Looking out over rolling green landscape on the Shropshire/Wales border, the ancient beauty of Old Oswestry hillfort draws visitors from far and wide.
Now a landmark survey has revealed that the 3,000-year-old monument is also a magnet for wildlife, including species rarely seen or declining in Shropshire.
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.”
Beetle finds were a particular success on the day. In attendance was county beetle recorder, Caroline Uff, who was delighted to identify a relatively uncommon black birch pot beetle (Cryptocephalus labiatus). Pot beetles are leaf beetles whose larvae live most of their lives inside a pot made of their own droppings, providing camouflage and protection from predators. Almost all of the UK’s 19 species of pot beetles are rare.
Ms Uff was also surprised to see a red-legged springtail stalker (or ground beetle – Notiophilus rufipes), a species that is not well recorded in Shropshire and more usually found in old, damp woodlands in leaf litter. Her report also confirmed healthy numbers of the Lagria hirta, part of the darkling beetle family which is not seen in the County at all some years.
Lepidopterists were on hand to record no less than 85 butterflies and moths. They include varieties in decline such as the large white butterfly (Pieris brassicae) and also the wall (Lasiommata megera), which is currently on the Butterfly Conservation red list of those most at risk in Great Britain. Among moths identified were two woodland varieties seeing a decrease nationally, the buff-tip (Phalera bucephala) and peach blossom (Thyatira batis).
The hillfort’s spider population was a huge draw on the day for younger visitors. More than 30 types of arachnid were found, with weird and wonderful names such as the spotted wolf spider (Pardosa amentata), the turf running spider (Philodromus cespitum) and cucumber spider (Araniella cucurbitina sens. str.).
Experts also identified the nursery web spider, the female of which will sometimes attempt to eat the male after mating, although can be dissuaded if he offers a gift, such as a fly.
In addition, a total of 171 plants and six mammal species (excluding bats) were recorded.
A team from the Shropshire Botanical Society led the challenging task of plant identification, recording an impressive 166 species to add to existing data for the site, featuring intriguing names such as squirrel-tail fescue, sticky mouse-ear and smooth hawk’s-beard. Following verification by county recorder, Sarah Whild, the list has been added to the official records database of the Shropshire Ecological Data Network.
Findings included 21 axiophytes, plants regarded as special, though not necessarily rare, which are representative of Shropshire’s special flora and indicators of habitat considered important for conservation. Among them was the greater broomrape (Orobanche rapum-genistae), a plant that is parasitic on gorse and broom and has been in decline in the UK for some time though survives on the hillfort.
Species of lizard, newt, frog, grasshopper, dragonfly and millipede were also observed, as well as some 30 bees and wasps among a strong showing of pollinators on the hillfort.
As a place that rings with the distinctive sound of the skylark, chaffinch and yellowhammer, it was no surprise that the hillfort provided numerous bird sightings, 37 different species in all. Eight appear on the RSPB’s red list of birds at highest risk of decline; these are the starling, yellowhammer, linnet, skylark, song thrush, mistle thrush, house sparrow and yellow wagtail. Five of them – the meadow pipit, swift, house martin, lesser black-backed gull and bullfinch – are on the amber list representing the next level of conservation concern.
Experts at Turnstone Ecology, English Heritage’s ecology consultant for Old Oswestry, were particularly reassured to see newt and frog activity following efforts to improve the habitat of the hillfort ponds.
Work to replenish water levels has been a focus of landscape management activities with the help of the Oswestry Heritage Gateway. Volunteers returned to the ponds earlier this year to clear overgrowth to maintain the improved water volumes. Turnstone Ecology has undertaken a dedicated survey and keeps a watching brief on the hillfort’s protected newt population which includes all three UK species – the great crested, palmate and smooth newt.
“There are plans for a follow-up BioBlitz, potentially in 2020, once the landscape management programme is well underway,” said Clare Knight.
One of the nation’s most notable Iron Age sites, Old Oswestry is protected both as a heritage and envi-ronmental asset, being designated as a scheduled monument and Local Wildlife Site (LWS). It also lies within the Oswestry Uplands, one of 159 National Character Areas (NCAs) in England designated by Natural England for their special landscape, historic and environmental value and distinctiveness.