What do the Maldives and dragonflies have in common?
Well, not a lot, seeing as how there is no surface water to speak of in the Maldives, and dragonflies need it in which to breed. Yet every year in October, Maldives resident and naturalist Charles Anderson started to take note of the fact that swarms of dragonflies were suddenly appearing, staying for a couple of months, then vanishing again just as quickly. At first he didn’t think too much of it, but when he started thinking about their fresh water dependence, he realised something strange was going on, so decided to investigate further.
Talking to colleagues in mainland India, he realised that the dragonflies – these are a specific species known as the Wandering Glider or Globe-Skimmer – weren’t just coming across to the Maldives to die, so something else must be going on. Spreading his net of informants a bit further afield, he started getting information that the dragonflies were being seen a few weeks later in East Africa, having travelled a couple of thousand kilometres across open ocean.
Incredibly, the Wandering Gliders were riding the front between the monsoon seasons, travelling at around 2000 metres in altitude, tracking the rains to East Africa where they would breed.
But the story (and the journey) didn’t end there…
Most mosquitoes have a larvae-dominant lifestyle; that is the larval or nymph period takes about 10-11 months (but can be up to four years!) and the adult stage only one or two months. The adults don’t have a lot of time in which to breed before they die.
In the case of the Wandering Glider however, things are quite different. Nymphs only have about six weeks to develop into adults, then they have to be up and off again, looking to breed, following the rains. From East Africa, they don’t go back to India though. The winds are against them by this time, and the dry season has settled in on the Asian sub-continent. Instead, the second generation of dragonflies continues south, following the winds, which are necessarily moving in towards the next rains, which are falling in Southern Africa.
Once in Southern Africa – hopefully we see a few of them at Londolozi this summer – another breeding bout takes place, and generation #3 emerges. By now the season is changing, and the population does a 180. They fly back north, retracing their steps to East Africa, where they breed yet again, and the fourth and final generation emerges for the flight back across the ocean back to India, where the cycle begins anew.
16 000 kilometres (10 000 miles) is the total distance flown in four generations of dragonfly over the course of a year; a truly remarkable migration! It was previously thought that the Monarch Butterfly undertook the longest migration of any insect (just under 10 000 km for the round-trip), but the Wandering Gliders wipe the floor with the Monarchs!
Riding the same air currents, and at similar altitudes, come a host of insectivorous migrational birds as well. Amur Falcons, European rollers and Blue-cheeked bee-eaters will all be flooding south, snacking on a number of dragonflies as they go.
We always make a big deal of bird migrations (which we should, as they’re pretty phenomenal as well) but I always used to try make them seem that much more hardcore by saying they didn’t have the benefit of the in-flight meal. Well, if they’re cruising along in the midst of a few million Wandering Gliders, maybe they do after all…
Birds, insane dragonflies, emerging dung beetles, impala lambs… the joys of summer are almost upon us. I just know that this year I’m going to be making a much bigger deal out of the Wandering Gliders than I have have before!
This is interesting. Amazing that a tiny insect fly from one continent to another. Summer is upon us. I saw the first Christmas beetle this weekend. All we need now is rain.
Definitely need rain Marinda, the bush is looking exceptionally dry!
here in our pond the emperor dragonfly lay her eggs and it is after 2 years they say that the nymph comes out of the water ,opens and the new dragonfly “sleeps” out .
I have been watching it for a few hours before the wings dry , just like with a butterfly .I think I posted some pictures of it on instagram
How awesome are these Wandering Gilders. Thanks James for highlighting them. So many fabulous facts about these and so many others species.
You’re welcome. Yup, everything here is amazing if you look a little deeper!
Fascinating James! I think nature will teach us, if we sit, observe & be quiet..
I couldn’t agree more, Gawie!
James, I did not know about the Wandering Gliders. Great blog today!
Thanks Joan!
Quite an amazing tale, James! We saw swarms of dragonflies recently while in SE Asia – cousins of the gliders maybe?!
Quite possibly! Maybe even the same species. What time of year was it?
Just two weeks ago…
This is an almost unbelievable story, James. Incredible little insects they are! I am always amazed hearing the stories of the birds which emigrate too of course. Quite incredible. But this is the most incredible of the lot for me, so far! Thank you so much for this! I am going to pass it on to friends / relatives, anyone who is interested. Wendy M
Hi Wendy,
Definitely share with people. It’s an incredible story about these little things…
James, this blog was absolutely fascinating! Who would have thought this little insect has such an interesting back story. Thank you for educating us a bit more
You’re welcome Denise!
Another marvelously surprising story … thank you James!
What a fantastic post. Thank you
Very cool story James! We never thought about how insects can take advantage of the higher altitude winds! Thanks for another wildlife lesson!
Dragonflies are such fascinating insects. I see them often in the Pacific NW where I live but didn’t know much about them or their migration to other locations. The Wandering Glider is beautiful as is the European Roller. The feast and the one who feasts. Such is the balance of nature. Great article and images.
What a totally facinating story, James! Really. I learned so much and will have to re-read this again to let it all sink in. What incredible cycle for such a little insect! Thanks James for bringing an excellent and interesting story to me. Your scope of writing is so diverse.
Interesting post!!