Rare finds revealed by Oswestry hillfort wildlife survey

A landmark survey has revealed that Old Oswestry hillfort is a magnet for wildlife, including species rarely seen or declining in Shropshire.

Experts discuss specimens at the Hillfort BioBlitz. Photo: Neil Phillips
Experts discuss specimens at the Hillfort BioBlitz. Photo: Neil Phillips

Following months of work to verify results, organisers have published the findings of the Hillfort BioBlitz, a 24-hour ecological survey carried out last July in blazing sun.

The event was organised by Turnstone Ecology in association with English Heritage, guardians of Old Oswestry, and hillfort conservation group, Oswestry Heritage Gateway. Funding contributions came from The Charlotte Hartey Foundation and Three Parishes Big Local.

The organisers have been delighted with the final listing of over 500 species. This includes 290 types of invertebrate improving significantly on the handful previously recorded. Numbers of invertebrates in the UK, such as bugs, spiders, butterflies and worms, have fallen by almost half in the last four decades, highlighting the important contribution of the hillfort and its environs to Oswestry’s ecology.

Bug, mammal and plant experts from across Shropshire and the West Midlands, including the Shropshire Wildlife Trust and Shropshire Botanical Society, identified many notable or rare examples that appear to do well in the hillfort’s unique environment.

Among highlights were six species of bat including the lesser horseshoe (Rhinolophus hipposideros) and Leisler’s bat (Nyctalus leisleri), detected during the night despite less than ideal conditions.

Clare Knight, the event organiser and an ecology consultant at Turnstone Ecology, said: “We had a number of exciting sightings such as the ghost moth, whose numbers are starting to struggle in the UK at the moment. It was also a bonus to see the larvae of the thistle tortoise beetle.”

The ghost moth appears on the UK Biodiversity Action Plan (UK BAP) as a priority species; although once common and widespread, it is rapidly declining, but is suited to the rough grassland on the hillfort. UK BAP remains an important reference of UK wildlife under most threat and requiring conservation action.

Volunteers and members of the public got the opportunity to help with the ambitious task of recording as many types of flora and fauna as possible on the hillfort ramparts. Data has been added to official ecological records and is informing landscape maintenance to ensure the hillfort’s archaeology and thriving ecology are safeguarded.

Helen Allen of English Heritage said: “We have long known about the fascinating story of human activity at Old Oswestry, but these findings provide us with a new picture of the natural story of the 44-acre site. I am grateful to Turnstone Ecology and Oswestry Heritage Gateway for all the efforts they have put into this interesting project.”

Neil Phillips of Oswestry Heritage Gateway said: “As well as helping with landscape maintenance and conservation on the hillfort, our group is keen to develop recreational and educational opportunities so people can explore and appreciate the site’s history and wildlife. We were pleased to see children and parents using nets, collection pots and microscopes at the BioBlitz and getting hands-on with the survey.”