A Hop of Hope

Rewilding
Reintroduction
Citizen Practice

Large Marsh Grasshopper
The LMG reintroduction team on a field trip

OVERVIEW

A partnership project led by Citizen Zoo and involving Norfolk Wildlife Trust, the Wildlife Trust for Beds, Cambs & Northants and Natural England has returned the large marsh grasshopper to a number of wetlands across Norfolk.

Large Marsh Grasshopper - Lucas Ruzo

PROJECT DETAILS

Species: Large Marsh Grasshopper (Stethophyma grossum)

Where: East Anglia

IUCN Red List Status: Near threatened but in the UK one of the rarest

Threats: Habitat loss

BACKGROUND

While the large marsh grasshopper is the biggest and most handsome of all British grasshoppers, it's also one of the rarest. The degradation and loss of their preferred habitat, fens and peat bogs, has constricted their range considerably. Today, it survives almost exclusively in the valley mires and wet heaths of the New Forest and Dorset. However, its former distribution included wetland habitats across Norfolk and the Cambridgeshire fens.

As a young organisation, Citizen Zoo is on a mission to create a world filled with wildlife – including endangered insects. We are idealistic, but also practical, and so when we realised it might be feasible to restore this magnificent grasshopper back to its former range in East Anglia, we worked to develop a project. In 2018, with consent from Natural England and the Forestry Commission, we safely collected a limited number of wild large marsh grasshoppers at several sites in the New Forest. Half were introduced directly at a wetland site in Norfolk. We brought the rest into captivity and allowed them to breed in carefully controlled conditions. Here they laid far more eggs than they would have done in the wild. These eggs were collected for hatching and home-rearing the following summer.

We could not have achieved this objective without the support and dedication of our team of volunteers, or ‘Citizen Keepers’. For 6-8 weeks during the past two summers, they each collected fresh grass daily, to feed hungry and growing young grasshoppers maintained in a home vivarium. A far higher proportion of grasshoppers were reared to adulthood in this way, in captivity, than would have survived from hatching in the wild.

Our first large marsh grasshopper reintroduction

It was really exciting when we released the first home-reared grasshoppers into the wild in Norfolk, in 2019! Our model of working with dedicated and passionate Citizen Keepers, combined with expert guidance and robust captive breeding for reintroduction protocol, meant that in both 2019 and 2020 we were able to release several hundred adult grasshoppers to build up what hopefully will be self-sustaining wild populations.

Imagine the thrill we felt in July 2020 when, during routine site monitoring, we discovered the first of many Norfolk-born males calling for females with their distinctive clicking stridulation. This was a milestone for the project. It showed the introduced species had completed its annual life cycle in the wild. The over-wintering eggs had hatched in early summer and passed through four nymphal instars, before becoming an adult. These males came from eggs laid in the wild by home-reared grasshoppers released in 2019. Hopefully, the first of many generations to come of Norfolk large marsh grasshoppers.

Climate change and habitat fragmentation mean that this species will face ever-growing threats to its survival. Through the commitment, collaboration and expert advice from our partners, scientists, keepers and statutory bodies, we are confident that we can turn the tide together and give this rare species a fighting chance in years to come.

Get involved to help the large marsh grasshopper

To support the project why not donate today to help us protect the large marsh grasshopper? Or to pledge your support long term, why not become a member?