Goshawk increase could help regulate Grey Squirrel
THE increase of Eurasian Goshawk in Britain could help regulate numbers of the nonnative Grey Squirrel, according to new research.
Grey Squirrel is native to eastern North America but was introduced by humans to Britain in the early 20th century. In areas where it is present, it outcompetes the smaller, native Red Squirrel, which has a less varied diet.
Indeed, it is estimated that since the introduction of Grey Squirrel to British shores, the
Red Squirrel population has plummeted from some 3.5 million to 120,000. Red Squirrel is now localised in Britain and absent from much of England.
Grey Squirrel has a few natural predators, including mustelids, domestic cats and birds of prey – especially Eurasian Goshawk.
Eurasian Goshawk was extinct in Britain by the end of the 19th century and was very rare even in the mid-20th century. However, numbers have gradually reestablished and, in the past decade, have veritably boomed. For example, hundreds of pairs are now thought to be in the New Forest, a historic hot-spot for the raptor. And due the increase in goshawks, it is now thought that the British population of Grey Squirrel can be controlled in a natural way.
In an article published in
2023 in the Quarterly Journal of Forestry, the journal of the Royal Forestry Society, the installation of camera traps near goshawk nests between 2017 and 2022 by the Gloucestershire Raptor Monitoring Group showed that squirrels made up an important part of the diet of the birds.
Gloucestershire is home to more than 100 pairs of Eurasian Goshawk. In some of the nests studied, Grey Squirrels made up more than half of the prey that were brought by adults to feed young – far more even than corvids and Woodpigeons, which also make up a significant part of British goshawks’ diets.
Reference
Field, A. 2023. Goshawk as predators of gray squirrel in Gloucestershire. Quarterly
Journal of Forestry. Royal Forestry Society. Available online at www.glosraptors.co.uk.