I subscribe to the excellent British Wildlife Magazine, I must admit that some of it as a level I neither want or need but there is always something that I find worth reading (and it's nice to get something that doesn't dumb down).
For instance in the wildlife reports there is a piece on dragonfly migration. Dr Charles Anderson (who lives in the Maldives) has discovered that the Globe Skimmer makes regular migrations from India to South East Africa acroos the Indian Ocean. This is a return trip of 14,000-18,000 twice that of the Monarch Butterfly. It takes 4 or 5 generations of dragonfly (I'm not entirely sure if that's both ways). It's possible that the skimmer is using higher altitude winds (1000m+), these can have speeds of 10m/sec making an assisted crossing possible in 24 hours.
A team in the US has put minute tags (1/3 of a gram) on the thorax of the Green Darner (similar size to the European Emeperor Dragonfly). The team followed 14 dragins from a receiving light aircraf and found that the Darner's were capable of flying 137 km per day!
The Darner's final destination is unknown due to the restraints of the small tag size.
Still these two stories given further indication just how much we still have to learn about our word.
3 comments:
Fascinating Pete. Hard to imagine such fragile looking creatures can make such incredible journeys.
Amazing. Thought flutters did well but dragons are travellers too it would seem.
Amazing and you're right,there is so much that we don't know.
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