The author explains how nature can tell us whether or not to pack our raincoats
Why did you write this book?
I’m a forester, so I’m in contact with the weather every day. In Germany, as in the UK, it’s a bit of an obsession. I wanted to share how you can learn to read the signs.
The book is also about the simple processes of nature that surround us. Which are easiest to observe?
Thermals – columns of warm air – are obvious. On a fine day you’ll see fluffy cumulus clouds forming at the top and birds of prey soaring on the upward lift. Ants are also interesting. Their movements loosen soil, improve root penetration and help plants to disperse. Seeds bear sugary morsels known as elaiosomes; the ants haul these home for dinner and discard the seeds up to 70m away. Wild strawberries, dog violets and forget-me-knots all take advantage of this delivery service.
Can plants predict the weather?
Yes. The upper sides of daisy petals grow faster in warmer weather; the undersides in cooler conditions. So if rain is due, the petals droop or close; if it’s sunny, they open. Waterlilies can also close hours before rain.
What about birds?
Chaffinches modify their songs when the weather is set to turn – their ‘rain call’ is a simple, monosyllabic raaatch. It’s also said that when swallows fly high, summer will be dry – but the opposite is the case.
And pine cones?
Sadly not. They do open up in sunny, dry weather, but the change lags behind.
How does rain influence animals?
Earthworms, for instance, emerge because rain brings the risk of drowning in flooded burrows. There’s also a theory that the drumming of the rain sounds like the digging of predatory moles. Larger animals usually run for cover when it’s raining, but come back into the open to dry off when it stops. This is why the few minutes immediately after a downpour is a great time to watch deer.
How does aflower clock work?
Carl Linnaeus realised that different flower species open at different times of day, with impressive reliability: pumpkins at 6am, marigolds at 8am, and so on (touting nectar and pollen to pollinators when your rivals are still asleep gives a competitive edge). His idea was to create a clock with the time indicated by opening blooms instead of numbers and hands. Various botanical gardens attempted it in the early 19th century, but with mixed results.
Daisies close when bad weather is on the way.
The Weather Detective Rider, £9.99