Why would you tickle a cricket?

In the 1980s, there were only around 100 field crickets left in the UK. Here’s how they came back from the brink.

Insects in trouble

Although they may make some of us squirm, insects are one of the most important and populous creatures on this planet. They’re bound up with many vital ecological processes, from pollination to the breakdown of dead matter, and because they’re so important, when their numbers fall, it can signal big problems elsewhere in the ecosystem.

We know that many of our insect species in the UK are in trouble, but it’s often the showy, easily-recognised examples that hit the headlines, like bees, butterflies and ladybirds. In the south of England, however, the RSPB has been trying to support a tiny and unassuming insect with the aid of a little bit of tickling.

Tug at the harp strings

The striking song of field crickets would once have been common on the heaths of West Sussex, Surrey and Hampshire. At only 2cm long, and spending most of their lives underground, field crickets are chunky, black or brown in colour with yellow at the base of their wings. Despite having wings, they can’t actually fly, though they are able to walk surprisingly far, up to 100m in a day. Their loud chirping call is used to attract a mate, and is created by the males rubbing areas of their forewings together, which is known as their ‘harp’.

When is a cricket a grasshopper?

Crickets and grasshoppers can be tricky to tell apart. There are actually 30 different species from the family ‘Orthoptera’ found in the UK, and although most live in the south, some can be seen right up in the far north of Scotland.

Field crickets are one of only two ‘true crickets’ (in a family called Gryllidae) that are native to the UK, the other being the wood cricket. One of the easiest ways to tell them apart from grasshoppers is by the length of their antennae (these are shorter in grasshoppers), but their sheer rarity is the biggest give away. These days, you’d be extremely lucky to see one.

Almost all out

Changing farming practices after WWII certainly created problems for our chirping field crickets, but it was the loss of their favoured heathland habitats that was to prove particularly devastating. A staggering 70% of England’s heathland was lost during the 20th century, mostly due to house building and commercial forestry plantations, and it’s not just the field crickets that were affected. Birds like nightjars and Dartford warblers, along with many species of invertebrates and plants, and reptiles like the smooth snake, have all seen a big drop in numbers.

With their limited mobility, however, the field cricket was particularly hard hit, and by the 1980s, it was estimated that there were only around 100 left. To make matters worse, they were all restricted to a single site in West Sussex, making them extremely vulnerable to local extinction.

The slow start of the bounce back

In 1992, a programme of reintroductions using captive-bred field crickets started at sites across Surrey, Sussex and Hampshire, but only three of these groups survived. So in 2010, much more targeted efforts were made to create a larger, stable population. As part of this, the RSPB translocated a group of field crickets to an area of Farnham Heath reserve, where conifer plantations had recently been removed to restore the heathland. This project was very successful and a population of over 300 field crickets became established in just six years. All the new populations were still very isolated, however, and the future of the field cricket was far from secure.

The secrets of cricket tickling

In 2017, new hope came in the form of a National Lottery-funded programme called Back from the Brink. This aimed to extend and join up areas of the crickets’ preferred habitat and start new populations by translocating them to restored heathland.

But translocating an insect that rarely comes above ground requires a certain amount of skill. To catch the crickets, licenced volunteers used a technique called ‘tickling’. This involves pushing a stiff blade of grass into a cricket’s burrow and poking it gently around. If there’s a young cricket in residence, then they grab hold of the grass, and can usually be persuaded up to the surface. It takes a bit of practice to get it right, and a lot of patient wiggling of grass blades into empty burrows to find one that’s occupied.

The final cricket tickling translocation was planned for this spring, but sadly, it couldn’t take place due to lockdown restrictions. But all was not lost.

Singing in the midst of lockdown

When reserve wardens went out to Pulborough Brooks and Farnham Heath reserves this spring to perform vital checks, they were thrilled to hear the unmistakable chirping of field crickets. The singing could only mean that the crickets from the previous translocations had not only survived, but bred, as these were their offspring, now emerging in the spring, and singing to attract a mate. It was a welcome result and a definite sign of hope.

More work will likely be needed in the future to help support our field crickets, with further heathland restoration high up on the agenda. But despite low numbers, and plenty of obstacles, these tiny, chirping insects have managed to cling on, and with luck, their distinctive song will be heard for many years to come.