27 March 2019updated 08 Jul 2021 12:35pm

In churches I find an array of wildlife: from carvings of beavers, stags and herons to medieval Green Men myths

A stone cross marks the site of an ancient tomb at the foot of a tree and covered by tall grass. In the background, there are other patinated stone crosses lost in the vegetation. Photograph taken at Brompton Cemetery, London, UK. Brompton Cemetery is one of the Magnificent Seven Cemeteries, a set of 19th-century London landscape cemeteries.

The village of Woolpit (an Old English word for wolf-trapping pits) could stake a good claim to being the folkloric epicentre of Suffolk. The village sign depicts the legend of the Green Children, a 12th-century story of a boy and girl who emerged from a parish wolf-pit into a field. Their skins were green and they refused to eat or speak until they were offered beans. When they learned English they said they came from a land of perpetual twilight, beyond a great river.

The story sounds like a mix of an “Otherworld” fairy story, a harvest myth of transubstantiation and maybe a folk memory of real immigration. The parish church is full of intricately carved animals. Almost hidden in one corner is a creature that might also have emerged from the wolf-pits – a “wodewose”, a roughly carved stone wildman, etched with scales or matted fur. A label suggests, almost apologetically, that this unholy effigy is from Asia – but images of wildmen are frequent in East Anglian churches.

I’m not a conventional church-crawler. But I am intrigued by their iconography, especially the considerable proportion that is nature-based. I like the glimpse it gives into the medieval mind, and the way that meticulous observation morphs seamlessly into metaphor. The local landscape leaks into the church, distilled by craftspeople with a deep knowledge of religious symbols, or by local carvers with a gift for caricature.

So, on damp Sunday afternoons we often venture out, searching for the green language. All Saints, Dickleburgh is something of an ark. Lions and wildmen protect the angels on the octagonal font. Instead of a gallery of saints, the rood screen has a cast of figures that seems to have come out of Aesop’s Fables: a rabbit caught by its hind legs, a fox with a goose in its jaws.

Out to the west, along what is still known as the “shoreline” of the Fens, the great wool churches are full of local wildlife. On the bench ends and choir stalls at Mildenhall there is a bestiary of what was then England’s largest and wildest wetland. There are fishes, beavers, stags racing through the reeds and herons stabbing eels. Here, and in Lakenheath church, the carved timber roofs are breathtakingly magnificent. The air above you is full of wooden angels, just taking off from the hammer beams. These aren’t the angels of Renaissance paintings, with broad wings neatly folded, but creatures in full flight, with long narrow wings and splayed feathers. These medieval carvings were inspired by marsh harriers, then common fenland birds whose glorious spring sky-dancing has a numinous quality. At a time when angels were believed to be real entities that visited earth, why not see them and the great birds of the marsh as on a single continuum of flying creatures?

The choicest finds are Green Men, lurking in porches and on columns. These “foliate heads”, with leaves gushing out of their mouths and nostrils, were appropriated by the church as a warning of the corruption of the flesh. But they are a much older pagan symbol of the circularity of life. Norwich Cathedral has eight: imps, gigolos, jack-in-the-greens.

I’m glad I don’t live at a time when the boundary between reality and fantasy was so porous. But I’m continually touched by the way these vernacular artworks – biologically attentive, comic, reverent, sometimes subversive – slip so unselfconsciously into our edifices of the supernatural.