Wildlife surveys at Bath City Farm over the last eight years have recorded species that a generation ago would have been rare in the area, ecologists have revealed.
A Red Admiral butterfly at Bath City Farm | Photo courtesy of Bath City Farm
The species, which are now common occurrences in Somerset, would have been rarities sixty miles south on the English coastline.
1,250 species have now been recorded at the 37-acre farm on a north-facing slope between Twerton and Southdown in the west of Bath.
30 of the species found on the grasslands and in the woods on the site are recent arrivals to the area, as warmer weather sees new species moving northwards.
Ecologist and Trustee, Mike Williams, who has led the wildlife recording, said: “Insects are important indicator species that help ecologists understand the realities of a changing climate on our natural world.
“Spiders are a classic example as due to their short lifespan and mobility they react to changes in weather.
“Three years ago, the elegant Wasp Spider was recorded on the Farm for the first time ever and is now increasingly common in the area.
“In the early 1990s I only ever saw the Wasp Spider on the south coast of England, in Dorset.
“This was at the extreme north of their range because it was too cold for them. I would never have imagined then that one day they would be found as far north as Bath as we live with the realities of climate change.”
Butterflies at the farm were severely impacted by the dry spring and wet summer with fewer numbers recorded this year.
The Red Admiral has bucked the trend because fewer cold snaps and frosts have seen these summer migrants overwintering in the UK and breeding in the springtime which has led to greater numbers.
The Jersey Tiger Moth, which was only ever found on the Channel Islands, has become an increasing sight across the South of England, including at Bath City Farm.
Other recent new arrivals include the Hornet and Lesser Hornet Hoverfly, two harmless species that closely resemble Hornets, the Ivy Bee, which is now a common sight on Ivy flowers in the autumn, and the small green Ivy Spider, which was filmed on the site in 2022 for BBC’s Autumnwatch series.
A lack of frosts can have a devastating impact on plants, such as the Yellow Rattle, as it’s so fundamental to their lifecycle.
With warmer temperatures, this plant can struggle to germinate having a knock-on effect on pollinators and herbivorous insects, which in turn provide food for birds and bats.
Mike continued: “Our wildlife surveys have shown that climate change isn’t something that will happen in the distant future.
“It is having a clear impact on species across the UK, including impacting the wildlife that calls the Farm home.
“Most of the crickets you hear calling in the meadows have only been in Bath for the past 20 years or so – these are Roesel’s Bush-cricket and Long-winged Conehead.
“The former is very loud and very numerous. I tell people on my nature walks around the Farm that they are listening to the sound of climate change when we hear them.”
