Sunday, 10 March 2019

Habitat work at Greenfield

I had a day out in the Chilterns on Friday and did some modest work on the two butterfly orchid enclosures at Greenfield.  The first leaves of the orchids were just visible, poking through leaf litter, and reaching around 3cm. 

Plant #85



Plant #203
Plant #100

       

Plant #77
Plant #209

Of the five plants illustrated, chosen at random, only one flowered last year (plant #100).  It might not repeat flower because it was not a particularly robust plant.  By contrast plant #85 did not flower but should do this year - its leaves were broad in 2018, a good indicator of what might transpire in the year following.  Plant #77 had 2 leaves last year, and although plant #203 had only one leaf then, it is obvious that it will have 2 leaves this year.  Plant #209 showed up early in 2018 but had disappeared by June when the full count was made.   It looks a little feeble.

The northern enclosure in 2018 had a thick sward of Dog's mercury which almost overwhelms the orchids.   It seems to be getting more aggressive, perhaps because more light is getting in with the ash trees suffering from ash die back. The problem it creates is that it smothers orchid leaves post-flowering, and chokes out light reaching them thus hampering the development of next year's tuber To check it, I strimmed the emerging plants and hand pulled bits that I missed.  This approach works on bracken; time will tell if I will have had any impact on Dog's mercury.

Before

After
Last year we had an increasing number of plants spreading outwards from the enclosures.  To encourage this spread I put a brush cutter over these areas.

Sunday, 3 March 2019

February Firsts

The warm and sunny period at the end of February brought about a rush of firsts of the year in my part of Hook Norton.

First moth:  Spring Usher. 



A new species for me, bringing my Hook Norton total since 2016 up to 243 species.   Last year we had 151 species, and in 2017 150 species, but with a lot of differences within those totals.
First butterfly: Brimstone
First hoverfly: Eupeodes luniger (on crocuses)



First bats: Common pipistrelle, (according to my Echometer Touch2) though the echolocation calls were atypical.  A spectrogram from February is compared below to one from October for a Common pipistrelle.  The former might in fact be a Soprano pipistrelle, but even then the spectrogram is odd with a bimodal pattern (at 50 kHz and 25kHz).  Maybe this has something to do with emerging from hibernation but I have to admit that I am baffled, and I did think it would be easy!


 

 Common pipistrelle? (Feb)    Definite Common Pipistrelle (Oct)