Ecologists 'incredibly excited' after discovering rare southern damselfly on River Meon

Ecologists are buzzing with excitement after making history by discovering one of the rarest damselflies on the River Meon catchment.

The southern damselfly, also known as coenagrion mercuriale, has been identified by a group of ecologists from the Hampshire & Isle of Wight Wildlife Trust at St Clair's Meadow Nature Reserve near Soberton. The discovery marks the first known record of the species in the catchment.

Dr Ben Rushbrook, principal ecologist at Hampshire & Isle of Wight Wildlife Trust, said: "This is an incredibly exciting discovery. Finding a species as rare as the southern damselfly here shows just how important it is that we continue restoring, protecting and connecting the places wildlife depends upon.”

Over two consecutive days, ten male southern damselflies were recorded along a 675-metre stretch of the River Meon within the reserve. The first two individuals were spotted during a training exercise, prompting a return visit the following day to collect photographic evidence to support this discovery.

The southern damselfly is one of the UK's rarest damselflies and is listed as Vulnerable on the IUCN Red List. While Hampshire supports some of the country's strongest populations, its geographic distribution across the UK remains restricted to a relatively small number of suitable wetland habitats.

Tom Selby, ecologist at Hampshire & Isle of Wight Wildlife Trust, said: "We weren't actually looking for southern damselflies when we made the discovery. While taking part in a team botany training exercise at the reserve, my colleague Jo and I happened to glance over a fence into the River Meon and spotted something familiar to us from survey work elsewhere in Hampshire, but that we weren’t expecting to see at St Clair’s.

“Fortunately, I had my close-focusing binoculars with me, which allowed me to get a good look and confirm the identification.”

St Clair's Meadow Nature Reserve, which is managed by Hampshire & Isle of Wight Wildlife Trust, is home to a species-rich floodplain meadow habitat alongside the internationally important River Meon chalk stream.

The discovery highlights the importance of safeguarding healthy rivers and wetlands across Hampshire. The Trust hopes further surveys will reveal more about the population and whether the southern damselfly is established elsewhere within the catchment.

Ben added: “To maintain the right habitat conditions for southern damselfly requires management, otherwise the watercourses they live on would ultimately become dominated by scrub and trees. Its presence in large numbers could therefore indicate healthy and sensitively managed rivers and wetlands.”