My youngest child is fascinated by the word ‘jizz’. This word often forms part of the answer when a birder is asked how they know that a distant object is a particular bird. The word either comes from a deliberate misspelling of the acronym for ‘general impression, size and shape’, or a shortening of ‘it just is’. Either way, jizz can be equally useful for helping to identify butterflies.
General impression is quite a good way of narrowing down what you are looking at, and in some cases is even captured in a butterfly’s name. Fritillaries are amongst our largest butterflies and have a floating flight that seems to match their name. I’m told that you can even tell the different types of fritillary by the way they fly. Skippers, a much smaller butterfly, bob along at plant height seemingly skipping from plant to plant. Gatekeepers venture out from their preferred resting-spot to chase off intruders irrespective of the intruder’s size.
General impression also covers colour. In the butterfly world, we have the unimaginatively named whites, blues and browns. Slightly more helpful names include speckled woods (if you are in a woodland area and see a brown and white butterfly flitting around it’s probably a speckled wood), orange tips and brimstones.
Our native butterflies range in size from the small blue and the skippers, which are not much bigger than a thumbnail, to the purple emperor, which is almost the size of your palm.
Although butterflies generally have a similar shape, there are a few variations that help identification. The admirals, emperor and painted lady have a concave edge to the forewing, whereas the comma has a raggedy edge to fore and rear wings. The swallowtail, a rare summer visitor to eastern England, has what looks like a tail, and the hairstreaks have something similar but smaller. The hairstreaks are named after a line on their under-wing.
We are now approaching peak butterfly season, so see which species you can spot. The annual Big Butterfly Count is running between 17th July and 9th August and free charts and apps are available to help you identify what you are looking at (https://www.bigbutterflycount.org/). You could also take part in Butterfly Conservation’s Garden Butterfly Survey (https://gardenbutterflysurvey.org/).
If you want something that covers a few more species than Butterfly Conservation’s chart, then I recommend the Field Studies Council’s ‘Guide to the butterflies of Britain and Ireland’. If you want to know more about butterflies and the history of the people who named them, collected them and painted them then read ‘Rainbow Dust’ by Peter Marren.