What dragonflies say about our ignorance of the natural world


Klaas-Douwe B. Dijkstra, Stellenbosch University

Of the 8.7 million species of animals, plants and fungi thought to live on Earth, we have only named 1.2 million: 86% of the natural world is uncharted.

For most people, both this incredible richness and our ignorance are hard to fathom. Imagine that each of the 6.5 million species thought to live on land – the rest is marine – had an equal share of it. Each species’ plot – also that of the human species – would cover an area only one-quarter the size of Manhattan. Expressed this way, we as humans have not just far overstepped our bounds, but mapped only the equivalent of Europe, India and China, which make up about 14% of global land surface.

What’s worse, the habits and status of only 80,000 species are known well enough to really assess our impact on them. Of those, 29% risk extinction. So, returning to the metaphor, the species that we’re actually familiar with equal only the combined area of Spain, France and Turkey. And if 29% of all species died out, that would equate to the entire New World voided of life.

In other words: while we’ve had an apocalyptic impact on the biosphere already, it has been charted as well today as the globe was in Columbus’s day. This matters because knowing other species can provide a moral counterweight to life’s runaway exploitation: intact biodiversity is the undeniable proof that humans can inhabit Earth without destroying it.

That’s why naming species is important. Names harness the power of recognition. They acknowledge the other exists. They introduce familiarity. As someone once exclaimed to me, “you don’t notice species until you know they can have a name!”

In an era of extinction, there are no greater priorities than to uncover our millions of cohabitants and to share our knowledge of these species. This can be done through research, books, websites, Red Lists of threatened species, field courses, teaching materials and other media. But while every human relies on this knowledge, even if only by reaping the benefits of agriculture and medicine, few see its advance as their primary responsibility.

Few animals can raise that moral awareness of biodiversity better than dragonflies, literally rising from healthy freshwaters in colour and splendour.

Breaking the anonymity trap

Most of what is unknown is not just unseen, but not even being looked for.

There are 6,000 named dragonfly and damselfly species worldwide. These charismatic aquatic insects are regarded as well-known. But last December we published 60 new species in one article. This added one species to every 12 known ones in Africa.

Known from only one site near Cape Town, the endangered damselfly Spesbona angusta needs all the ‘Good Hope’ (Spes Bona in Latin) it can get.
Copyright Jens Kipping

Of course these species existed already, but were not noticed and documented before. Most unknown species may seem indistinct or concealed, requiring meticulous lab-work to uncover, but the 60 were found in accessible places all over Africa and are often recognisable even from a photo.

This May, English nature broadcaster Sir David Attenborough was given a new dragonfly species from Madagascar for his 90th birthday. In the scientific journal Nature I explain that both the dragonfly and Attenborough’s legacy stand for a selfless and unconditional love of nature.

I am often asked what the “use” of dragonflies is. They are not studied because they are not proxies of human psyche and society like ants and apes. They are not feared and persecuted like mosquitoes and snakes. They do not feed people like fish, nor pollinate crops like bees.

Rather, the beauty and sensitivity of these creatures – and so many others – stand for the state and needs of nature before our own. Like the instant sense of insignificance when counting stars, biodiversity stretches our perspective on life. Each species is a world parallel to our own, evoking a sense of being among equals.

What’s in a name

If species embody sustainability and names give them faces, those tags best be memorable. The sparklewing damselfly Umma gumma, named for the rock band Pink Floyd’s album “Ummagumma” (slang for making love), is a special favourite. The longleg dragonflies Notogomphus kimpavita and N. gorilla were named for the patron saint and conservation flagship of their Angolan and Ugandan regions respectively.

But who is out discovering species and introducing them to mankind? Nature is held hostage by humanity’s growing demands and so conservationists barely have time to find out who they really work for. Environmental consultancy is captive to the market. Many biologists have retreated into the lab. Without funds for discovery and disclosure, even natural history museums are giving up.

Only nine of our 60 new dragonflies were found while one of us worked for a university or museum. The other 33 were found while doing consultancy and 18 were found by a teacher. Much of the best biodiversity research and outreach now comes from devoted amateurs and academics working in their free time, showing how close biodiversity is to the human heart.

In a society governed by money, charity is what we do for others for free. But just as we cannot expect volunteers to protect the environment or eradicate poverty alone, we cannot continue life’s elementary and enlightening exploration without support. Nature needs more explorers.

The Conversation

Klaas-Douwe B. Dijkstra, Honorary research associate Naturalis Biodiversity Center and, Stellenbosch University

This article was originally published on The Conversation. Read the original article.

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The role of climate change in eastern Australia’s wild storms


Acacia Pepler, UNSW Australia

Australia’s east coast is recovering from a weekend of wild winds, waves and flooding, caused by a weather pattern known as an East Coast Low. Tragically, several people have died in flooding.

Parts of New South Wales have received more than 400mm of rain since Friday morning. Some places such as Canberra and Forster recorded their wettest June day on record. Waves have also caused severe coastal erosion and damaged property.

East Coast Lows are a type of low-pressure system or cyclone that occur on the Australian east coast. They are not uncommon, with about seven to eight lows a year causing widespread rainfall along the east coast, particularly during late autumn and winter. An East Coast Low in April last year caused similar damage.

But whenever they happen they raise the question: did climate change play a role?

Good news?

Climate models suggest that the cyclones that move through the global mid-latitudes, around 30° to 50°S, are moving south. This is contributing to long-term declines in winter rainfall in southwestern Australia and parts of southeast Australia.

These models also suggest that the atmospheric conditions that help East Coast Lows form could decline by between 25% and 40% by the end of the century.

In recent work, my colleagues and I looked even more closely at how climate change will affect individual East Coast Lows.

Our results also found East Coast Lows are expected to become less frequent during the cool months May-October, which is when they currently happen most often.

But there is no clear picture of what will happen during the warm season. Some models even suggest East Coast Lows may become more frequent in the warmer months.

And increases are most likely for lows right next to the east coast – just the ones that have the biggest impacts where people live.

This chart shows how the frequency of East Coast Lows could change by 2080 across May-October (left) and November-April (right). Red indicates fewer storms, while blue indicates more. Crosses show high agreement between climate models.

What about the big ones?

The results in the studies I talked about above are for all low-pressure systems near the coast – about 22 per year, on average.

But it’s the really severe ones that people want to know about, like the current event, or the storm that grounded tanker Pasha Bulker in Newcastle in June 2007.

These storms are much rarer, which makes it harder to figure out what will happen in the future. Most of the models we looked at had no significant change projected in the intensity of the most severe East Coast Low each year.

Warming oceans provide more moisture, so intense rainfall is expected to increase by about 7% for each degree of global warming. East Coast Lows are no different – even during the winter, when East Coast Lows are expected to become less frequent, the frequency of East Coast Lows with heavy rain is likely to increase.

Finally, even though there may be fewer East Coast Lows, they are occurring in an environment with higher sea levels. This means that many more properties are vulnerable to storm surges and the impact of a given storm surge is that much worse.

Was it climate change?

While the frequency of cool-season East Coast Lows looks likely to decrease in the future, changes in the big ones are a lot less certain.

However, East Coast Lows are very variable in frequency and hard to predict. So far, there hasn’t been any clear trend in the last 50 years, although East Coast Lows may have been more frequent in the past.

As for extreme rainfall, studies have found little influence of climate change on Australian extreme rainfall so far. Climate variability, such as El Niño, currently plays a much larger role. This doesn’t mean climate change is having no effect; it just means it’s hard to tell what impact a warming world is having at this stage.

So did climate change cause this weekend’s storms? No: these events, including intense ones, often occur at this time of year.

But it is harder to rule out climate change having any influence at all. For instance, what is the impact of higher sea levels on storm surges? And how much have record-warm sea temperatures contributed to rainfall and storm intensity?

We know that these factors will become more important as the climate system warms further – so as the clean-up begins, we should keep an eye on the future.

The Conversation

Acacia Pepler, PhD student, UNSW Australia

This article was originally published on The Conversation. Read the original article.