www.ukbutterflies.co.uk

These are two Berger's images from the Var in April 2011...
Their identities are certain as I believe Pale does not fly, or is extremely uncommon here at that time. I can vouch for the difficulty getting the things to stay around long enough for a photo

I saw lots of Clouded Yellows in the UK in 2103, but I saw this Berger's Clouded Yellow in the Dordogne in July 2012.

It's interesting neither of the rarer clouded yellows seemed to make it to the UK this year, when clouded yellows were so common. Who knows what surprises 2014 will bring - a few Berger's clouded yellows would certainly be a treat, though there would be a lot of ID queries in the pages of UK Butterflies, I think!

This one is a male, in a meadow near me:



Guy

Guy and others,
Are you able to point out the differences between a pale clouded yellow and a Berger's clouded yellow,similarly to the way we were shown the difference between a Clouded and Pale clouded earlier in the year?
P.J.U.

Have you seen this?:

http://www.ukbutterflies.co.uk/species. ... %20Species

Cheers,

- Pete

It's probably not possible to confidently differentiate these two species even with a clear view (courting) of the uppersides of both sexes, as a recent example has shown. The consensus was alfacariensis although one highly respected expert thought there was a case for hyale. It's easy on my patch as Reverdin has noted, because hyale does not occur in Var.

This might be of interest: http://felixthecatalog.tim.pagespro-ora ... iensis.pdf

Roger

Roger Gibbons wrote:It's probably not possible to confidently differentiate these two species even with a clear view (courting) of the uppersides of both sexes, as a recent example has shown. The consensus was alfacariensis although one highly respected expert thought there was a case for hyale. It's easy on my patch as Reverdin has noted, because hyale does not occur in Var.

This might be of interest: http://felixthecatalog.tim.pagespro-ora ... iensis.pdf

Roger

That's a most interesting resource, Roger. Thanks for sharing.

All this is true. Nevertheless, the majority of individuals, in my experience, can be identified in the field. I've paid particular attention to these species in the last few years and am often struck by how different the pale clouded yellows (the less common of the two near me in Switzerland) are. Where ecological and behavioural clues have been able to support my identifications, they have always been right. Pale clouded yellows have proportionately slightly longer forewings (compared to the hindwings) and at rest look markedly more 'raked'. Berger's look rounder and squatter. This is definitely something that comes with practice, but I have (rather casually so far) been taking measurements and will see if I can come up with something statistically significant. Although you can't take absolute measurements in the field or from a photo, you can measure proportions from a perfectly flat-on side view.

It is probable all the differences (wing shape, brightness and size of the orange spot, extent of black shading along the inner margin) are only statistical indicators, and none is conclusive. But when all combine in the same individual you can have a fairly strong presumption. Couple this with ecology/behaviour and you can feel confident in a large number of cases.

Guy

PS - Here is hyale in its typical habitat of a clover field:

padfield wrote:It's interesting neither of the rarer clouded yellows seemed to make it to the UK this year, when clouded yellows were so common. Who knows what surprises 2014 will bring - a few Berger's clouded yellows would certainly be a treat, though there would be a lot of ID queries in the pages of UK Butterflies, I think!

This one is a male, in a meadow near me:



Guy

I wonder what the chances of Berger's establishing in southern England are - it is apparently common on the chalk in eastern Normandy, and warming temperatures should make its establishment in Sussex or Kent a possibility.

Maximus wrote:I saw lots of Clouded Yellows in the UK in 2103, but I saw this Berger's Clouded Yellow in the Dordogne in July 2012.

Berger's CY.jpg

The spotting on the underwings of this butterfly seem very dark and intense, compared with the other butterflies on this thread. Is this within the normal range of variation?

Matsukaze wrote:I wonder what the chances of Berger's establishing in southern England are - it is apparently common on the chalk in eastern Normandy, and warming temperatures should make its establishment in Sussex or Kent a possibility.

Interesting thought! Even though it is a more southerly species than pale clouded, its sedentary character, and the fact its preferred habitats are some of the best protected habitats in the UK, suggest it might be a more stable resident than its cousin if it ever did gain a foothold. In Switzerland, you are sure to find Berger's anywhere you find Adonis blues and chalkhill blues.

Guy

O.K. guys,what would you say this is.It was seen in the Brenne 2yrs ago,with Adonis and Chalkhill blues,on a chalky slope.
P.J.U.
P.S. I'm finding this a fascinating thread,because it shows how difficult it is when the question is thrust upon you in a different environment.