What the windscreen anecdote tells us about science

The windscreen anecdote has been doing the rounds on social media again.

A couple of years ago, I wrote about why this anecdote is not reliable evidence of insect population trends.

If you’re not familiar with the story, it goes a little something like this. “When I was a kid we would drive long distances for holidays and get bugs all over the windscreen. I don’t see any bugs on the windscreen anymore, therefore….” The interpretation, whether implied or stated explicitly, is that this is yet more evidence that a global insect decline is happening.

There are obvious flaws in this assumption, but the anecdote still strikes a chord with so many people, perhaps through some kind of confirmation bias. We know that biodiversity is in trouble, we know humans are having damaging effects on the environment, so it must be true, right?

Continue reading

Special issue on insect conservation and population trends

The latest issue of Insect Conservation & Diversity is out, a special issue on insect population trends. I’m really happy I was able to contribute to a few papers in this issue as both editor and author (obviously not the same papers in each case!).

Thanks to Editor in Chief Raphael Didham for pulling together a great collection of papers, as well as rallying the editorial team to contribute to the issue with this really useful peer-reviewed paper summarising the key challenges involved in measuring insect population trends. This paper is really timely, as it highlights some of the potential pitfalls involved in estimating population changes over time.

Ecological data (e.g. long-term data on animal population trends) are not like simplified stock market trends or sports team stats. They are confounded by numerous complex environmental and measurement factors, many of which an observer may not be aware of. Nature isn’t simple and we’re kidding ourselves if we want a quick and easy answer to sum up everything, everywhere. Continue reading

Are 40% of insects facing extinction?

This magic number was stated in that flawed entomofauna paper, without any explanation of how this number was calculated – see why that paper is flawed here.

Since then, it has been stated regularly in popular media, scientific papers and technical reports, often without citation, just a number pulled out of the air and presented as fact.

Globally, there are about 5 million estimated insect species in total. Only 1 million species have scientific names. So, conservatively, the 40% claim suggests that at least 400,000 species are threatened with extinction.

So is it an accurate prediction? No. Here’s why: Continue reading

Moving on from the insect apocalypse to evidence-based conservation

Our insect apocalypse paper is finally published online at BioScience, with awesome co-authors Jasmine Janes and James O’Hanlon!

We summarise the major flaws in the pop culture ‘insect apocalypse’ narrative and argue that focusing on a hyped global apocalypse narrative distracts us from the more important insect conservation issues that we can tackle right now. Promoting this narrative as fact also sends the wrong message about how science works, and could have huge impacts on public understanding of science.

And, frankly, it’s just depressing. Right now, we all need hope, optimism and reasons to act, not a reason to give up.

This blog isn’t about the paper, you can read it yourself (journal, preprint, or email me for a copy). This is about why we wrote the paper. Continue reading

Book Review: The Last Butterflies

(This is the accepted version of my review published here in Trends in Ecology & Evolution.)

It is an unfortunate paradox that insects, the most abundant and diverse class of animals on Earth, are also the most understudied and misunderstood. With diversity comes complexity, and scientists have only scratched the surface on knowledge of global insect ecology. In The Last Butterflies, ecologist and butterfly expert Nick Haddad explores some of this complexity.

Despite the title, this is not a story of despair. Nor is it just about butterflies. Haddad weaves an absorbing narrative about the multidimensional process of science and insect conservation, the damaging impacts humans can have on the web of life, the ethical quandaries of conservation, and the positive changes and solutions that give us hope. Each main chapter is focused on a single butterfly species: six of the rarest North American butterflies that Haddad has spent his career studying, and two more well-known species from North America and the UK. The eight butterflies are framing devices, each one illustrating pieces of the challenging puzzle that is insect ecology and conservation. Continue reading

The windscreen phenomenon: anecdata is not scientific evidence

The windscreen phenomenon refers to people’s perception that there are fewer insects being splattered on their windscreen than they used to see. It is one of the most common anecdotes presented as evidence of global insect decline in the Insectageddon stories. But anecdotes are not scientific evidence. Anecdotes describe local conditions, not globally-relevant facts.

People often claim the ‘windscreen phenomenon’ is established evidence and proven fact. But a search of academic journal databases returns only one published study that has used car windscreens to measure changes in local insect abundance. In that study, Anders Møller compared insect abundance (although it’s not clear from the Methods if he actually measured density) with breeding rates of insectivorous birds in an agricultural landscape in Denmark. Data was collected in the same way at the same location for 20 years, which is very impressive, and analysis showed an 80% decline in insects across the period. Continue reading

The real Tinkerbell: don’t mess with these tiny fairy wasps

Have you ever seen a fairy? They exist, and may very well be in your garden. But you would need a high-powered microscope to spot the dainty creatures.

Fairy wasps (family Mymaridae) are tiny, feathery-winged parasitoid wasps. They’re often called fairy flies, which is a misnomer. The Mymaridae family includes the smallest known insects in the world. Most species are less than 1mm long – smaller than the average pinhead.

Read on at The Conversation.

© Manu Saunders 2019

Roosting insects: avoiding predators, or just after a cosy nap?

On Sunday, as I walked a load of washing to the Hills Hoist, an odd pattern caught my eye. It’s autumn here in Armidale (which is very cool climate by Australian standards) and temps have been cooling off for a while. But Sunday was our first proper cold snap, a lot earlier than usual and much colder than the March average minimum (about 11°C). We got down to about 3°C overnight and there was frost in some parts. I was shivering before I’d finished hanging the washing out.

Our vegie garden is effectively dead – a few late-ripening tomatoes and the flowering borders are hanging on. But as I walked past a dead plant full of dill seeds, something caught my eye. Continue reading

Bogong moths: pest, icon, or just another insect species we know very little about?

The Bogong moth story is a fascinating example of how complex insect life cycles don’t translate well to simplified sound bites.

Recent observations that there are fewer Bogong moths (Noctuidae: Agrotis infusa) in the Alps this summer made the news. One of the researchers credited with the observations found no moths in three caves he had visited last year, but he did find some in other caves in the region. There are limited long-term data on Bogong moth populations, and all of this news appears to be based on anecdotes, so it is impossible to verify if the species is truly in decline. Continue reading

Australia’s threatened insects

A couple of weeks ago I gave a talk at the Insect Ecology Research Chapter workshop at the Ecological Society of Australia’s annual conference in Brisbane. I talked about how policy and popular media influence insect conservation in Australia; as an example, I discussed this research by Toby Smith and me showing how introduced honey bees dominate mainstream media coverage of pollinators in Australia.

I also collated data on which insect species are officially listed as threatened species in Australia. In Australia, we have a national list (under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999) of flora and fauna species that are considered threatened at a national scale. In addition, each individual state and territory has its own threatened species list under various state legislation. Continue reading