It might sound like we’re talking cow-dung, but many areas of the UK have a problem with poisonous cow-pats, as the cattle are dosed with Avermectin wormers. These cause terrible problems for species of dung-beetles and, moving up the food chain, on the wildlife that depends on this dung fauna.

Remarkably, since we have owned them, our cattle have never been wormed. Tests on their dung find virtually no evidence (if any) of worm infection. As a result, our cattle’s dung is free from persistent poisons, and a feasting ground for dung-flies and dung-beetles, and the predators of the dung-devourers.

So why is our cow poo so clean? Well, it could be that they are constantly moving around St Mary’s, spending a few days on one section of coastal heathland or grassland, before moving to the next. Such a light stocking density, with months between the cattle visiting, means that any parasitic worms will find it very hard to re-infect the herd.

There may be another reason, too. Our cattle are brilliant conservation grazers, enjoying a munch of just about everything that’s available to them. To our initial horror, they have always made a beeline for the hemlock water-dropwort when they are at Higher or Lower Moors. They seem to love the taste of the lush leaves of what’s one of Britain’s most poisonous plants. We always move them on before they’ve eaten too much – and certainly before they have the chance to poach the ground and expose the ultra-toxic roots (the so-called ‘dead man’s fingers’ or ‘poisonous parsnips’) - but perhaps a dose of the water-dropwort leaves acts as a natural wormer. It’s certainly not something we’d recommend for cattle, but ours seem to be fine despite their dangerous penchant.

From an ecological point of view, we’re delighted with our cow pats. There’s a whole food chain within every pile of dung, digesting it in double quick time. What emerges from the dung supports a whole host of other life, too. We had a pair of choughs around our cattle-grazed coastal areas (like Peninnis and Deep Point) overwinter two years ago – rare birds on Scilly, despite the Cornish population which is now booming! Choughs love short grass where they can pick out leatherjackets and worms, and the cattle don’t just provide the right length of grass, the dung-beetles that follow our cows are themselves a crucial chough food item.

We’d like to say a huge thank you to Kylie and Dave at Salakee Farm who leant us their Dexter Cattle for a few weeks, too. In such a mild winter, our small herd haven’t been able to keep up with their workload, so the Dexters have been helping us keep up with grazing.