The case of the Green darner - Anax junius
It is one of the 9 migratory species known in the USA.
Part only of its populations is migratory; those living in the North remain there and reproduce locally whereas in the southern ones move northward to reproduce and the following generation returns then southward, travelling so several hundred kilometers each time - see detailed explanations in Charles Anderson's brilliant video [HERE].
They migrate exclusively by day with winds below 25 k/h, whatever these winds' direction and only after 2 successive nights of low temperatures.
Some years, a few individuals have been seen on Brittany’s coasts in France, carried by high altitude winds but too weak to reproduce.
In the US, the Green darter is the object of a study with a tiny transmitter placed under the abdomen of a few insects. the results are stunning: Some manage to fly 140km / day!
The Red veined darter (Sympetrum fonscolombii) is also quite a traveller:
so is the Four spotted chaser (Libellula quadrimaculata)...
and Hemianax ephippiger, 2011 being an exceptional migration year in France et of which Alain has been a witness:
Finally here is the fascinating case of the Globetrotter (Pantala flavescens), a common species in the tropical regions crossed by the equator, but the species inhabiting the countries around the Indian Ocean have a very particular migratory cycle.
These last years, Charles Anderson (see the video above mentioned), an English marine biologist who has been working in the Maldive Islands for 26 years noted the appearance of million of these dragonflies at a precise moment every year.
He asked his contacts in India if they had been noticed a similar event on the continent at the same dates... The answers confirmed his sightings! Fresh water lacking totally on the Maldive Islands, he wondered why they were flying there.
The Jacobin Cuckoo (Clamator jacobinus),
and the Indian Roller (Coracias benghalensis) among many others