The grasshopper's song: Britain's meadow musicians and a changing climate

Walk through a British meadow on a warm afternoon in late summer and the air seems to hum with a dry, ceaseless chirping. Step forward and something springs from beneath your feet, arcing through the grass before vanishing again. You have just disturbed one of the season's greatest and most overlooked performers: the humble grasshopper, whose song is the very soundtrack of the British summer.

The sound of summer

That familiar chirping belongs to grasshoppers and their close relatives, a group of insects known to scientists as the Orthoptera. Britain is home to more than two dozen native species of grasshoppers, crickets and bush-crickets, each with its own habits and habitats, from dry chalk downland and heaths to damp meadows and the tangled margins of gardens and fields.

Perhaps the most remarkable thing about these insects is their music. In almost every case it is only the males that sing, and they do so to attract a mate and to warn off rivals. A grasshopper produces its dry, buzzing song by rubbing tiny pegs on its powerful hind legs against a hardened vein on its wings, a technique that naturalists call stridulation.

Grasshopper or bush-cricket?

Although they are easily confused, grasshoppers and bush-crickets belong to two distinct groups. Grasshoppers have short, stubby antennae, are usually active by day and sing by scraping their legs against their wings. Bush-crickets, by contrast, carry extraordinarily long, thread-like antennae, are often creatures of the evening and produce their song by rubbing their wings together instead.

The difference can even be heard. The song of a bush-cricket tends to be higher and more mechanical than the cheerful chirp of a grasshopper, and many bush-crickets only strike up their tune in the late afternoon, singing on well into the warm nights of late summer when most grasshoppers have already fallen silent.

Built to leap and sing

Everything about a grasshopper's body is built for a life in the grass. Its enormously enlarged hind legs act like coiled springs, allowing it to leap many times its own length to escape danger in an instant. Its green or brown colouring provides superb camouflage among the stems and dry seed heads, so that a whole chorus of singers can remain almost invisible to the eye.

Most grasshoppers are harmless vegetarians, feeding quietly on grasses and low plants throughout their short lives. In turn they are a vital link in the food chain, providing an abundant meal for birds, lizards, spiders and countless other creatures. A meadow rich in grasshoppers is very often a meadow rich in all the wildlife that depends upon them.

Musicians on the move

In recent years these insects have also become unlikely messengers of a changing climate. As Britain grows warmer, several species have been steadily expanding their range northwards. The long-winged conehead, once confined to the south coast, has pushed more than a hundred and fifty miles inland over the past two decades, and is now found well to the north of Leicester.

The story of Roesel's bush-cricket is much the same. Long restricted to the estuaries of the Thames and the Solent, it has spread across southern and central Britain in recent decades, advancing dozens of miles as milder summers open up fresh territory. For entomologists, these quiet northward marches are among the clearest fingerprints of a warming world.

A grassland worth saving

Yet not every species is thriving, and the fortunes of our grasshoppers are closely tied to the health of the countryside. Many depend on flower-rich, traditionally managed grassland, a habitat that has become far scarcer as fields are ploughed, drained or cut too often and too early in the year for the insects to complete their life cycle.

Helping them is refreshingly simple. Leaving a patch of grass long and uncut, sowing native wildflowers and avoiding pesticides all give grasshoppers the food and shelter they need. Even a modest wild corner in a garden or a park can quickly fill with their song, offering a small but genuine refuge in an otherwise busy landscape.

Listen while you can

Late summer and early autumn are the very best time to enjoy these meadow musicians, when the adults are fully grown and in full voice. Stand quietly at the edge of a rough field on a sunny day, or linger there at dusk, and let the layered chirping wash over you before the first cold nights of the year finally still it.

For all their smallness, grasshoppers are a barometer of the living countryside, their chorus a sign that the grassland around us is still alive and well. To listen to them is to hear the pulse of a British summer, a sound worth pausing for, and one well worth working to protect for the summers still to come.