Dragonfly species found to fly 12,000 miles between India and AfricaJuly 21st, 2009 - 5:32 pm ICT by ANI
London, July 21 (ANI): A species of dragonfly flies may hold record for the longest migration of any insect, for an expert says that they fly an amazing 12,000 miles between India and Africa every winter using a tropical weather system.
If it is confirmed, British naturalist Charles Anderson’s theory would mean that Pantala flavescens-which measure no more than 5cm-migrate from southern India to Africa and then back.
“It’s an amazing story. But what is beautiful is that the pieces of the puzzle fit together,” the Independent quoted Anderson as speaking by telephone from his home in Male, capital of the Maldives.
Anderson first started thinking about the dragonflies after he arrived in the Maldives in 1983. Intrigued by their appearance, he began collecting data and maintaining records about the dragonflies’ arrival and departure.
He found that the dragonflies in the Maldives arrived somewhat after similar swarms of the insects appeared in southern India.
On the more southerly atolls of the Maldives, they appeared later still. The numbers peaked in November and December.
If Anderson is to be believed, the dragonflies are heading to southern and east Africa, slowly making their way eastwards on the tradewinds.
According to him, it is in November that the dragonflies appear in the northern Seychelles, around 1,700 miles from India.
In Uganda, he adds, they appear twice a year-in March and April and again in September.
In Mozambique and Tanzania, according to Anderson, they arrive in December.
Writing about his observations in the Journal of Tropical Ecology, Anderson also says that the creatures are making the most of the weather system of the so-called Intertropical Convergence Zone, that moves southwards by way of the Maldives every year.
It follows those winds at a height of more than 3,000 feet, he says.
“Circumstantial evidence suggests that the dragonflies fly with north-easterly tail winds, within and behind the ITCZ,” he writes.
The naturalist even claims to have collected circumstantial evidence to suggest the dragonflies returned to the Maldives in the spring, en route back to Africa.
He reckons that the journey would total around 12,000 miles, and involve the dragonflies passing through four generations.
Anderson said that not only did the dragonflies’ journey make use of rain-providing weather systems that would create temporary pools of fresh water for the larvae to grow, but that the life-cycle of the insect had been modified to allow it to make this journey.
While most dragonflies life-cycles involve a larval stage in which it lives underwater for up to a year, the globe skimmer is able to climb out of the water and metamophosise within just six weeks.
“These guys take a different approach to the typical dragonfly,” he said. (ANI)
Tags: arrival and departure, atolls, british naturalist, charles anderson, circumstantial evidence, dragonflies, dragonfly, east africa, insect, insects, maintaining records, maldives, pieces of the puzzle, southern india, swarms, tail winds, those winds, tradewinds, tropical ecology, tropical weather system