- A global assessment of more than 6,000 dragonfly and damselfly species shows that 16% are at risk of extinction.
- The main threats to these insects are the human destruction of their wetland habitats, water pollution, and climate change.
- There are more dragonfly and damselfly species than there are mammals, yet they remain so understudied that the assessment failed to come up with enough data to determine a conservation status for more than 1,700 species.
- Researchers say better protecting the world’s wetlands would not only save the thousands of dragonflies and damselflies, but innumerable other species too, and provide us with better water quality and more carbon sequestration.
“The coming of autumn
determined
by a red dragonfly.”
– Kaya Shirao
Dragonflies, as depicted in this haiku, have held a special place in Japanese culture for millennia; so much so that among the country’s names is Akitsushmi, or Dragonfly Island. As well as being deemed a harbinger of autumn, these insects symbolize happiness, strength, courage and success in Japan, while the island nation’s art has often portrayed them frolicking around ponds, cheerful and lively. Other cultures variously hold up dragonflies as symbols of good or evil.
But no matter the cultural differences, these beautiful insects with their crepe-like translucent wings and protruding bulb-like eyes reflecting myriad colors are in trouble, researchers say. In the first global assessment of dragonflies and their closely related cousins, the damselflies, scientists found that their numbers are in decline worldwide, largely due to the destruction of wetlands. In total, the assessment found that about 16% of 6,016 species of dragonflies and damselflies, making up the taxonomic order Odonata, are at risk of extinction.
Including nearly every known species of this insect group, the assessment was part of the latest update to the IUCN Red List of Threatened Species, a periodic update of the global conservation status of animals, plants and fungi. The assessment classified 95 dragonflies and damselflies as critically endangered, 298 as endangered and 282 as vulnerable — the three “threatened” categories — and 221 as near threatened.
The researchers also deemed 29% of the assessed species (1,730 species) as data deficient, meaning there wasn’t enough information to assign a conservation status.
The numbers for dragonflies and damselflies echo what’s happening to insects around the world. More than a quarter of all insects are currently threatened with extinction, according to the IUCN.
“This work is significant, especially during a period where we are seeing dramatic insect decline, as it establishes baseline data for the over 6,000 species,” says Jessica L. Ware, associate curator of invertebrate zoology at the American Museum of Natural History. “This assessment is one of many vital steps researchers will be undertaking over the next [few] years as we work to better understand both long term evolutionary patterns and recent impacts of climate change.”
Worldwide, dragonfly researchers like Ware will now be able to use the rich and broad data collected by the IUCN to further their work and expand their public outreach.
Human destruction of marshes and wetlands, which have a history of being seen as “wastelands” despite their ecological value, is the primary cause of population declines among dragonflies and damselflies. Wetlands are ecological powerhouses: they store carbon, protect us from floods, and supply clean water and food.
“Most [dragonfly and damselfly] species live in pristine tropical forests, which have been destroyed to [a] large extent over the last [few] years,” says Viola Clausnitzer, co-chair of the IUCN’s Dragonfly Specialist Group, a global network of scientists and conservationists. “The destruction is still going on for settlements, large-scale and small-scale farming, wood harvesting and logging.”
About a quarter of dragonflies and damselflies are threatened in South and Southeast Asia, which also has the highest global diversity of the flying insects, according to the IUCN. Experts blame this on the razing of wetlands and rainforests for agriculture and urbanization. In South and Central America, similar destruction of rainforests for urbanization has led to declines in these insect numbers. Pesticides, pollution and climate change are the biggest threats in North America and Europe.
The assessment also declared one species as extinct: the St. Helena darter (Sympetrum dilatatum). Last recorded in 1963, this dragonfly was found only on St. Helena, a tiny volcanic island in the South Atlantic Ocean. Since colonizers first set foot on the island in the 16th century, they have destroyed much of its habitat and introduced many invasive aquatic species that drove this dragonfly to extinction.
Guardians of wetlands
Humans are destroying wetlands three times faster than forests, putting dragonflies and damselflies, as well as many other species, in dire peril. Although often an afterthought even in conservation, wetlands house one in 10 of the world’s species.
“[Dragonflies and damselflies] can be used to monitor wetland quality and health, and to serve as sentinels for wetland conservation,” Clausnitzer says.
Any changes to these habitats, or their water quality, affects these insects. Factors like water temperature, acidity, turbidity, or pollution can dramatically upset the survival of the young insect larvae.
These insects also play a vital role as nature’s pest control, according to researchers, as they are the top tiny predators in wetlands. Voracious dragonfly and damselfly larvae feast on disease-causing mosquitoes, midges, and flies before they grow into adults.
Dragonflies and damselflies are fascinating insects for another reason: they were among the first flying animals.
“Birds, bats and pterosaurs took to the skies long after the first fliers, which were the ancestors to modern insects that likely looked very much like dragonflies,” Ware says.
It’s the diversity of these insects — their size, shape, color and behavior — that piqued Ware’s interest to study them for the rest of her life. “There are many unanswered questions about their biology,” she adds.
The need for conservation
A number of scientists have recently warned of an “insect apocalypse,” based on declines in insect abundance in many parts of the world. But the majority of the world’s insects haven’t even been described by scientists. Researchers estimate there are 4.5 million species of critters that we know nothing about. It’s no surprise that entomologists are adding new species each year. Between 2000 and 2009, they added 88,598 species — that’s more than 8,000 per year on average. That’s true for dragonflies and damselflies too: in 2016 alone, scientists described 60 new species just from Africa.
“There are more dragonfly and damselfly species than there are mammals,” Ware says. “We know a lot about the differences between hippos and cats and giraffes, and we should take the time to learn more about the variation between different types of dragonflies and damselflies too.” The fact that scientists classified 1,730 species of dragonflies and damselflies as data deficient, despite being a ubiquitous and well-recognized group of insects, points to this knowledge gap.
So, how do we save our damselflies in distress? “We need to take care of our wetlands in all scales, whether small streams in urban areas, agricultural land or pristine habitats,” Clausnitzer says.
She suggests that wetlands, streams and rivers should have riparian buffer zones — strips of protected land next to freshwater sources that are off-limits to agriculture and construction.
“To conserve these beautiful insects, it is critical that governments, agriculture and industry consider the protection of wetland ecosystems in development projects, for example by protecting key habitats and dedicating space to urban wetlands,” she says.
Pollutants pose another issue, given how highly sensitive these insects are to changes in water quality.
“We should avoid practices that pollute the environment either with pesticides that impact the prey of dragonflies and damselflies or change the quality of the water in which nymphs develop,” Ware says.
“We should avoid practices that pollute the environment either with pesticides that impact the prey of dragonflies and damselflies or change the quality of the water in which nymphs develop,” Ware says.
That also includes preventing sewage, mining, and industrial waste from polluting our streams and rivers. Improving our protections of the world’s wetlands would not only save the thousands of dragonflies and damselflies, but innumerable other species and provide us with better water quality and more carbon sequestration.
Japan, where a quarter of dragonfly species are at risk of extinction, has shown the world how to start protecting these enchanting insects. It has built the world’s first protected area dedicated to dragonfly conservation, called the Shimanto Dragonfly Kingdom, which also houses a museum. Cities like Yokohama have also restored hundreds of dragonfly ponds, where people can admire the gambolling of dragonflies and damselflies:
“Dance, O dragonflies,
In your world
of the setting sun.”
(Unknown poet)
Banner image: The dawn jewel (Chlorocypha aurora) is a critically endangered damselfly from Cameroon. Its habitat is declining due to forest destruction, water pollution and siltation. Image courtesy of Jens Kipping.