Jersey’s Rare Lizards Under Threat from Habitat Decline

Jersey’s Rare Wall Lizards Face Threat as Habitats Deteriorate

Conservationists are warning that Jersey’s distinctive wall lizards — the only native population of their kind in the British Isles — could face local extinction in certain parts of the island unless their habitats are protected and better connected.

Research ecologist Nina Cornish has highlighted concerns over isolated colonies, particularly the group at St Aubin’s Fort, where lizards are struggling to find mates due to geographical separation. Without the ability to interbreed with other populations, genetic diversity declines, putting the group at risk of dying out.

“Connectivity is key,” said Mrs Cornish, who has conducted genetic research into the origins of Jersey’s lizard populations. Her findings show that the St Aubin’s group has a distinctly different genetic profile compared to lizards elsewhere on the island — underscoring the importance of preserving varied gene pools.

Dr Tim Wright, head of Jersey’s biodiversity team, added that the shrinking population at the fort may be the result of inbreeding, as well as predation by rodents and the spread of dense vegetation. “We suspect that declining habitat suitability may be the key cause,” he said.

While lizard numbers at Mont Orgueil, Rozel, and Bouley Bay remain stable, the increasingly fragmented nature of suitable environments threatens isolated colonies. The Government of Jersey, alongside the Jersey Biodiversity Centre, continues to monitor populations through its Reptilewatch programme, encouraging islanders to report sightings of the elusive reptiles.

Mrs Cornish, who worked with Oxford University on tracing the lizards’ lineage, said genetic evidence suggests the species has been in Jersey since before it was separated from mainland France. Historical anecdotes even describe French prisoners in the island’s fortifications keeping lizards as pets in their pockets.

The Channel Islands’ wall lizards are part of a broader European species group also found in France, Italy, and northern Spain — but Jersey’s populations are uniquely adapted to the local climate and terrain.

The Government’s biodiversity team praised its dedicated volunteers who help gather vital data year-round, helping to build a clearer picture of the species’ movements and numbers.

“It’s not just about protecting a single animal,” said Dr Wright. “It’s about maintaining a thriving ecosystem — and Jersey’s wall lizards are a visible part of that story.”