Conservation & Ecology


absence of competition and with predators also being supressed, the population exploded - by 1930, the population covered 25,693 km2


and, five years later, this area had


nearly doubled. The impact of this spectacular growth in numbers resulted in The Destructive Imported Animals Act in 1932, making it illegal to import, keep or release grey squirrels. Propaganda was produced promoting the control of grey squirrels: in 1936, twenty-six county councils distributed more than 5,000 posters entreating the general public to “kill the tree rat”. In 1937, it was designated a pest because of the damage it did to trees and cereal crops and a bounty system was established to try to control the population. In 1943, County War Agricultural Executive Committees issued free shotgun cartridges to registered grey squirrel shooting clubs to reduce their numbers (MAF, 1943). By the end of 1947, 450 shooting clubs had killed 100,000 grey squirrels. This had little effect. By the 1950s, the grey squirrel occupied the whole of central England and was still expanding its range by over 2,500 km2


per


year. By 1952, approximately 7,000 grey squirrel shooting clubs were in existence and, in 1953, the first anti-grey squirrel propaganda was broadcast on Radio 4’s The Archers. An experimental bonus system was introduced to complement squirrel clubs; one shilling or two free cartridges paid per grey squirrel tail. The bounty was raised to two shillings in 1956. 1,520,304 grey squirrel bounties were paid in five years with no effect on their numbers. This system was abandoned in 1958 when it was demonstrated that trapping was more efficient than shooting them.


“


Where grey squirrels have been increasing both in terms of numbers and their range, red squirrels have diminished. There are now over three million grey squirrels and less than 160,000 red squirrels, with some forecasts stating that the red squirrel will be extinct in the UK by 2031. The IUCN places the grey squirrel in its top 100 most invasive species. Grey squirrels outcompete red squirrels for


By 1952, approximately 7,000 grey squirrel shooting clubs were in existence and, in 1953, the first anti- grey squirrel propaganda was broadcast on Radio 4’s The Archers


resources: whilst both species feed predominantly on seeds and fruit throughout the year, they are capable of adapting their diet to take advantage of the seasonal abundance of different foods. Specifically, red squirrels eat acorns,


berries, fungi, bark and sap tissue; soil and tree bark are also eaten, probably for roughage and minerals. Grey squirrels will eat mast (mast is the fruit of forest trees such as oak and beech), tree shoots, flowers, samaras (the key seeds of the field maple and sycamore), nuts, fruit, roots, cereals and sap tissue. Both species occasionally eat insects, eggs and young birds from nests although, on a larger scale, squirrels are not thought to be significant predators of avians. Grey squirrels will scavenge leftovers, eating southern fried chicken and ice cream cones from bins, as well as raiding bird feeders. Red squirrels spend most of their time in


108 I PC FEBRUARY/MARCH 2016


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