Where Have All The Butterflies Gone?

Update Number 1:
Welcome to 2016. A new year begins and hopefully it will be a good one for all of us, and here I include  our local Lepidoptera. 2015 ended wet, warm, windy and grey in the county, and as a result very few sightings were noted, with just a couple of ‘unidentified’ butterflies (one white and one brown) putting in an appearance in December. Looking ahead to this year, we are still awaiting our first sighting of the year, despite the mild winter continuing into January. For those of you eagerly awaiting your ‘first of the season’; by comparison last winter’s firsts were seen on the 9th of February, with a Small Tortoiseshell and a Red Admiral being recorded, followed by a Peacock on the 4th of March and a Brimstone and Comma on the 7th of March. If you see any of the above over the coming weeks then please let me know.
The end of last year saw the release of the ‘State of the UK Butterflies 2015’ report. The report assesses the status of each of our resident species and a few summer migrants, plotting their increase or, in many cases, decline over the last forty years (1976-2014) using data taken from the UK Butterfly Monitoring Scheme (UKBMS), and also the trend over the last ten years (2005-14) using data submitted to the Butterflies for the New Millennium  program(BNM). The UKBMS uses the information recorded on the numerous Transects that take place throughout the season, thus highlighting how extremely important butterfly transects are, and also the sightings that people like you submit to the County Recorders.
Before looking at individual species it may be worth pointing out how the changes in habitat, in England, that have occurred since 1976 where the Report starts, have affected our butterflies.
Habitat specific species     -26% ( -12% in the last years)
Wider countryside species -30% (-18%)
Woodland species             -55%  (-27%)
Farmland species              -57%  (-37%)
The overall trend shown by our native butterflies over the last forty years shows cause for concern, with over two-thirds of our butterflies showing some degree of decline, and some of those with dramatic changes indeed. I will now try to give a relatively brief summary, focussing on some of the butterflies that are found in the county, and apologise now for bombarding you with statistics, but please bear with me.
The biggest loser is one that attracts the most interest in the county, namely the Wall Brown. Nationally, this butterfly has shown a decline of 77% in occurrence and 87% in abundance since 1976 (36% and 25% respectively over the last 10). Now the Wall Brown is somewhat of an enigma as the reason for this marked decline is not known. We know that they are becoming more of a coastal butterfly and careful monitoring is required to check their progress in the county over the coming years. The Small Heath is also showing signs of decline with a reduction in occurrence of 57% and abundance of 54%. All species of Hairstreak seem to be suffering, with the White-letter Hairstreak perhaps suffering the most with a drop of 45% in occurrence and a staggering 96% in abundance over the last forty years. Of course, Dutch-elm disease would have played a key role in the early days and trials to find a disease resistant form, and to identify other alternatives have taken many years to come to fruition, and it is probably too early to see any significant change in WLH fortunes. The Green Hairstreak has also suffered losses (30% occurrence and 41% abundance) over the same period, and this species will be one of my key focus points in 2016. More about this in future updates.
Our Skippers haven’t fared much better I’m afraid to say. The Dingy Skipper has declined in occurrence by 61% and 19 % in abundance since 1976, although there are signs for optimism here with the trend over the last 10 years showing increases of 21% (O) and 69% (A) respectively. The Grizzled Skipper has also declined  some 53% in range and 37% in numbers, although the last 10 year trend shows that the decline has been halted, although not, as yet, reversed. Those summer stalwarts, the Small Skipper and Essex Skipper have also struggled since 1976. Although the occurrence of Essex Skippers has increased by 104%, numbers have declined by a worrying 88%. The abundance of Small Skipper has dropped by a comparative 75%.
The picture painted so far does not bode well, yet here I must point out that there are ‘winners’ in the Report. The Silver-washed Fritillary has continued it’s march North-eastward over the last forty years increasing occurrence by 56% and abundance by an impressive 146%. The Marbled White has also increased in both territory and numbers  (29% (O) and 50% (A)) and is becoming more widespread in our county. The biggest gain since 1976 was shown by the Ringlet with an increase in abundance of a whopping 381% (72% in the last 10 years). Its summer companion, and perhaps one we take for granted is the Gatekeeper, and numbers of this species have not mirrored the success of the Ringlet. Gatekeepers have declined in numbers by 41% over the last forty years, and 44% in the last ten. A worrying trend for one of our most familiar butterflies. The Chalkhill Blue has increased in occurrence by 50% (8% in the last 10 years) and abundance by 20% (55% in the last 10 years), and has been recorded at Bloody Oaks Quarry, Rutland for the last 3 years. Hopefully it will remain a permanent fixture at this site, but whether there is any other suitable habitat nearby awaits to be seen (there is another colony over the border in Lincolnshire so it may not necessarily be an impossible task).
There are many reasons suggested for the decline in our butterflies; climate change, changes in agricultural practices, the use of harmful insecticides, habitat loss and pest infestation are a few of those mooted. Climate change may be beyond our control, but we can influence and even change the remainder on this list, and this will of course be Butterfly Conservations key role over the coming years.
I must reiterate here that all butterfly and moth sightings submitted either directly to me, or the county recorder or via our Facebook page are vitally important. Each one adds to the ever growing database and will contribute to future reports. I ask you all this coming year to let me have your sightings information, and your photographs and observations, and I will continue to share the information with others in this county, and also in neighbouring ones.
Please keep your eyes peeled for any early sightings, do plan ahead to get the most out of the coming year, and most of all, get out and about and enjoy our local Lepidoptera, as we all try our very best to ensure they remain here for future generations to enjoy.
I wish you all a Happy Butterflying 2016.
Posted in Leicestershire and Rutland Butterfly Line.