Norfolk’s population was bolstered by 829 new arrivals last summer, but you’d be forgiven for having failed to notice this fact. At just 4cm long and extremely well camouflaged in their surroundings, the county’s newest residents aren’t exactly conspicuous. But their presence is no less significant for all that, representing a huge win for conservation in this part of the UK.
The large marsh grasshopper, the largest of the UK’s 11 native grasshopper species, used to be a common sight in the Fens and the Broads. But with drainage in the 19th century, suitable habitat became fragmented and the species became rarer and rarer until finally, in the 1960s, it went extinct. Since 1968 the large marsh grasshopper’s range has been restricted to a few sphagnum bogs and valley mires in Hampshire and Somerset. Now, thanks to the hard work of conservation group Citizen Zoo, it is back in Norfolk.
In June 2018 a group of Citizen Zoo staff and volunteers headed down to the New Forest for a weekend of hopper hunting. Using a collecting method that safeguarded the ongoing viability of the New Forest’s grasshoppers they captured 48 adult insects, all in pristine condition for breeding.
“We were so lucky because it was really hot,” remembers Dr Stuart Green, lead entomologist for Citizen Zoo and a grasshopper specialist. “When it's not sunny they hide away. It gave us a fantastic kickstart to the whole thing.”
Of those initial 48 hoppers, 30 were released on a Norfolk nature reserve whose location remains a closely guarded secret (two of Citizen Zoo’s partners, Natural England and the Norfolk Wildlife Trust, are concerned about the potential negative impacts of well-meaning hopper fans). The remaining 18 grasshoppers went home with Stuart, who began working out how to breed them.
Stuart has decades of experience with other species of grasshopper but the large marsh grasshopper was new for him. “Would these grasshoppers, with their squidgy, wet, squelchy habitat, survive once we put them in a hot, dry locust cage?” The answer was an emphatic ‘yes’. “They not only survived, they reproduced enthusiastically!”
Stuart collected dozens of egg pods – each containing 14 eggs on average – and stored them for months in moist sand, first at room temperature, then in the fridge, then in an incubator to mimic the changing of the seasons in the wild.
And then he waited. For a few days, nothing happened. Then, just as Stuart was about to give up hope, a couple of larvae, known as nymphs, appeared. Watching them wriggling their way up through the sand to bask under an incandescent bulb, the entomologist was hugely relieved. But that was just the start: “The next day, all hell broke loose and we had about 200,” he says. “It was absolutely heaving with tiny grasshoppers.”
Now they knew it was possible to breed and rear the insects in captivity, the next phase of Citizen Zoo’s large marsh grasshopper project swung into action – it was time to recruit the citizens.
“My personal frustration is that conservation organizations don't include local stakeholders in these types of projects,” explains CEO Lucas Ruzo. “Many new rewilding conservation projects aren't scalable, and they're often not scalable because the way that they're designed is very centralized.”
Citizen Zoo likes to do things differently. By training and equipping ordinary people to raise grasshoppers in their own homes, using donated equipment, the organisation massively increases the scope of the project, while keeping costs low.
Librarian Amy Stocking rearing her grasshoppers in her spare room. She became quite adept at dealing with runaways: “You’d see one ping and you’d think, where’s it landed?
“Even though I appreciate wildlife, I’ve never really got up close and personal with insects and I’m a little bit of a jumpy person. So when they were jumping it was making me jump!” she said.
Rearing the hoppers was satisfying, she says, but the most special element of the project were the release days – there are two each summer, with volunteers receiving a second batch of egg pods after freeing their first grasshoppers. “As soon as you released them, they were off, munching, flying and mating – living their best lives.”
Even with a relatively small number of volunteer keepers – up to 10 per year, usually – the results of the project are impressive. In 2019, the first year of the programme, 957 volunteer-reared hoppers were released at Citizen Zoo’s two sites in Norfolk. In 2020, it was 1,192, and in 2021, when they added Wild Ken Hill, just north of Sandringham, 1,068 captive hoppers found their freedom. Last year’s figure, 829, was a little lower than usual because the abnormally hot summer weather led to higher mortality among the caged grasshopper nymphs. Even so, those numbers are not bad when you consider that the project costs less than £2,000 a year to run.
The large marsh grasshopper project will continue this summer and hopefully beyond. As L:ucas explains, “We're going keep doing it until they're restored.”
All the signs are encouraging so far. Not only has the team spotted captive-bred hoppers at their sites many weeks post-release (identifiable via dots of paint applied by the keepers), but they’ve seen more unmarked adults too, living proof that previous years’ captive-bred hoppers produced offspring in the wild. The hope is that one day the species will be able to sustain itself, rather than requiring topping up by Citizen Zoo every year. In the meantime, the project is bringing great joy to those fortunate enough to take part.
As Amy recalls, “it just felt so lovely to know that I had reared these grasshoppers and now they were going to go off into the wild, exactly where they were supposed to be.”
Citizen Zoo is looking for new volunteer keepers in Norfolk – find out more at citizenzoo.org
