Saturday, 21 April 2018

Early Spider Orchids and Reptiles in Dorset

The orchid season has started; it is a bit like the first day of the football season, only better.   Football starts with that tiresome and pointless Charity Shield match, whereas the orchid season starts with a fanfare, with the first appearance of Early spider orchids in Dorset, in a wonderful location.  A European species, Early spider orchids are confined to a few spots on the south coast; it was curiously more widespread in Britain than it is now.  In a few spots near Worth Matravers such as Dancing Ledge there are hundreds.   I went there yesterday, on  a very warm, sunny day.   Perfect.










There were also a small number of Green-winged orchids.  



Besides the orchids, there were lots of other nice stuff.   A small group of wheatears in one of the arable field I crossed to get to the coast, several butterflies including Small tortoiseshell and Peacock.   Best though were the reptiles; I saw 2 Common lizards and this Wall Lizard pictured below (with identification help from a fellow orchid enthusiast - I was not aware it occurred in Britain), and the best sighting of an adder I have had, moving amongst the limestone rocks at St Aldhelm's Head.   Quite menacing and fortunately my wife missed this trip as I think she would have been terrified (a life-long ophidiophobe).



An excellent day, definitely worth the long journey and delays on the M3.

Monday, 16 April 2018

Upgrading the Protection for a Rare Orchid

Near to Kidlington, there is a lone lizard orchid by the roadside, discovered some years ago by Christopher Hoskin a stalwart of the Ashmolean Natural History Society, remarkably from just the leaf rosette (I definitely would not have recognised it in this way).  Quite how and why it is there is a mystery as the nearest location of any other plants is several miles away.

The road is not busy but sitting on the verge only around 1 metre from the carriageway there is a risk that a car might pull off and damage it.   The verge has been regularly cut, because it is near commercial buildings, and in past years there has been a stout cage over it with warning tape wrapped around the cage - not entirely enhancing the enjoyment of this amazing plant.

Not anymore.  There are now two stout 4 x 4 posts guarding the plant, presumably erected by Oxfordshire County Council ,who I think have responsibility. 




This plant is on Schedule 8 of the Wildlife and Countryside Act, 1981 and therefore has the maximum level of legal protection so quite how many people and organisations were involved in the erection of these posts, it's best not to speculate.   Nevertheless a good job done and I am a little happier this year in paying my council tax.

50 yards further on there was a bee orchid rosette and some muscari, probably M. armeniacum but I will check when they are in full flower that they are not M. neglectum.


Not far from there was a fungus, possibly false morel, but if not, I have no idea what it is.


Wednesday, 11 April 2018

First Leaves of Greater Butterfly Orchids at a Chilterns site.

I spent the day in the Chilterns yesterday taking a look at the Greater Butterfly orchid population that a landowner and I are monitoring there.

Leaves are appearing.   



We have two enclosures, North and South, separated by a track and fenced to keep out muntjac.  The Southern section is divided roughly in half, with one half designated as a study area.  There we counted  how many plants from last year were showing leaves.  Of the 56 plants from last year, I overlooked 8, leaving 48 of which 40 had leaves, rather higher than I expected.  4 plants had double leaves (which is a puzzle as they do not spread vegetatively) and there were 8 new plants, again fewer than I had expected. The population seems to be at an equilibrium, which is not surprising as it has been there for some years and has not been subjected to serious change. 

 Habitat management consists of bramble removal, but not every year.  We are though experimenting, and this year we removed bramble from the study section in January, but not the other half of the South enclosure.  There were only 5 new plants in that section compared to 101 plants last year, whereas in the North enclosure, where bramble was removed in January there were 30 compared to 186 plants last year.   On the face of it, bramble removal does seem beneficial, but it is probably simply a matter of being able to find plants more easily.   


The next visit will be in early May when buds should start appearing, but we don't expect flowers until early June, 7 weeks from now.   Then we will do a full survey of flowering and non-flowering plants, from which we can draw proper conclusions about population dynamics.

The orchids  seem to take longer to flower, shaded in the Chilterns, compared to those out in the open on Skye.   Buds around 24 v 18 days from first leaves, flowers 45  v 30 days from first leaves.  The landowner also noted that a few plants he has in a meadow always flower earlier than those in the woodland which we are studying.  

Yesterday light levels in the orchid enclosures were the same as in the open, but when the plants flower light levels are maybe 60% of those in the open, as leaf cover (mainly beech) intensifies. 

Friday, 6 April 2018

Repeat Visit to Whitehill Wood

We made a repeat visit to Whitehill Wood yesterday to see the Yellow Star-of-Bethlehem fully in flower; most were in bud 2 weeks ago at the time of the count.   We found 6 plants in flower, but with all the heavy rain over the last week (50mm at home) the Windrush was at a high level and at some point, probably last Saturday, it had flooded the path, covering the Yellow Star-of-Bethlehem and leaving them mud spattered.








They were even harder to see than usual, though it was much easier to find no-flowering plants, stark against the mud. 


It made it obvious just how little competition these plants tolerate, with virtually bare earth around them. Plants of Lesser Celandine, Dog's Mercury and a grass were scattered here and there but nothing else.

Another highlight was Toothwort, just beginning to emerge on the roots of hazel and buried debris.

We also found some nice otter prints.   Two weeks ago we saw spraint; maybe the real thing on the next visit (but in truth I doubt it.)


Overnight I ran the moth trap at home with 5 species caught.   All are common:

  • Brindled Beauty
  • Hebrew Character
  • Clouded Drab
  • March Moth
  • Common Quaker





  • March Moth
  • Hebrew Character
  • Clouded Drab

Sunday, 25 March 2018

Yellow Star of Bethlehem (Gagea lutea) - Why so few flowers?

It was the annual count yesterday of flowers of Yellow Star of Bethlehem (Gagea lutea) at Whitehill Wood by the River Evenlode.  A week earlier than last year after a cold Spring, there were no violets, primroses and Wood Anemone just emerging, and too early for toothwort.  We found only one flowering plant of G. lutea, with a few more in bud, a total of nine plants, I think, and fewer than the average for the last 7 years, 13 flowering plants.   We did not rediscover two plants seen in flower earlier in the week; maybe they were chewed off by deer, of which there are lots in the wood.

What is remarkable is how few plants flower.   There are hundreds of non flowering plants, which are distinguishable in leaf, with some experience, from bluebells by the single, hooded basal leaf with a "long, inrolled apex" (Poland and Clement).   I counted plants in a 5m strip on each side of the path (5.5m x 0.4m on the river side, 5.5m x 1m on the other side, a sloping bank), a repeat of last year.



River:  53 non-flowering, 0 flowering (20/0 last year)
Sloping bank:   40 non-flowering, 0 flowering (43/1 last year).

The percentage of flowering plants is tiny, but why?   Do the plants not develop enough once they have germinated to produce a flourishing plant or do they spread vegetatively, (but in that case there would be tight clusters which is not the case)?  It does of course 

Most plants were juveniles, but a few looked robust enough to bear flowers. In the wood above, which slopes quite steeply, there were plenty of leaves but no flowers.  This is replicated elsewhere and also seems to be consistent with the genus.   I remember from visiting years ago that it was also true of G. bohemica in Radnorshire - lots of plants but very few flowers.   

I have looked at the dataset and can find no reliable correlation with climate, other than a very wet June / July in 2012 was it seems linked to no flowers appearing in 2013.

They seem to prefer minimal competition.   There are none where ransoms grow, and tail off where the dog's mercury takes over.   

The one flowering plant faced the river at a point which was deeper than the height of my wellingtons, and the resulting wet feet in slippery mud might offer an excuse for these slightly out of focus pictures.



Wednesday, 21 March 2018

Westwell Gorse - Orchid Leaves

We went to Westwell Gorse, the BBOWT reserve near Burford today, to see what impact the snow and ice earlier this month had on the emergence of the orchids there.   Actually quite a lot; they were quite bedraggled, much less advanced than a year ago, and quite a number of leaves were damaged.  Rabbits had also been active chopping the tops of two of the plants of which I took an accurate position last year.  Here are a few comparisons of three Early Purple Orchid Plants  (Left = 2017, Right = 2018):

                                              

                            
               


At flowering time, as last year we will make a count to see if the frosts and snow have had a more lasting impact, though it looks as though the rabbits are the bigger problem.



  


Thursday, 15 March 2018

Firsts

Some sunshine and warmth.  Could this be spring at last (though snow is forecast this weekend)?

I recorded a few firsts for the year. 

The moth trap 2 evenings ago had the first moths for the year - 3 in total over a 4 hour period:

  • Dotted Border (the first I have had here). 
  • March Moth (as last year), 
  • Oak Beauty (seen in 2016 but not last year)

Dotted Border
 
Oak Beauty

March Moth

The first bees appeared in the garden:

  • A queen White-tailed Bumblebee on a hellebore
  • Honeybees on crocuses