A Field of Frozen Dragonflies
A highlight of the any annual Okavango calendar is the arrival of the flood. Between November and April, huge amounts of rain falls in the highlands of Angola over 1,200km away and, incredibly, 11,000 billion litres of this precious water travels on a slow and arduous journey south to reach the Okavango Delta in the middle of its dry season. Starting at the papyrus and palm-fringed shores of the panhandle, the flood waters spread out into the iconic fan-shape of the Delta, where it is trapped between two ancient tectonic ridges that damn the waters.
An abundance of animals travels in the wake of the flood. Territorial hippos spread out and fight over the best territories. Fish and crocodiles wade with the new waters, finding homes to call their own. Huge herds of lechwe make their way south, splashing through the waters with their perfectly-adapted bodies. As the flood oozes out into the floodplains, they disturb the insects that normally reside there into flight. As they take to the sky, huge flocks of birds are there to feast on the bounty. But they’re not the only ones.
The ferocious African lion’s hunt is successful 25 percent of the time. The elusive leopard, 38%. The African wild dog, 80%. The dragonfly… 90 – 95% of the time! These dainty dangers zone in on a single prey in the crowd, sneaking up on them from behind, and devouring them with their serrated teeth. With four wings that can rotate independently of one another and almost 360 degree vision, dragonflies use their aerial acrobatic abilities to track their flying prey, adjust their path and intercept it precisely, positioning their spiny legs to snare them mid-flight.
Despite being perhaps the most successful predator of the animal planet, dragonflies are still not at the top of the food chain. As they follow the flood in huge swarms, so too do the birds, who do not care to distinguish between a dragonfly and any other insect, and will gobble them up without a second thought. This is particularly problematic during the mornings. The flood arrives at the start of Botswana’s winter and with the abundance of new waters, the temperatures plummet. Dragonflies are cold blooded, so they can’t regulate their body temperatures like we can, leaving them at the mercy of mother nature.
On the morning after the arrival of the flood, we were amazed to find golden floodplains twinkling with thousands of frozen dragonflies. Each individual was perfectly encapsulated in a thin layer of ice, with crystals covering their spiny appendages and enormous multi-faceted eyes. But fret not… as the sun rose, the tiny ice crystals melted, their wings slowly stirred and the fields filled with life as they lifted into the sky in unison. It is perhaps one of the most beautiful things we’ve been lucky enough to see here in Botswana’s Okavango Delta.
The annual flood is what keeps the Okavango alive. Without it, this bountiful oasis would soon turn to dust and its inhabitants lost forever. For its 60,000-year history, these residents have evolved to cope with its precarious cycle. But today, climate change is a very real and present threat. Studies show that dragonflies, like most insects, are particularly vulnerable to change. One particular study that made headlines around the world even suggested that the decorative patterns of a male dragonfly's wing would become such a hindrance in warmer climates that they could evolve to lose it at such a speed that even their mates may no longer even recognise them!
Whatever the models suggest, there is one thing that’s for sure: climate change will make weather patterns, both here and abroad, more unpredictable. Dragonflies are thought to have evolved some 300 million years ago, when the atmosphere’s high oxygen content gave rise to supersize species with wingspans the length of a human arm – if they’ve made it this far, we can be hopeful for the future and, thankfully for dragonflies, as something of an archetypal precision drone, there are plenty of people invested in researching them and keeping them alive (not least the United States military).
That doesn’t, however, mean we can be complacent! It is up to us all to fight this battle. What small step could you take today to lower your carbon footprint?