The State of the UK's Butterflies 2011

[Pete Eeles]

From the home page:

Today sees the publication of Butterfly Conservation's The State of the UK's Butterflies 2011. The report shows that almost three quarters of UK butterfly species have decreased in population during the last decade. More specifically, the findings by Butterfly Conservation and the Centre for Ecology and Hydrology (CEH) show that 72% of species declined in abundance over ten years and distributions of 54% of butterflies fell, many sharply. The report comes from data gathered by two long-running citizen science projects - the Butterflies for the New Millennium (BNM) recording scheme and the UK Butterfly Monitoring Scheme. The full press release can be found at http://www.ukbutterflies.co.uk/pressrel ... status.php.

Cheers,

- Pete

[David M]

I picked a copy of this up at the recent AGM and parts of it made worrying reading. That said, it was heartening to see several species extending their ranges (particularly into southern Scotland).

Pearl Bordered and High Brown Fritillaries remain the stand out species in terms of losses, though Duke of Burgundy looks precarious too.

[essexbuzzard]

I too have seen the very worrying press release. It makes sad reading indeed!
However,is it just possible in some cases that the aparent decline reflects a reduction in recording effort, rather than a real big drop in abundance, at least in the case of the more common species?
For example,if we look we see the Essex Skipper near the top of the decline in numbers list. As someone who lives in the heart of Essex skipper country (Essex!),it is second nature for me to check all the skippers i can get close enough to. And, allthough i have done no scientific survey, it is a common species throughout the area, and although it seems to prefer drier sites than Small Skipper,it is equally widespread,and probably the more abundant of the two on some sites.
Also we have endured some pretty average summers in recent years, including this year,do some of the changes reflect this?
Just my opinion, i am happy to be corrected regarding recorder effort!
Regards,Mark.

[ChrisC]

and the report viewed here http://www.butterfly-conservation.org/u ... 202011.pdf

[NickB]

I think some of the declines are a result (here in the S. East, at least) of housing and industrial developments on our brown-field sites, particularly when it comes to our commonest (sic) butterflies. Brownfield sites (such as railway sidings, old industrial estates & sites plus those small vacant building plots dotted around our towns and cities) were strongholds for wildlife of all kinds; many of these areas have disappeared in the housing boom of the late 1990's and early 2000's, so it no surprise that butterflies have suffered. Such piecemeal habitat loss is not noted at the time, but the cumulative effects are now possibly showing......
Some will say that these sites are preferable to green-field sites; I would contest that many "green-field" sites on arable and farmed land would be of less importance than some of those brown-field sites, so far as lepidoptera are concerned.....
N

[David M]

A common theme appears to be that the species not too fussy about their habitat are enjoying an increase in their ranges (Commas, Speckled Woods, Hedge Browns, etc), yet the likes of Pearl Bordered Fritillaries, Silver Studded Blues, Large Heaths & Grizzled Skippers are all declining.

Perhaps this is as a result of gradual climate warming which allows those varieties of butterfly that can colonise over distance the opportunity to do so, yet those that are restricted due to there being no suitable ideal habitat within striking range cannot.

Surely it at least proves how butterflies are one of nature's most effective barometers of overall environmental health.

[essexbuzzard]

Quite agree with you Nick,the importance of old railways, building sites etc,cannot be over estimated.
Look at how many Grizzled Skipper colonies are restricted to dissused railways-Goss Moor in Cornwall and in East Anglia,for example.
And most of these have very little protection.
Regards, Mark.

[Dave McCormick]

I have noticed here in NI, the small heath is in decline in some areas but in many of the areas its found, its still quite common and there is a project here to try and make sure dingy skippers survive. I am not sure if its been started yet or not, but people were going to make dingy skipper shaped stands on side of the roads where its found, and have its foodplant growing out of the top of it, with info about the skipper on it, which I think would get more people aware of it.

Some will say that these sites are preferable to green-field sites; I would contest that many "green-field" sites on arable and farmed land would be of less importance than some of those brown-field sites, so far as lepidoptera are concerned.....

I agree with you on brownfield sites, they have not been worked to remove "weeds" and other growing plants, which are essential to the insects and other animals. If I had my way, I'd make it compulsory for any new house to have an area for wildlife around it, hedgerow and wildflowers, but alas it won't happen unless people decide to do that themselves.

I know that here in parts of NI, the weather could have impacted some species (Peacock, Small Tortoiseshell) since I know there are still nettles abundant in many places these are found, but their numbers crashed this year.

[hilary]

In relation to the Brown field/Green field observations, It would be interesting to know which of the 'green field' crops are the most destructive.
If foraging winter birds can be taken as a kind of indication, then from the arable fields nearby me Carrots top the list. I doubt if even the margins totally escaped the drift of the many pesticide sprayings. A 2 yr silage/grazing crop of grass and clover was the least and kept hundreds of redwing and fieldfares happy for weeks.
Many butterflies and other invertebrates need permanent pasture, and the grazing or hay provide some return for the farmer, but as far as I know doesn't qualify for any of the subsidies, but I think deserves one more than some of the oher schemes.