Yeah right!!!!!!P.J.Underwood wrote:The paddyfield warbler should be easy tomorrow.

Anyway...back to the butterflies?
Yeah right!!!!!!P.J.Underwood wrote:The paddyfield warbler should be easy tomorrow.
Hopefully, Guy. They were here in large numbers last autumn and the mild winter will have done little to deplete their numbers significantly.padfield wrote:That looks like a gravid female red admiral to me, Mike. If so, perhaps a native spring generation is on the cards...
But it wasn't continually mild in the east. We had quite a cold spell from near the end of January until mid February, yet Red Admirals survived. So It cannot be simply a question of temperature as to whether or not they survive.They were here in large numbers last autumn and the mild winter will have done little to deplete their numbers significantly.
My guess would be that the reverse is true. Hibernation involves switching the metabolism to an absolutely minimal level so long periods can be sustained without using up significant amounts of energy, regardless of the temperature. Merely going torpid, on the other hand, leaves the butterfly at the mercy of the temperature. If the temperature is very low, little energy is used up in respiration and the butterfly can last a long time. If the temperature is (relatively) high, respiration proceeds at a higher rate, sugars are used up and the butterfly risks its batteries running out over the winter.David M wrote:If it's true that they don't go into a true hibernation then I guess it's preferable for them to experience milder temperatures than cold ones.
Yes, I hadn't thought of that before. Brimstones hibernate early which may explain why they're usually out very early - it's too mild from late February onwards to sustain them any longer.padfield wrote:
The deepest hibernators go to bed in July or August and can last until April quite easily. Red admirals are still on the wing into November and December, perhaps because if they 'hibernated' earlier they would not last even until the winter.
Well done, Michael. Not surprising really given that Cardiff got a mention on the BBC weather tonight as today's warmest spot at 16C.Michaeljf wrote:Another post-hibernation butterfly seen at lunchtime today at my local patch in South Wales - a single Comma in the 15c sunshine. Unfortunately it'll be back to the rain by this weekend here, by the look of the forecast.
Still, March starts tomorrow. Difficult to believe it's come round already![]()
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Michael