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

Insect apocalypse: no simple answers

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

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© Manu Saunders 2019