Squirrels are present in the United Kingdom, with two primary species: the native Eurasian red squirrel and the introduced North American grey squirrel. While red squirrels have inhabited the UK for thousands of years, grey squirrels arrived more recently and have significantly expanded their population. The presence of both species has created a challenging ecological situation, especially for the smaller, native red squirrel.
The UK’s Distinct Squirrel Species
The UK is home to two main squirrel species, each with unique physical traits and behaviors. The native Eurasian red squirrel (Sciurus vulgaris) is recognized by its reddish-brown fur, often with a paler underside. During winter, red squirrels develop distinctive, long ear tufts, a feature absent in their grey counterparts. These animals weigh around 300g and have a bushy tail nearly as long as their body, used for balance and communication. Red squirrels primarily inhabit coniferous and mixed woodlands, foraging for seeds, nuts, and fungi, and building nests called dreys high in tree canopies.
The introduced grey squirrel (Sciurus carolinensis) is larger and heavier than the red squirrel, weighing around 540g to 700g. Its coat is predominantly silver-grey, and it lacks ear tufts. Grey squirrels are highly adaptable, thriving in various environments including mature deciduous woodlands, urban parks, and gardens. They construct dreys from twigs, leaves, and bark in tree forks and are known for their agility and ability to crack nuts efficiently.
Grey Squirrel Presence and Impact
The grey squirrel, native to North America, was first introduced to the UK in 1876 as an ornamental species on country estates. Introductions continued until around 1930, when their negative impact became clear, leading to regulations prohibiting their release into the wild. Since their arrival, grey squirrels have outcompeted native red squirrels across much of England and Wales. They are larger and more robust, competing effectively for food resources like seeds and acorns.
Beyond direct competition, grey squirrels pose a major threat by carrying the squirrelpox virus (SQPV). Grey squirrels carry the virus without showing symptoms or suffering harm, having developed immunity. However, when transmitted to red squirrels, the virus is fatal, causing painful lesions, scabs, and discharge around the eyes, mouth, and feet. This leads to dehydration and starvation, rapidly reducing red squirrel populations in affected areas. Additionally, grey squirrels damage trees by stripping bark from various species, impacting forestry and woodland health.
Red Squirrel Conservation Efforts
Efforts are underway to protect and conserve the dwindling native red squirrel population in the UK. Conservation initiatives focus on managing habitats to favor red squirrels and controlling grey squirrel numbers in red squirrel strongholds. Habitat management involves maintaining large blocks of coniferous woodland, which red squirrels prefer and where grey squirrels are less dominant. This includes ensuring a continuous canopy for safe movement and providing diverse tree species for year-round food sources.
Grey squirrel control measures are implemented to reduce their competitive pressure and prevent the spread of the squirrelpox virus. Under the Wildlife and Countryside Act 1981, grey squirrels are classified as an invasive non-native species, and it is illegal to release a captured grey squirrel back into the wild. Conservation organizations, such as The Wildlife Trusts and the UK Squirrel Accord, work with volunteers and landowners to monitor squirrel populations, undertake targeted grey squirrel removal, and manage woodlands. These coordinated programs aim to safeguard the remaining red squirrel populations and expand their range.