Managing Wildlife to Enable Us to Make Food
Rats and mice are always around us, whether in the countryside or urban areas. Rats, in particular, seem to be on the rise. Flax, being high in oil and rather tasty, is incredibly attractive to rodents, and the delicious smells of Flaxjacks baking in our kitchen must be particularly enticing.
The common brown rat (Rattus norvegicus), now widespread, only arrived in the UK in the 18th century. The earlier invader, the black rat is now rare. There are five truly native mouse species, of which three can cause problems by spreading disease, damaging property and contaminating food. While “live and let live” sounds appealing, our presence often gives rodents an advantage: we create shelter, disturb their predators and can easily drop more than enough crumbs to sustain them. Left unchecked, they could multiply rapidly and become a serious nuisance for us and our neighbours.
Managing the threat from rodents is, inevitably, part of the responsibility of producing food but it’s not as simple as just calling in pest control and putting down poison.
Traditional Pest Control v Wildlife-Friendly Methods
Until recently, almost all rodent poisons were anticoagulants indiscriminate in their action, wiping out rats, mice, and voles alike. These poisons left little behind for natural predators like birds of prey, mustelids, and foxes. Worse still, they posed a serious threat of secondary poisoning affecting any wildlife, pets or poultry that ate a poisoned rodent. Yes, really, our free-range bantams eat the mice and rats whenever they get the opportunity!
We’re lucky to have four species of owl nearby, tawny, barn, short-eared, and little owls as well as kestrels. Some nights, tawny owls can even be seen hunting in the garden. Sadly, these beautiful birds of prey are becoming increasingly rare, and traditional rodenticides are a major factor in their decline. To protect them, local pets and poultry anticoagulant baits were not an option for Flax Farm.
Yellow-Necked Mouse Invasion!
For years, we felt confident that our buildings were rodent-proof. Occasionally, we’d see the toothmarks where a mouse had tried to get into the bakery, but the dogs scared them off and it wasn’t a problem.
A couple of years ago, the scent of baking Flaxjacks must have drifted deep into the woods and proved irresistible to yellow-necked mice (Apodemus flavicollis). These are the UK’s largest mouse species similar to ordinary wood mice, but about 50% bigger, more golden in colour, and with a distinctive yellow band across the chest.
They came in droves. Every morning, we’d find fresh gnaw marks on the doors. Traps were catching up to six mice a night. We were under siege and something had to be done.
Working Cats to the Rescue
We contacted the Celia Hammond Animal Trust, a wonderful charity that rescues feral cats and rehomes them into safe working environments. They brought us two beautiful young cats that were quickly (and unimaginatively) named Ginger and Tortie. For the first month, they lived in a pen in a shed to settle into their new home. They were terrified and I barely saw them, even when taking them food.
Once released, they got to work. Almost immediately, the mouse problem vanished. After the first night the mouse numbers dropped in less than a month there were no mice trying to get into the bakery. The cats’ mere presence seemed enough to scare off would-be intruders.
They’re still slightly shy but are lovely cats and do a brilliant job. Tortie prefers to stay near the house, while Ginger has turned out to be a particularly fearless hunter with a great work ethic, dedicating his hunting hours to removing rats and now helps protect neighbours’ chicken runs too. They’re a key part of our team and even safe around the bantams (though we’re always careful). Both now enjoy hanging out with people and adore the dogs so we think they were probably once pets before being abandoned to a feral colony near Heathrow.
Production and Plan B
Around both the bakery and our production site, where we mill Flaxseed and cold-press Flaxseed Oil we rely primarily on humane traps deliciously baited with Liquorice Allsorts and Haribo Milkshakes sweeties. Any captured mice are relocated somewhere nice far enough away not to return.
If rodent numbers start to become a problem there is a plan B. .
Environmentally Safer Rodenticide: Cholecalciferol
Plan B is a new type of rodenticide that doesn’t cause secondary poisoning. It uses cholecalciferol, a type of vitamin D. When consumed by rodents, it causes a build-up of calcium in their blood, leading to their death but it has been shown to be safe for predators and pets that might eat the affected rodents.
Cholecalciferol bait has been extensively tested to show it doesn’t harm owls or other creatures though secondary poisoning.
To use the cholecalciferol-based bait made by BASF, Selontra®, I had to complete special training and licensing. It’s an effective product. At around three times the cost of traditional rodenticide it’s not cheap but for Flax Farm, it’s absolutely worth it.
Flax Farm’s Integrated Pest Control
We have an organic, integrated, wildlife-friendly pest control plan that includes:
- Working cats that deter and keep rodent numbers down naturally especially around production, the bakery and chicken areas.
- Live traps and safe relocation when necessary.
- Minimal use of Selontra, a modern cholecalciferol rodenticide, only as a last resort. This can be used safely without risking secondary poisoning of poultry, pets, birds of prey and other wildlife.
- Birds of prey, owls have always been considered part of the pest management around farms. By avoiding routine use of anticoagulant rodenticides, we support healthy populations of voles and mice which in turn support local owls and kestrels and keep them healthy. We believe that managing nature works best when done with nature, not against it.
At Flax Farm we believe we can produce food with respect for people, Nature and its wildlife.
References
- Background: The Rat Poison Problem
- Study: Cholecalciferol rodenticide and its impact on barn owls
- The Barn Owl Trust – Hazards of Rodenticides