How long do dragonflies live?
And why should you care? Eleanor Colver of the British Dragonfly Society lists the reasons
The question “How long do dragonflies live?” plagues me (among many other things). Let me explain why.
I’ve said it a few times, and I’ll say it again. I used to see a lot of dragonflies almost every day when I was younger; now I barely see any that I feel like celebrating and throwing a party whenever I find one in the garden.
Did I miss something? Why aren’t they around anymore? Why are they so few? Do they die early? Is it because their lifespan isn’t that long to begin with?
Unfortunately, the dragonfly’s absence is felt in other places. In fact, UK dragonflies are in trouble too. But the good news is they have the British Dragonfly Society (BDS) to help them survive and come through.
“This year the British Dragonfly Society celebrates its 40th birthday and four decades of championing the protection of dragonflies and their wetland habitats,” says Eleanor Colver, British Dragonfly Society conservation officer.
The non-profit organisation is responsible for running the national recording scheme for dragonflies in Britain, she adds; plus it provides guidance in wetland habitat management and species conservation, and works to raise awareness through outreach projects and events.
You can thank their volunteers for that. “Our work could not be achieved without the support of our country-wide network of volunteers, and there are many volunteer opportunities available to get involved, including recording, habitat management and outreach,” she reveals.
“You can find out how to get involved here.”
So how long do dragonflies live?
Let’s get right to it.
“Lifespan varies from species to species,” Ellie begins. And their life cycle is as follows:
#1 Eggs
“All species start their life cycle out as eggs, which are either laid directly into freshwater or inserted into plant material in or near to water.
“Depending on when the eggs are laid, they will then come out after a few weeks, or will over winter until the next spring.”
#2 Carnivorous aquatic larvae
“The next stage in the life cycle is carnivorous aquatic larvae. They spend, on average, one to three years in this stage underwater, feeding off other small creatures like midge larvae.
“Once the larvae have fully matured, they crawl out of the water and undergo emergence, shedding their hard-out exoskeleton and revealing their flying adult form.
“Unfortunately, the adult stage is much shorter, usually just a few weeks.”
So when a dragonfly visits you, consider yourself lucky
I would. We’ve already established that I do.
With this post, I hope you soon will too.
“Dragonflies are a beautiful and fascinating group of insects,” Ellie relates.
“Their vibrant colours and aerial prowess make them a delight to watch. I can (and do!) spend hours sitting by a pond watching males fight over territory and females egg-laying.”
I don’t have a pond nearby, so I haven’t had the pleasure of doing that. But instead of finding one on short notice or visiting the UK, I can just ask Ellie: How are UK dragonflies doing right now? Would it be too late for dragonflies that I wouldn’t have the chance to observe them like that?
“Dragonflies in the UK are undergoing rapid change,” she tells us. Here’s why.
#1 UK dragonfly statistics
“The current British and Irish list of damselflies and dragonflies (Odonata) comprises 56 species, of which 46 are residents or regular migrants; a further 10 species have occurred as rare vagrants,” she explains.
“Nineteen of our resident and/or regular migrant species (41 per cent) have significantly increased in occupancy since 1970, while five (11 per cent) have shown significant declines overall. Occupancy is measured as the proportion of the geographical area in which a species was present in each year.
“In addition, six species have colonised Britain since 1996, while a seventh has recolonised after an absence of almost 60 years.”
#2 Environmental issues
“Climate change in the form of increased temperatures is behind many of the positive dragonfly species trends and new colonisations, allowing historically southern species to spread north,” she notes.
“Increases in the availability of suitable habitats through restoration and creation have also played a significant role. However, it must be noted that an increase in a species’ occupancy does not necessarily mean an increase in abundance.
“Habitat loss and degradation through land drainage, afforestation and lack of appropriate management are likely to be major factors in species decline, along with changes in weather patterns, causing both flood and drought conditions.”
#3 Humans and human activity play a role in a dragonfly’s survival, and the chances of it thriving
“Unfortunately, humans have not been kind to dragonflies in the past,” Ellie says.
“In the UK, over the past 100 years or so, we have lost 90 per cent of our wetland habitats. This has mostly been a result of draining wetlands to make room for agriculture, new settlements and forestry.
“Many of our surviving wetlands are not in good condition and are negatively impacted by pollution, poor management and invasive species like signal crayfish (Pacifastacus leniusculus), a voracious predator of dragonflies,” she also points out.
“For example, less than 20 per cent of England’s water bodies have a good ecological status. However, there are plenty of organisations and charities working to restore and improve our waters, with the help of the public. There’s the Four Rivers for LIFE Project in Wales that is currently underway to protect, enhance and help restore over 500km of the Rivers Teifi, Tywi, Cleddau and Usk. This will include restoring woodland along riverbanks, invasive species control and working with landowners to reduce pollution.”
How can we help dragonflies then?
If you want to do your part, Ellie shares her top tips:
#1 Learn more about dragonflies
“This is one of the best things you can do. Learn the value of their wetland homes and the threats they face.”
#2 Share your new interest with others
“For example, take your friends or family to see your favourite dragonfly site. The more people there are in the world who care about dragonflies, the brighter their future will be.”
#3 Volunteer
We can’t stress this enough. “For volunteer opportunities such as recording projects, and to get involved in events, please visit the BDS website. We participate in a range of activities from field meetings to family bio-blitzes every year.”
#4 Rethink your outdoor space
“Thirty per cent of the urban landscape of Britain is made up of residential gardens, which have the potential to become havens for dragonflies and other insects – so the best way to attract dragonflies to your garden is by adding a pond for them to breed in,” Ellie suggests.
“The best dragonfly ponds are rainwater-fed, fish-free and full of a variety of native wetland plants. If you don’t have room for a pond, you can still create an excellent habitat for foraging adult dragonflies by ditching pesticides, leaving areas of long grass and planting native wildflowers. This will increase the amount of pollinators in your garden, such as butterflies and hoverflies, creating a buffet for hungry dragonflies.”
For gardening advice, Ellie urges us to check the BDS website.
#5 Get in touch with your local officials
“Many of the threats facing dragonflies and their habitats are the same threats shared by many other species in the UK. This includes climate change, pollution and habitat destruction,” she cites.
“These issues need legislative change and investment on a national level. You can share your concerns with others, including your MP, as it is their job to represent the interests of their constituents in Parliament. You can find guidance on how to do so here.
“You can also support the work of charities, such as the BDS, through donations and membership, as they work to raise awareness and tackle these threats to our precious wetlands. Learn more here.”
Ellie’s favourite projects and experiences with the British Dragonfly Society might also help to convince you.
“My favourite part of my job at the BDS is travelling to different sites to help other organisations and volunteer groups with their dragonfly-related activities, whether it’s setting up monitoring projects or putting together habitat management plans,” she admits.
“One example was helping the volunteers at Willington Wetlands Wildlife Trust site, Derbyshire, set up a dragonfly monitoring project so they could assess how the site’s dragonfly population reacted to the reintroduction of beavers on site. Apart from enjoying an excuse to get outdoors and watch dragonflies, it is always wonderful to meet other people with a passion for wildlife and have a chance to learn from one another.”
So how about it? If we’ve managed to spark your interest in dragonflies, you can find the British Dragonfly Society here and on Facebook, Twitter and Instagram.
Facts about dragonflies
Now we come to the fun part. (At least I think it’s the fun part.)
I know not a lot of people understand my dragonfly obsession (and think it’s weird). But maybe this information from Ellie will finally get you onboard, and have you realise just how fascinating they are.
#1 Dragonflies have been around for over 300 million years, way before the dinosaurs
“The early ancestors of our modern-day dragonflies included the giant Meganisoptera, also known as griffinflies, which had a wingspan of up to 72cm,” Ellie states.
“Dragonflies are now considered the most successful predators on the planet and catch 95 per cent of the prey they target. Despite their size and simple nervous system, they are able to project the trajectory of flying prey in order to intercept it.”
#2 What do dragonflies eat?
Ellie mentioned earlier that they eat midge larvae, butterflies and hoverflies, among others. But dragonflies do affect the health of an ecosystem with their diets and very existence.
“Dragonflies play an important role in our wetland ecosystems here in the UK, both as predators feeding on small flying insects and as prey, particularly for birds – emerging dragonflies are a valuable source of protein for chicks in spring.”
#3 There’s a difference between a dragonfly and a damselfly
“At the British Dragonfly Society, we are interested in the study and protection of the insect order Odonata, which is referred to as dragonflies,” Ellie says.
“This order includes Zygoptera (damselflies) and Anisoptera (‘true’ dragonflies). These two groups are easy to tell apart when you know how.”
This quick dragonfly vs damselfly comparison from Ellie will help.
Dragonfly vs damselfly
Dragonflies have:
• A chunkier body
• Large eyes that usually touch at the top of the head
• Hindwings that are wider than their forewings
• Wings that are usually held fully outspread when at rest
• A powerful flight
Damselflies have:
• A more delicate body
• Smaller eyes that are far apart on the head
• Wings that are all the same shape and held closed, or partially closed, along their back when at rest
• A weaker flight
#4 There are a number of factors that affect a dragonfly’s life and lifespan
• Food and climate
“Limited food availability and cold conditions can slow larval development,” Ellie observes.
“The golden-ringed dragonfly (Cordulegaster boltonii) is our longest-living dragonfly in Britain. Its larvae are found in acidic rivers and streams in heathland or woodland, often in upland areas like Snowdonia National Park. These wetland habitats are often cooler and support less prey; as a result, its larvae may take five years to fully develop.”
• Predators
“Predation can also cut a dragonfly’s life short,” she continues.
“The main predators of their larvae are fish, large invertebrates like water beetles, and amphibians. Adults are fast and agile fliers and have superb eyesight, making them difficult to catch.
“Damselflies, however, can fall prey to spiders while main predators of the larger, faster dragonflies are birds, especially Hobby, which specialises in feeding on dragonflies.”
• Specific life stages
“Dragonflies are most vulnerable during emergence, when they are in the process of transforming into an adult,” she says.
“During this period, they are immobile and it takes a while for their new body and wings to harden. As a result, they can easily be picked off by predators, or knocked into the water by wind and rain.”
#5 There are myths and misconceptions about dragonflies out there
And they can be weird. I got Ellie to help clear some of them.
• Can dragonflies walk?
“I’m not sure where this myth of dragonflies having weak legs has come from – they are actually very strong as they need to be able to wrestle prey. You won’t see an adult dragonfly walking long distances – they have wings for that! However, you will see them shuffling around to survey their surroundings and find suitable egg-laying sites.”
• Does a dragonfly bite?
“Dragonflies will only bite you if you deserve it; for example, if you manhandle one. They do, however, feast on other biting insects, including midges, mosquitoes and horse flies.”
• Do dragonflies sting?
“Dragonflies don’t have stings, despite historically being referred to as ‘horse-stingers’. The females of some species have ovipositors, which look like stings but these are used for laying eggs.”
• How many colours of a dragonfly are there?
Because I’ve seen some incredible ones: bright orange, sapphire blue, brown, red and even green, I think, and they’re mixed with other hues.
“Dragonflies come in an amazing range of colours and have magnificent patterns. Males and females often vary in colour too,” Ellie says.
“Dragonflies have excellent colour vision, much better than humans, and this variation in appearance helps them identify individuals of the same species and their sex.
“In some damselflies, females come in different colour forms. Blue-tailed damselflies (Ischnura elegans) are one of my favourite species because of this; their females can be blue, green, pink, purple or a yellowy brown, and change colour with age.”
I think I can handle the “How long do dragonflies live?” question better now.