkins of the introduced Turkey oak.  

I therefore spent an hour this afternoon looking for Turkey oaks around the village.   The nearest I found was a big old tree at the school, next to a younger native oak, whose acorns were affected.   The distance between the Turkey oak and our oak is 320 metres if the gall was flies in a straight line and does not get diverted.  How does the gall wasp find the host?

Thursday 1 September 2016

Early Days - a New House

We have moved within the village from a 17th century cottage, to a new house on an estate at the edge of the village.  The house move was not that stressful compared to the challenge of getting internet access.  It took 6 weeks to get broadband, due to the obduracy of Openreach, and we gave up contact with the world whilst we waited.   At one point we were told that no broadband service was possible because the nearest telephone cabinet was over 4km away rather than the 300 metres it actually is. We have now thankfully travelled forward from the 20th century to the 21st.

The estate is built on what was a pasture, and we face the original hedge which was the field boundary.  Needless to say that the development was controversial because of its siting, and there is still a lot of opposition even though it is now built.  It should all settle down in around 10 years or so, judging from another controversial development back in the 90's.

The hedge is a mature with hazel, blackthorn, field maple, crab apples, ash and pedunculate oak.   Behind lies a playing field and beyond that open countryside.   So far we have had a fox stroll by, and a muntjac exploring the hedge. as a scratchy video from my mobile demonstrates  https://youtu.be/Nx2mzNUMGIU.   3 families of mallard ducklings were raised on a nearby pond, and a piece of land which regularly floods and had standing water until the end of July had a Little Egret.

Within a couple of days of moving my wife put up three bird feeders - peanuts, grain and niger seed. (We are now back to dispensing industrial quantities of bird feed).   Blue and great tits were the first to appear on the feeders followed by dunnock and robins.   Goldfinch arrived only after a few weeks but they are now regulars.   From time to time we get clouds of housemartins circling around, occasionally perching on the roof.



A few butterflies so far including Speckled Wood, Large White, Small Tortoiseshell, and a Painted Lady.   This Southern Hawker Dragonfly has been a regular.


Early days!

Thursday 9 June 2016

More Marsh Orchids, This Time Southern and Early

Statistics might prove me wrong but by shear volume of visitors, many on large charabangs on day trips, Bourton-on-the-Water in the summer is probably the most popular tourist spot in the northern Cotswolds.  We don't like crowds and as a result we hardly ever go there, but I have now found a very good reason to visit. On the outskirts is a Gloucestershire Wildlife Trust reserve, Greystones Farm which includes the Salmonsbury Meadows SSSI, a wet meadow, on the banks of the meandering River Eye - wonderful on a bright early summer day as today was.  
 

The meadow has decent populations of Early Marsh Orchid (Dactylorhiza incarnata ssp incarnata - the pale pink form) and also Southern Marsh Orchid (D. praetermissa).   The variability of marsh orchids is curious.

Of the 6 species of Marsh Orchids (Dactylorhiza) in Britain, in my experience 2 show little morphological difference and are unmistakeable (Northern Marsh and Early Marsh - other than the readily recognisable subspecies which are different colour forms), but others such as Common Spotted, and Heath Spotted are very variable both in the colour, spotting on the leaves and marking on the labellum.   They also seem to be catholic about their preferred habitats.  (I commented on the taxonomic issues with Narrow-leaved in an earlier post).   Southern Marsh also seems to show variability;  I saw a deep magenta form on the A34  two weeks ago, and whilst the plants I saw today had a consistent paler hue the labellum shape and the degree of spotting on the leaves were variable.   New Flora of the British Isles ("Stace") has it that the leaves are usually unspotted, with a labellum which is shallowly 3-lobed.  










Between 10 and 20% of the plants at Greystones were spotted.  Are the spotted ones true to the species, or has there been some introgression with Common Spotted, though I found no plants of the latter on the meadow?  The labellum shape was variable, but there seemed to be no correlation between shape and whether or not the leaves were spotted.  The other characteristics matched up to the description in Stace.  Both the spotted and unspotted leaves had a few stomata along the veins of the upper surface of the leaves, consistent with Southern Marsh -Vegetative Key to the British Flora ("Poland"); by contrast Common Spotted only have stomata on the lower surface.   My conclusion therefore that these were in fact all Southern Marsh but the spotting may be due to variability or a small degree of introgression.

Nearby plants included Meadow buttercup, Ribwort plantain, Creeping cinquefoil, Red clover, Fescues, Hard rush, Meadowsweet, Silverweed, Hairy sedge, and Common mouse-ear.

There was plenty of non-botanical interest: inter alia lots of Blue Damselflies, Beautiful Damoiselles and on the Lakes, a close-up of a Great Crested.




I came home via Upper Slaughter; three weeks ago the emerging orchids there were only in leaf.  Using Poland I had them down as a mix of Common Spotted and Southern Marsh.  I went back today to see if I was correct.   Actually not quite.  They all had the appearance of Southern Marsh but about 50% had quite heavily spotted leaves.  I came to the conclusion that even though there were no Common Spotteds around these were  hybrids, D. x grandis (leaves had no stomata on the upper surface, and edge in parts like that of Common Spotted - Poland again).  The flowers had more the shape of Southern Marsh.  Here's an example: 



I will try to give orchids a rest now for a day or too. Orchid non-enthusiasts can rejoice in that it is quite a short season.


Wednesday 8 June 2016

Moths and Badgers: Close to Home

In the trap on Monday morning were 17 moths, 10 species.   The most spectacular, and new to me, was a Scorched Wing, whose appearance is unmistakeable.


That evening we went badger watching,   When we first moved to Hooky there were two setts within about 2 km of our house, one of which was long established with at least 13 entrances.   The badger population has invreased significantly and now there are at least 4 setts near the original, some of which are now quite large.   We went to one observing from the top of an embankment above the sett.

In the past I have use an infra red lamp with night vision scopes, but it is fiddly, so this time I tested out the simpler approach of using a red lamp.   They did not seem bothered by it, and we watched a family for around 30 minutes.  The camera shutter, even on it's quietest setting caused the most alarm.

An adult emerged at 21.43 and snuffled around in the undergrowth, then nearly 10 minutes later 3 cubs and another adult appeared.  The cubs stayed close to the sett entrance.





In and around the bird feeders we have had a couple of Wood Mice and a Greater Spotted Woodpecker.

Tuesday 7 June 2016

Botany on the 17th Fairway - Narrow-leaved Marsh Orchids

I was invited today to join a small group monitoring a calcareous fen, a SSSI, a few miles west of Oxford.  It is in the middle of a golf course - the 17th fairway, I think -  and we had permission to survey whilst the course was under maintenance for around 3 hours.   Despite being small, a fragment of former times, it is botanically rich and one of the highlights is a colony of Narrow-leaved Marsh Orchids.   I will purposefully refer to them by the common name because the taxonomy has been a matter of discussion for some time.  

They do look different from other Marsh orchids; the leaves were narrow, around 8mm wide, mostly faintly spotted and keeled.   The flower spike of 29 of the 44 I counted was distinctly one sided, just like the Narrow-leaved marsh orchids I examined on Skye.   The labellum also looked different, some way between that of a Common spotted and Southern marsh.   All were a pale pinkish purple, far less striking than those on Skye.




 

I am not sure if the taxonomy is fixed.  Skye also has narrow leaved orchids; they used to named Lapland Marsh Orchids (a brilliant name reminding us how far north Skye is, as with other plants found there such as Iceland Purslane), Dactylorhiza lapponica.   These are examples of plants I found there last year in late June.




Molecular comparisons with European populations reclassified these as Dactylorhiza traunsteinerioides along with other scattered northern populations in Britain in, for example, North Wales and North Yorkshire (the plant is never common).   By contrast it has been suggested that the southern populations, those south of a line from the Severn to the Wash, be regarded as a variety (?) of southern marsh orchids, D. praetermissa.   Whether this is now the accepted position, I am not sure; I am not at all sure in fact how taxonomic changes are communicated to the wider world (probably not well, judging from my colleagues - all very competent botanists - over this one example).

The plants I saw today had more similarities with Dactylorhiza traunsteinerioides from elsewhere than D. praetermissa, as can be seen looking at the Oxfordshire and Skye plants, though admittedly there are some differences.   The latter are for example more heavily marked but I believe that it is generally accepted that anthocyanin colouring is heavier the further north one goes.    I made some physical measurements of the plants I saw today and when I have a moment I will compare them with similar measurements on the Skye plants.

So whatever the current taxonomic thinking thankfully the vernacular name works rather well for the plants at both locations.

Inevitably with Marsh Orchids, one plant we found today defied classification, and might well be a hybrid between Common Spotted and Narrow-leaved, with heavier spotting on the leaves consistent with Common spotted, which were coming into flower nearby.   It is probably not worth dwelling over however.