Wednesday, January 6, 2016

Happy New Year!

A heatwave throughout July and August last year had a notable effect on the emperors. I didn't find a single egg and only in September, when the forest verges were cut, was able to locate any caterpillars - just two, both deep in shade and near the ground, presumably where the air was most humid. I can only hope it was choice of laying site that meant I found no eggs in the usual places. I followed just one caterpillar, Gautama, up to hibernation, when he wandered off. I couldn't find him anywhere. Then suddenly today, on my first Swiss walk of 2016, there he was, not 20cm from the leaf he grew up on.

Gautama:


Happy New Year!

Guy

7 comments:

irisscientist said...

Greened up and read to feed I see. I see that the leaf buds are also ready to pop where you are also. Worrying times ahead if colder weather suddenly kicks in. Even my limited number of naturally diapaused 2nd generation specimens have now woken up and want to feed. The majority of my 2nd generation and none of 3rd generation diapaused at all. I am now working on the 4th generation this season. I've now had active larval specimens continually on the go for around 10 months. Simply crazy.

Guy said...

Cold weather will kick in - Gautama is at 1000m in the Alps. But for the time being, primroses and cowslips are in flower and though it has rained for the last few days it is really quite warm. I've been following your posts with interest. You have a little control, at least, over your protégés - I just have to hope that nature has armed the wild caterpillars with the best responses to this abnormal (but not unprecedented) weather. I'll post updates when there is something to report.

Guy

irisscientist said...

Guy. Much more info, photos and regular project updates are posted on my Facebook profile:

https://www.facebook.com/irisscientist

Matthew Oates said...

Disagree, that's not ready-to-feed green - which is a brighter, pure green. Guy's is how the yellow-green hibernating variety (one of three main winter colour forms) looks in sunshine.

In the mild winter of 2013-14 I followed a couple which never changed colour but remained bright green - they got through the winter, only to get crunched in early spring.

Any ideas why the egg lay was so poor in Switzerland, Guy?

irisscientist said...
This comment has been removed by the author.
Guy said...

"Any ideas why the egg lay was so poor in Switzerland, Guy? "

We had a serious heatwave in July and August, Matthew. Searing sun and virtually no rain. My theory is that eggs were laidin denser parts of the forest and closer to the ground, where there would be more humidity. My only evidence to support this is that when they cut the verges I found two caterpillars (the only two I found) on low branches, less than a metre from the ground, where they would have been completely hidden by the tall grass. Perhaps all over the forest there were caterpillars secreted in dank places, now hibernating a little higher up and ready to reach for the lighter heights next year.

I hope so ...

Guy

Matthew Oates said...

I've studied them in heatwaves here - notably in 1976, 2006 and 2013. In heatwave conditions they lay in deep shade, where thinner, greener leaves occur. The egg lays of 76 and 2013 were monumental here (I don't have such good data on 06).

I'll put out some news on winter hibernation success soon. Fingers' crossed, but things are looking goodish. Watch this space...