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.
Delighted to report that all six larvae I've been following in the wild survived December, and were present and correct on Jan 1st (there may be one or two more which I haven't yet located in hibernation). This is good news as tit predation tends to be high during mild winter weather, and low during severe cold - but perhaps larvae were protected to some extent by December's excessive rain.
It appears that tit predation is relatively low in years when larvae are scarce, as is the case now.
Interesting that two of the six had moved position, one by a staggering 2m. This tallies with mass movement recorded during the mild December of 2013, when I was following a much larger number of larvae. However, none of the larvae which woke up and moved during the 2013-14 winter actually survived into the spring.
Here are some photos from today:-
This one has stayed put, and is close to swelling green buds.
The one above has moved to a shady position up stem, in a lesion, from a terminal leaf bud exposed to sun. My guess is that it might move again.
There were two here, head to head, but one (No 14, below) moved 2m to a leader bud.
Interesting that this larva was grey-green but has changed colour to match its new background.
This one's a cracker, grey on grey. It's unusual to find one on dead wood.
Finally, here's one in a classic position. We are seriously overdue a good summer, and this year is 40 years on from the long hot summer of 1976, the ultimate butterfly summer of modern times. The last good summer we had was ten years ago, in 2006 - 30 years on from the long hot summer. So, jack in the job, sell the children into slavery, send the spouse off to the mother-in-law's and go Emperoring - the long hot summer's returning...