Some interesting syntheses of long-term insect data have been published in the last few months. These synthesis studies attempt to provide an answer to the big question mark raised by the recent insect apocalypse narrative.
This is how much of an impact a single study that gets lots of attention can have on the direction of science. The insectageddon opinion piece that started this ball rolling had fundamental flaws that are now well-documented (unfortunately it is still being widely cited in scientific literature and popular media as supposed evidence of decline). Sure, one could argue it got people talking about an important issue that we already had decades of evidence for.
But at what cost? Its long-term effects on science communication and scientific efforts are most concerning, something we flagged in our analysis published earlier this year.
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
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
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
(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 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
After my blog post earlier this year on the questionable insectageddon review paper, American Scientist invited me to write a perspective article on the media hype surrounding the story.
The review paper has many flaws and caveats (stay tuned for a more thorough treatment of the paper coming soon) and the breathless media hype around it was confused and misleading. But the overall message is valid – our collective actions are impacting ecosystems (including insects) in dangerous ways through forest clearing, pesticide use, fossil fuels, and widespread simplification of landscapes. Some insect species are being seen less frequently in some areas because of this.
However, this message is not new – we already have access to decades of more rigorous evidence showing these effects and how we can mitigate them, so the engagement value of this latest review paper is unclear. Is it worth risking public trust in scientific rigour, just to get a bit more attention for the issue?
You can read my article here: No Simple Answers for Insect Conservation
© Manu Saunders 2019