News from the Butterfly Conservation
County Butterfly Co-ordinator for Yorkshire Howard Frost

Howard Frost is Butterfly Conservation's Butterfly Recorder for Yorkshire. As a volunteer, he organises the butterfly recording effort for the whole county and with the help of an enthusiastic team of assistants, draws together the results in an annual report. He also works closely with those volunteers recording the moths, and has contacts with County Recorders in other parts of the country, as well as enthusiasts in Europe.

29th June 2008

Frost Report Update: 28/06/08 – I keep trying to be optimistic about this summer and its potential for seeing moths and butterflies. But each bit of news which reaches me persuades me that it is not to be! Last year, with all its heavy rain and floods, is now reckoned to have been the worst in 25yrs for the Lepidoptera (ie the butterflies and moths). This year shows every sign of suffering from the fewer eggs that were laid last summer as a result.

At least, the last two weeks have seen better moth numbers caught in our trap (in Withernsea, SE Yorkshire, not far from Spurn). On some occasions my wife has counted over 70 individuals of up to 19 species. Our house in the middle of an estate of over 100 dwellings and I am always surprised how many moths actually visit our back garden, particularly in a year when there have been hardly any butterflies visiting.

We continue to catch a handful of common immigrants like the Silver Y and Diamond-back, just as there continue to be a few Red Admirals around in the countryside, but my daily look at the continental weather forecasts, shows that weather over France has been far too changeable and cool to encourage much migration. The northern half of France has been in the same run of cool westerlies as ourselves, and only over the last 5 days or so have the temperatures around the Mediterranean begun to creep over the 30ºC mark at the hottest part of the day.

A friend who went walking in the Pyrenees two or three weeks back, hoping to see some of the rarer mountain butterfly species was taken aback to find high level paths still blocked with snow. He usually goes to the same area annually and has not experienced this before as late as June. Strange, in a year when scientists expect the Arctic Ocean to completely unfreeze for the first time since before the onset of the last ice age!!

A quick trip across the Yorkshire Wolds yesterday (June 27th), on a cloudy bright but windy day, revealed not a single butterfly flying. We took a brief walk across Millington Pastures, hoping to spot an early Marbled White, but no, nothing. We also visited our BC nature reserve at Elvington Air Museum where we went to finish off the first phase of the butterfly garden we are creating. It's a tiny garden, between two buildings, and all our planting is in pots. The idea is to link it through notice-boards to our three-acre nature reserve nearby. A quick look around the reserve revealed a dozen or so Meadow Browns, and a mating pair of Ringlets. Both these species should soon be common and widespread across the county, especially on road and track-side verges. A single Large Skipper was the only other species we had on the site, and indeed, these were the only butterflies of the day. (Please note the reserve is not yet open to the public, probably not till next year, and then only to paying visitors to the Air Museum.)

It remains a fact, that in the prevailing windy conditions with only fleeting periods of sunshine, you need to hunt out very sheltered sites which catch the available sun if you want to see any butterflies at all. We should be on the threshold of 6 weeks of maximum butterfly numbers, but unless we get more sun and less wind, the year is going to end up as no better than last year.

One bit of excitement for observers across the south and central parts of England this year so far, has been the number of Large Tortoiseshell sightings. Most occurred during that cool but sunny spell we had in April when winds were blowing from the east. That suggests an east European origin for such an arrival. There were also a handful of Camberwell Beauties recorded at the same time. If any of the Large Tortoiseshells managed to breed on arrival in England, their offspring will start to appear around now and may fly into the autumn before going into hibernation. During their flight period it is possible some could head further north! If anyone thinks they have seen one please note down full details and ask your VC Co-ordinator or our Webmistress for a rare species report form and return it accordingly. Thanks!!

7th June 2008

This last week I picked up the Annual Report from the printers. Copies are available from me at £11, payable to Butterfly Conservation Yorkshire. Sorry the price has gone up a bit, but its quite a weighty booklet and costs over a £1 to mail out. Still, it's excellent reading!

At last things seem to be improving although butterfly numbers across the county remain low. However, there is often a lull between the species which appear in spring and those which come out in summer, and that lull is longer if we get a spell of poor weather. At least we are seeing some immigrants arrive, with Red Admirals and Painted Ladies at Spurn, although no large numbers as yet. Perhaps not surprising with all the turbulent weather being experienced in France where central parts have had it exceptionally cold towards the end of this week, with temperatures ten or more degrees below average. I note from the website that a Painted Lady also reached as far north as Scarborough.

Immigrant moths have also been appearing in Yorkshire with up to 50 Silver Ys at Spurn and quite a lot of Diamond Backs. Spurn recorder Barry Spence has already notched up a new moth species for the county: Celypha rivulana, a tortrix moth. There has also been a local report of a Humming-bird Hawk-moth. General moth trap counts have been rising steadily this week and as tonight is National Moth Night the indications look favourable with some improving weather. In fact, it looks like the airflow will be coming in from Eastern Europe, which could make it extremely interesting.

Back to the butterflies, our typical spring species the Orange-tip and the Dingy Skipper are just about finished, whilst Common Blues and Small Heaths are beginning to appear. I had double figures of both on a Wolds site this week. On the other hand I have yet to see a Large Skipper although a few have been recorded elsewhere. This species is usually out and about in the SE of the county in the last week of May, but has evidently been held up by the cold weather we have had so far. Still, the signs are there. Summer could be approaching! Good moth-ing this weekend!!

24th May 2008

Apologies for a longer than planned break in these notes. I've been coping with builders! No news yet about the forthcoming 2007 Yorkshire Lepidoptera Report. I'm expecting a call from the printer any day.

From my perspective in the SE of Yorkshire, the butterfly season has been unusually slow to get going due to the cold east winds which have now been blowing for 23 days – a remarkably long period. Whilst there have been some warm days inland, coastal temperatures have only occasionally been above 12ºC and even then only for a short time in the day. At least there has been a lot of sun, but the wind has often been too strong for butterflies. In such conditions you have to be a detective and visit suitable habitats you know will be open to the sun but sheltered from the wind. That's where you will find the Orange-tip and the Green-veined White at the moment. There are also worn looking Peacocks and Small Tortoiseshells still about and I saw my first Small Copper last Thursday on our Elvington nature reserve near York.

On the continent it has been relatively cool around the western Mediterranean with day after day of thunderstorms across parts of Spain and much of France, although it has been much warmer in N France than in the south! SE Spain is becoming a desert with virtually no rain for months. Reservoirs are empty and water is being imported from France by the boat-load. Shrivelled vegetation is not much good for butterflies! One vigorous storm over S France left 15cm/6inches of hail on the ground. Not much good for migratory butterflies or moths even if they are trying to shelter! At least one Painted Lady and one Red Admiral reached Spurn on May 13th. They probably arrived in England with the wave previously reported. In N Europe temperatures have been slow to rise, with heavy snow in parts of Sweden. We really need some sunny calm weather!

3rd May 2008 at 9am

My predictions for last weekend turned out quite well. Unlike much of the county, and contrary to the forecast (!). the SE corner near Spurn, where I live had two quite sunny days although with cooling breezes off the sea. The French forecasters were also spot-on about the surge of warm air moving northward from Africa through France. This did indeed bring a wave of Painted Ladies northward reaching as far north as the S coast of England and apparently, according to the BBC4 project detailed elsewhere on our website, a Painted Lady sighting was made in Yorkshire.

Painted Ladies began to arrive in Spain in March and April and have begun to breed there. Where conditions are warm enough, the breeding cycle for this species can be as short as 6 weeks, so that could lead to a further wave moving north from Spain in the not-to-distant future – but always, weather and winds permitting!

The long Bank Holiday weekend across France looks fairly settled and sunny – with maximum temperatures ranging from 19ºC in the N to 28ºC in the S, where night temperatures are expected to remain high at 13ºC or above. This looks favourable for butterfly and moth migration, although the unstable conditions across Northern England may mean we don't see the results this far north, at least, not until later in the week.

Overall, the butterfly season in Yorkshire seems to be getting off to a very slow start. The hibernating species like Peacocks and Small Tortoiseshells are in evidence, but reports suggest that sightings are very patchy. Butterflies emerging from overwintered eggs and larvae are still scarce, but warmer weather promised for the coming week might encourage a change. When you are out and about searching for butterflies at this time of the year, remember they need warmth and nectar. The biggest nectar source in spring is the dandelion. So on any warmer days, look at patches of dandelions that are in sheltered, sunny positions and you will almost certainly spot a butterfly! Another good source of nectar is the May blossom (ie the Hawthorn flowers). You have to look quite closely to pick out white butterflies like the Green-veined White nectaring on white flowers!!

26th April 2008 at 9am

Warmer weather!

Well, the French forecasters were right! A plunge of warm air from Africa did head north during this last week and gave France and Spain almost cloudless skies yesterday and today with temperatures reaching 25ºC +. Unfortunately for us, the associated finger of high pressure ended up well to the east of Yorkshire leaving us in pleasantly warm but very unstable conditions. Still, there should be a surge of emerging resident butterflies as a result of the warmer conditions. There will almost certainly be migrants heading north as well, but at the moment it is uncertain as to whether any or many will reach Britain as the weather looks likely to break down into cloud and rain from the Atlantic on Sunday and Monday, not just here but in France and Spain as well.

We are currently into a period when the Pacific Ocean is cooling. The Pacific affects the climate worldwide with alternate warming and cooling periods each lasting about 25yrs!! The current cooling period started around 1995. Scientists have been unsure as to how far this would affect global warming, but some reports now indicate that global average temperatures stopped rising in 1998. This seems to be in conflict with other reports, so as a layman, it is difficult to understand where the truth lies! However, even if world average temperatures have slowed down or become static, they remain at an uncomfortably high point with Arctic and Antarctic ice sheets continuing to melt at an alarming rate.

The last cool period ran from the late 1940s (with the severe winter of 1947) to the dismal, cooler, wetter 1950s and 1960s. Those latter years were very poor for our Yorkshire butterflies and may have marked the beginnings of some of the losses which have more recently been exacerbated by habitat loss. The big question is: Could that downturn of the 50s and 60s be repeated today as we approach the middle of the current cooling period? We will only find the answer to that by keeping up our regular monitoring of butterflies and moths in Yorkshire!

My wife, Chris, has run her moth trap during the last three nights in the back garden of our Withernsea home, on the coast just north of Spurn. The total catch has been just one Hebrew Character. Let's hope for better soon! Howard M Frost.

21st April 2008

2007 Lepidoptera Report
I've been going cross-eyed in front of my computer screen for much of the winter, busily working on collating the 2007 Annual Lepidoptera Report. Thanks to all the excellent work done by members of the supporting team I was able to get it all to the printer by late March. It should be ready sometime in May. Once again, it will be a 112 page A5 perfect bound paperback with 16 pages in colour, showing off some of the best butterfly and moth pictures taken in 2007. And they are good!! I had over 1000 sent in and whittled those down to about 70. 1200 copies of the report go out free to members of BC and the YNU. 50 copies are retained for sale to non-members at £10.50 (inc postage) - still a bargain! Copies are available from me at 10 Chellsway, Withernsea, HU19 2EN - cheques payable to Butterfly Conservation. You are advised to send orders in advance as the 50 copies are usually all gone by the end of May. If you want acknowledgement of your order, please include an email address.

Change of weather
Did you notice it was the full moon on April 20th? The effect of the moon's gravity, not only controls the tides but can also effect the weather. When pressure systems get stuck in a rut, they often shift in the 2 or 3 days after the full moon. And that seems to be happening now. The long run of cold and gloom which has made this April so different compared to last year, is already shifting. This year's cold spring weather has extended far and wide on the near continent and right down to the Mediterranean where many fruit blossoms have been browned off by exceptionally harsh frosts.

However, French weather forecasters are now predicting a wave of warmth and sun spreading north from Africa. They are expecting it to advance up the east of the country on Wednesday afternoon (23/04) and by next weekend France should be bathed in sunshine with temperatures in the range 23-25ºC. If they are right, then we should see similar weather extending into Britain by next weekend. In fact, even today in Yorkshire it looks more promising with sunshine, even though temperatures along the east coast remain very cool. As this stream of weather will be moving out of Africa, it could bring an early arrival of migrant butterflies and moths, such as Red Admirals and even Painted Ladies and Clouded Yellows.

I try to follow the continental weather scene so as to pick up the situations which encourage migration. Last autumn was quite cold on the continent with some very early snowfalls. The ski resorts, which have been receiving less and less snow as the years go by, had a good year. But then in January parts of the Mediterranean coast had unusually high temperatures exceeding 22ºC. with people sea-bathing in the warmth. February and March have seen temperatures see-sawing between winter and summer. In some winters butterflies and moths can breed continuously around the Mediterranean. This is how Red Admirals and Clouded Yellows can produce big numbers to enable them to head north and give us some excitement. Painted Ladies usually build up their numbers in North Africa. So whilst some conditions last winter will have helped these species, others may not. However, it is better for most butterflies and probably many moths if they are not tempted to come out in winter. The later they emerge the better they survive. So, on the whole the cooler the April conditions, the better for most of our butterflies. A long warm spell in late April/May would be ideal!

Yorkshire butterflies
As you will see from our ongoing reports, only a few hibernating butterflies appeared during the winter. The first notable emergence came in late March/early April. On 04/04 I was delighted to find no fewer than 16 butterflies in my Withernsea allotment: 14 Small Tortoiseshells, 1 Peacock and 1 Small White. But they soon disappeared as the winds turned first to the north and then to the east bringing snow to some parts of the county. The snow came as a surprise to some as we seem to be getting less and less of it in our warmer winters. However, we are into one of the world's known cooler spells, and scientists have been wondering how far this might slow the effects of global warming. We could yet get some even harsher winters, but it doesn't mean an end to our climate problems! I grew up on the east coast in Scarborough and in the 1940s/50s this April would have seemed perfectly normal! Anyway, stand by for some better weather. This is the final year of our current 5-year recording project and we want as many records as possible sent in to us! It looks like next weekend will be good for a recording trip to somewhere! Howard M Frost