The Good And The Bad
Tuesday (7 June) was probably my last opportunity to monitor Duke of Burgundy numbers in Sussex this year, although I'll almost certainly pay a farewell visit to the most enduring colony, just to complete a Duke season that I'll remember and cherish for the rest of my days. My personal, running total for the year stands at 1355 counts which, when converted to an approximate hourly strike rate, is easily more than double my previous best years (2011 and 2014).
I watched a virgin female being run to ground by a string of four males; quite rightly, the fastest and fittest won. This was the sixteenth pairing I've observed this season, equalling my pre-2016 lifetime tally. As I wandered over the open slopes, well away from the lekking areas, I came across numerous females, laying eggs as they dispersed far and wide. The prospects for this species in Sussex have improved immeasurably over the last decade.
However, 2016 has not been so kind to most species. In fact, try as I might, I can't think of another which has done particularly well, even by modest 21st Century standards. Few have even attained a rating of 'average'. Many of our species are still sufficiently widespread and numerous to bounce back from a year (or should I say winter) like this, and many will do so quickly, particularly the multivoltine.
But it worries me greatly that the species which are currently vulnerable, whether nationally, regionally, or locally, are less likely to weather the storm which is blowing. This 'storm' is the increasing frequency of extreme weather events, courtesy of climate change. 2012, the summer that never was, wreaked havoc. I believe it was largely responsible for the subsequent extinction of Small Pearl-bordered Fritillary in Sussex. Lying in wait, I suspect, has been the tropically warm December of 2015. If you are a plant, or if you are butterfly species which over-winters in the larval stage of your life cycle, how do you react to that?
Having spent many years working on Duke of Burgundy as a volunteer, my focus has now shifted to encompass Pearls (PBF) and Small Pearls (SPBF), due to my BC
Fritillaries for the Future Project Officer role, so I know how bad the 2016 figures for Sussex are going to be. PBF did well at Abbot's Wood, and is currently secure at Rewell Wood, but elsewhere the news is far from good.
On Monday (6 June) I visited Bentley Wood, to catch up with a few species I have to travel for, such as Marsh Fritillary and Narrow-bordered Bee Hawk-moth, and also to spend time observing egg-laying preferences in SPBF. Watching about half-a-dozen female SPBF at work here last year provided some useful data, but this time I was clearly too early in the flight season.
On the bonus side, I bumped into bugboy as soon as I arrived in the Eastern Clearing, who very conveniently pointed out a docile, female SPBF (many thanks). A quick squint revealed that her wings were still damp, so it was just necessary to stand back and wait for the inevitable. She was grabbed without ceremony on a male’s third pass over the area. Fortunately, I was elsewhere when an outbreak of selfish behaviour occurred over ‘photographic rights’.
Despite it being a late season, what I saw worried me. According to the BC Hants & IOW website SPBF has been on the wing here since at least 26 May. Several observers have reported “five or six” individuals in the Eastern Clearing. I hope they are correct, but I came away only sure of having seen two males and a female. I sincerely hope that there is a significant number yet to come. A trek to more distant parts of the wood failed to turn up either SPBF or Marsh Fritillary.
One issue, the importance of which it is perhaps easy to overlook, is the alarming scarcity of nectar sources in the clearing, particularly the favoured Bugle. SPBF requires a lot of energy to sustain its busy lifestyle, and a shortage of nectar is likely to have a negative impact on the fecundity of females.
I’ll be watching the situation here with interest, and hope.