July 2011

[Julian]

This is helpful Guy, and I am sure you are right.

Medium-sized as these QOS's may be, they are very powerful flyers and so a little trip across the North Sea would surely be not too great an obstacle. If there were a population eruption, it sounds extremely plausible that some move across to these shores and find a home and even breed here. The evolutionary or selective pressure upon them to do so to my mind seem far more plausible than anything else. It happens with other species. The Minsmere colony lasted several years until 1997 and the butterfly was recorded at this time from 8 different Suffolk sites. Pairing was observed at a nearby site on a number of occasions and individuals were seen coming off arable fields with field pansy their larval foodplant. Sadly, only one individual was seen in '98 and again in '99. This seems the likely end of the Suffolk QOS for that period. but it does seem to have an interesting history on these shores and this may prove invaluable if the latest one is part of a new colonisation.

Julian

[Julian]

Ok thanks Piers. It was interesting to have your views in any case.

Julian

[NickB]

I hear both sides; it is a half-full/half-empty situation. I too from a personal view tend to look at the sites and sightings and do no rule out the probability of an immigrant against a release, particularly on that coast, which has also seen large numbers (for the UK) of Camberwell Beauty and Large Tortoiseshell - not all of those are releases!
Always err on the side of reason, they say; no reason to assume everything is always a release, either....(tho' I take on-board the availability of captive stock and their popularity)
Either way - a stonking picture and butterfly!
Back in the mundane world - finally saw some Skippers out in the Cemetery at the weekend. It has been a strange season in there; no Common Blue, Brown Argus, Small Copper, Large Skipper or Small Skipper. As I suspected these (given the timing) are Essex Skippers. So what is so different that all the other butterflies I mentioned did not make it through the drought, but these did

100% crop of antennae

N

[dilettante]

I'm no expert (I've never knowingly seen an Essex Skipper!), but aren't those antennae the wrong shape for Essex? I thought they were always more club-shaped?

[MikeOxon]

Mmmm - tricky. The pointed wings look Essex but the antennae do look 'wrong'. Anyone know if hybrids exist?
Mike

[Piers]

So what is so different that all the other butterflies I mentioned did not make it through the drought, but these did

Could it be, Nick, that the types of grasses favoured by these smaller skippers (yorkshire fog, cock's foot, false broom, tor, etc.) are more drought tolerant than the types of food plant preferred by those species that did suffer in the east of England? In addition, the skippers may well choose grasses that are in areas that are slightly less prone to the rigours of a full drought than (say) the steep banks upon which grows horseshoe vetch.

Piers.

[NickB]

Small Skipper from elsewhere earlier this year....
.

Small Skipper, Roding Valley, 11th June

..crop of antennae...

.....re: Essex - I have been wrong in the past...
Another from today...

..crop of antennae...

[MikeOxon]

Went to Durlston yesterday (Monday 4th). Depite very hot sunny weather, butterflies were fewer than I had hoped and very active,making photography difficult. Lots of Meadow Browns and several Marbled Whites (though thinly spread). I chased several Skippers, which were proving very hard to follow, and most turned out to be Smalls, with just one Large seen. I evenutally foud my target species - Lulworth Skipper - close to the wall on the cliff edge. She posed just long enough for a photo and then 'skipped' over the wall towards the cliff edge.

Durlston CP - 4th July 2011

The seabirds have finished nesting on the cliffs but I got splendid views of a pair of Peregrine Falcons, calling loudly to each other as they sped along the cliff edge.

Mike

[NickB]

So what is so different that all the other butterflies I mentioned did not make it through the drought, but these did

Could it be, Nick, that the types of grasses favoured by these smaller skippers (yorkshire fog, cock's foot, false broom, tor, etc.) are more drought tolerant than the types of food plant preferred by those species that did suffer in the east of England? In addition, the skippers may well choose grasses that are in areas that are slightly less prone to the rigours of a full drought than (say) the steep banks upon which grows horseshoe vetch.
Piers.

...yes - for the CB, BA and SC; but why the Essex, and not the Large or the Small I would also expect? Since Essex are later, I suspect that the weather here broke just in time for them to make it...? I was also wondering about ants - the rest of the species I missed all utilise ants (or are attended by them) in some way; possibly their response to the drought may have had an effect on those species...?

[NickB]

.... a pair of Peregrine Falcons, calling loudly to each other as they sped along the cliff edge.
Mike

Fabulous sight!

[Piers]

So what is so different that all the other butterflies I mentioned did not make it through the drought, but these did

Could it be, Nick, that the types of grasses favoured by these smaller skippers (yorkshire fog, cock's foot, false broom, tor, etc.) are more drought tolerant than the types of food plant preferred by those species that did suffer in the east of England? In addition, the skippers may well choose grasses that are in areas that are slightly less prone to the rigours of a full drought than (say) the steep banks upon which grows horseshoe vetch.
Piers.

...yes - for the CB, BA and SC; but why the Essex, and not the Large or the Small I would also expect? Since Essex are later, I suspect that the weather here broke just in time for them to make it...? I was also wondering about ants - the rest of the species I missed all utilise ants (or are attended by them) in some way; possibly their response to the drought may have had an effect on those species...?

Additionally, Essex will use tor grass on some sites, and this has to be one of the hardiest of grasses least prone to suffering through prolonged periods without rain.

I do like your ant association though, although they are not essential for the succesful development of the CB, BA, AB, etc. Has there been a paucity of antage in the drought his areas? perhaps the ants became xenophobic and gobbled up a lot of the larvae that they usually so lovingly tend..?

[dilettante]

I'm no expert (I've never knowingly seen an Essex Skipper!) ...

I just went down to Magog Down outside Cambridge to look at skippers. I saw many small skippers, and some that I'm pretty sure were Essex. I wish I could be 100% sure! Annoyingly, I'd brought my camera to work, but left the memory card at home.

Also saw my first Gatekeepers of the year (quite a lot of them), several Marbled Whites (not seen them there before), plus Small Heaths, Meadow Browns, Ringlets, and unidentified Whites. A nice way to spend a lunch hour.

[NickB]

.... the ants became xenophobic and gobbled up a lot of the larvae that they usually so lovingly tend..?

A good source of moisture...? I read that species of butterfly, whose pupae and larvae are generalist mimics of a range of ants (rather than just one species of ant) are less successful than the specialists in deceiving the ants they co-habit with....but because they use a wider range of host ant, they are less restricted than the specialists....

Or maybe the ants moved their brood chambers down to cooler places and left the larvae to cook?
Or maybe it has nothing at all to do with it

Certainly, the high April temperatures and 1.9mm (yes a whole 1.9mm!) of rain we had that month just left everything dessicated and baked....

[Piers]

I read that species of butterfly, whose pupae and larvae are generalist mimics of a range of ants (rather than just one species of ant) are less successful than the specialists in deceiving the ants they co-habit with....but because they use a wider range of host ant, they are less restricted than the specialists....

That's interesting Nick. Nature is full of 'trade-offs' like that, such as the macropterous form of the Roesel's bush cricket; fully formed wings are great for dispersal, but the fully winged form has a poor reproductive rate.

Anyway, how was the silver studded blue emergence in Suffolk this year? No other English butterfly except the large blue has such a close relationship with ants, so perhaps their success (or not) would be an interesting place to start with your theory...

Piers.

[NickB]

Piers, life may be too short for that...
Suffolk BC 2009 SSB Report shows quite a lot of other work being done on those sites and other factors coming into play as well....
http://www.suffolkbutterflies.org.uk/do ... 09.low.pdf
N

[Julian]

Hi Piers

The Sandlings Heaths of Suffolk have had a hard time this year in so far as there has been a far poorer showing of Bell Heather, the most common nectar source for the butterfly in the area and fewer SSB's. Some of our colonies would seem to be producing far fewer adult butterflies which may reflect the harsher spring conditions when we observed a lot of dead or dying Bell Heather and other vegetation, caused, one would imagine, by the long drought, an etremely hot April, and a very severe late frost. I would like to give figures for Suffolk SSB counts, but the data has not yet been published by our recorder. However, I can say that a site that I am partially involved with is down about 50% in terms of adult SSB's and what is even clearer is that the flight season was very early. It's not all doom and gloom though. At some of our poorest sites, the butterflies were still flying and indeed at one, the numbers were up, although this doesn't say much other than that they are still there, since the numbers are so low that they fail the current statistical sampling technique used to calculate absolute and relative population size.

Regards
Julian

[Piers]

Julian,

Many thanks for the detailed, if somewhat depressing, response. It would be terrible if Suffolk were to lose it's particular geographical cline of species from the Sandlings. I know that an awful lot of effort is being put into conserving these populations.

Piers.
Ps: thanks to you also Nicholas.

[NickB]

Those sorts of peak figures do not surprise me - and there should still a good few hanging around, if Kelling Heath on the Norfolk Coast is the same as sites I've visited in Suffolk.
Large areas of mature scrub and heather have been cut or ploughed-out to extend areas of new growth at Kelling. Burns - accidental and deliberate (it is next to the NN Railway nr Holt)) - also clear areas. When I visited Kelling with PhilB & Rosalyn, on Sunday, we saw perhaps 20 SSB, generally rather elderly, males and a few females looking for places to lay.
N

[Philzoid]

Apologies for this being out of sync but I just wanted to post a couple of pics of the PE's I got to see at Straits enclosure last Saturday. Although I don't have an openwing shot apart from the camcorder still of a male, the first Emperor on the ground did not have any purple (I moved around to look at different angles to see whether it was down to the direction of the light).
Question, do female PE's feed on the ground and secondly can you sex them from the underside

The dung attracted other butterfly visitors including a Comma and two Red Admirals

First Emperor (female?)

Emperor male with Red Admiral and Comma

Second emperor (male)

Purple from video footage

[Julian]

Yes. Thanks Piers and Nick.

We shouldn't get too depressed though. There has been a lot of good work by volunteers and although things got bad with some of the sites, others were turned around and things improved and new habitat has also been created resulting in a successful translocations to another. So things can get better. But we need to support and encourage each other. People power can help. Martlesham Heath has ( I believe) just got HLS funding, which should help, and we are trying hard with the others. Some are doing really well. The RSPB sites for example are well managed and well wardened and throw up fairly substantial counts each year. But we do need support at some of the others which are failing, so you are absolutely right: this cline, the one I help to look after with other vols- is the very last of the Ipswich SSB's. I won't say much more than that, but your support, moral or otherwise, is urgently needed. We need to get people on board and turn it around or it will go. If that happens, all that will be left are the beautiful stained glass windows high up on the gables of .Sainsbury's and Homebase DIY superstores at Warren Heath, Ipswich, a stark reminder of how these two buildings cleared a whole colony out the way, splitting what was left into the smaller fragmented and at risk populations we have to deal with today.

Julian