Camberwell Beauty seen in the New Forest

[John W]

Camberwell Beauty seen by James LeRouge at Hawkshill Inclosure, near Beaulieu in the New Forest today (24th March 2019).

(image taken from Facebook group Butterflies UK)

[Charles Nicol]

thanks for sharing that lovely image John !

Charles

[David M]

I think you'd risk a coronary if you saw one of these in the UK!! I guess, given its location, that it is a captive bred specimen.

[Roger Gibbons]

There have also been three sightings in north London, quite possibly of the same butterfly as the sightings were not far apart geographically, the latest one being seen on 24 March:
http://hertsmiddx-butterflies.org.uk/sightings-new.php

I would suspect that, given the condition of the one John W posted, which seems quite close to pristine, that it may be a release. I would think it would be unlikely to be a migrant at this time of year.

I see quite a lot of Camberwell Beauties in southern Var in April (although noticeably less in recent years) and they usually show a much greater degree of wear than this one, and I would assume that an English winter would take an equal or greater toll on hibernators than a southern French winter.

Roger

[bugboy]

Not sure if I read it somewhere many years ago or have made it up but I've always thought the primary reason for them not being resident in the UK is that our winters are simply not cold enough for them to hibernate properly, so I personally would definitely lean towards captive bred on any springtime sightings.

[millerd]

Having no direct experience whatsoever with this species, my opinion probably doesn't count for much! However...

I have always understood that the pale border bleaches out from a buff creamy yellow to white during hibernation - this one looks near enough white from the image posted. Secondly, the abdomen of this individual looks quite shrunken, as you would expect with a hibernated individual. Thirdly, if captive bred, its natural emergence would be back in the middle of last summer and it would need to have been kept as an adult in artificial hibernation to be released around now. Alternatively, rearing completely out of synch with the seasons might be tricky, as availability of the foodplant in the middle of winter for the caterpillars would be an issue.

No doubt there are counter-arguments to all of this! Of course it could have been captive bred last year and released in the summer to then hibernate naturally.

Dave

[Padfield]

It's true that long, mild winters pose a challenge to Camberwell beauties and that they flourish in cold winters. However, this last winter was short and January at least was rather cold. Any arrivals last autumn would have tried to hibernate and it would not surprise me if some made it through to the end of February, when everything started waking up. Once awoken, Camberwell beauties are long-lived. I have seen spring individuals into July:


(near Domodossola, Italy, 1st July 2016)

Thus, having woken at the end of February, a beauty could easily still be on the wing in late March.

All of which is to say I think this individual is quite compatible with an autumn 2018 arrival.

In my experience, Camberwell beauties hibernate at potential breeding sites. I see the summer brood pretty well anywhere - often cruising over the mountains miles from any sallows. I only ever see spring individuals at sites with water and sallows. If the present butterfly was a natural arrival (or indeed a release last summer), I would expect it to have looked for suitable habitat before hibernating. Is Beaulieu in the New Forest such a site?

I note that 'Beaulieu' rather loosely translates as 'beauty spot'. How appropriate!

Guy

[Roger Gibbons]

Not sure if I read it somewhere many years ago or have made it up but I've always thought the primary reason for them not being resident in the UK is that our winters are simply not cold enough for them to hibernate properly, so I personally would definitely lean towards captive bred on any springtime sightings.

I have heard the same reason, but I find it hard to reconcile that with the fact that they seem to hibernate in the Oak forests of southern France where the winters are decidedly mild - just about to post when I saw Guy's post saying the opposite. Added to that, I have to say that I have never seen a Camberwell Beauty (N. antiopa) in Var anytime after the end of the hibernation period. Lafranchis, in his book La Vie des Papillons, says that most antiopa enter into a diapause in mid-July in this region, which would explain the lack of sightings. What happens after that is not clear. He also says that antiopa is highly migratory and uses thermal currents to assist its flight to high altitudes. Filming Var Wild (https://www.youtube.com/watch?v=WOp6Ea2kcDU) say that antiopa emerges at the end of June in Var and then (immediately?) migrates north. So, do some enter into a diapause and others migrate north?

I have, however, seen a few in the French Alps in July and these have appeared pristine. It may be, based on this empirical evidence, that they travel south to hibernate and that either the hibernators travel north in order to breed, or that they breed in the south and this first generation then heads north immediately. The only evidence I have to suggest the former is the occasional specimen I have seen in the Alps that looks very much as if it had hibernated - one last year at St Dalmas at 1500m which David M will remember. I have also been to sites where several hundred eggs had been found in Var, so clearly egg-laying takes place there, too. It may be that the southern and Alpine populations are entirely separate and have different behaviour. It seems that very little in known about this species.

I certainly concur with Dave that the margins bleach over winter, so any specimen with white borders is almost certainly a hibernator, including the one shown.

I have found that hibernators tend to frequent the same spots each year, with at least some degree of consistency. They tend to remain in these locations for a few weeks. Their flight, even after hibernating, is magnificent, soaring and gliding like no other species.

Roger