How Was the Eastern Grey Squirrel Introduced?
The origin of the eastern grey squirrel is unclear, although it has been present in Europe and North America for over a century. Its introduction is often blamed on human interference and conflict. In this article we will look at its ancestry, genetic diversity, and population dynamics. Finally, we will look at its impact on ecosystems. This article is meant to be a quick read and not a textbook or academic paper.
Origins
The Eastern Gray Squirrel is a native of North America. It has replaced the native red squirrel in many forests and parks. There are 20 Pleistocene fauna specimens of S. carolinensis, dating back to the late Irvingtonian period. During the early to middle Holocene, its body size was increased, and it was later reduced to its current size. The eastern gray squirrel has been a popular pet in the United States and in Europe for decades.
The Eastern Grey Squirrel varies in its diet. In summer, it eats winged maple seeds. Other food items include a variety of wild fruits and seeds. In autumn, the eastern grey squirrels feed on acorns, pine seeds, and other hard nuts. They also eat the eggs and young of birds. The Eastern Grey Squirrel is the only species that has the ability to live in multiple habitats at the same time.
Population dynamics
The study design involved examining recruitment of red-eyed eastern gray squirrels in two experimental red-grey sites: Borgo Cornalese, Piedmont; Hamsterley Forest, County Durham; and Parco Pineta, Lombardy. Each study site had a mean litter size of 2*75. Recruited red-eyed squirrels were younger than their grey counterparts, and the proportion of red-eyed squirrels decreased with increasing grey-eyed site density.
The carrying capacity of both red-eyed and grey-eyed squirrels varied across habitats and years, and may play a role in the duration and intensity of interspecific competition. In the Racconigi experiment, the red-eyed squirrels were still present 16 years after the grey-eyed squirrels colonized the forest, and the grey-eyed squirrels occupied the site for eight years. Both species showed similar patterns of migration, indicating that the gray-eyed squirrel population is not as abundant as previously thought.
Genetic diversity
Using microsatellite markers, researchers have studied genetic diversity of the eastern grey squirrel. In Ireland, genetic data was collected from eight sites. The study found that genetic diversity was moderate to low, with considerable inbreeding. One population was distinguished from others, possibly indicating that it was isolated from the rest of the range. In contrast, Ireland had a smaller founder population. Hence, these researchers hypothesized that the Irish populations are more genetically diverse than those of the U.S.A.
To determine ancestry, we used the ADMIXTURE method, which employs the population structure learned during initial unsupervised analysis. The genetic distances were assessed using five-fold cross-validation. This method identified ten distinct clusters within the population, each containing at least one squirrel. It was also possible to estimate ancestry within each cluster. For the remaining 99 squirrels, we used the QIAxcel system to size the PCR products.
Impact on ecosystems
According to Emily K. Gonzales, a graduate student in biology, “The introduction of eastern grey squirrels to British Columbia has caused widespread ecological damage.” Although the animals do not cause significant damage to crops, they are important agents of reforestation because they bury nuts, which germinate later, and help restore hardwood forests that have been destroyed by humans. However, these animals also pose a variety of nuisances to city dwellers, including destroying bulbs in gardens and driving birds away from bird feeders. However, their presence brings a great deal of pleasure to city dwellers as well. Those who love camping and the outdoors will love to see these creatures!
The gray squirrel’s population numbers have increased as a result of human intervention in the United States and Canada. This species has no native population in the United States and was introduced there in 1749, when the species was introduced to Pennsylvania from Europe. The introduction of eastern grey squirrels to the United States has led to bounties of 640,000 squirrels. However, this has not reduced the number of grey squirrels in the area, which suggests a long-term impact on ecosystems.
Economic importance
The eastern gray squirrel has displaced the native red in North America’s forests and parks. The species is found in twenty different Pleistocene specimens, dating back to the late Irvingtonian period. While it is predominantly an arboreal animal, it also engages in extensive terrestrial locomotion. This study is the first to quantify the economic importance of this species for a number of different ecosystems in North America.
Although once a major source of food for the Native Americans and colonists, the eastern gray squirrel continues to provide important foods to humans today. The species also has economic importance, especially in the Southern states, where 2.5 million are harvested each year. In Mississippi alone, the eastern grey squirrel is valued by nature enthusiasts at around $12.5 million per year. Though the species is not endangered or in danger of extinction, their plight does affect other animal species in the region.
Threat to native species
The threat to native species from the eastern grey squirrel is a well-documented issue. The grey squirrel is the most damaging invasive species in the US and has been introduced to other countries, including the UK, Ireland, Italy, and South Africa. Their rapid growth threatens trees, and they have displaced native red squirrels from their historic ranges. The gray squirrel is considered one of the world’s 100 worst invaders and is a prime candidate for eradication in many areas.
In addition to damaging homes and gardens, eastern grey squirrels can cause severe damage to trees, including nut and bark. Eastern gray squirrels pose a threat to native species, as they compete with native birds for food and cavities in trees. These animals can also eat bird eggs and nestlings. Because they are so prolific in the region, eastern grey squirrels are becoming a threat to native species and ecosystems.
How did the Eastern Grey Squirrel become introduced to North America?
Answer 1: They were brought over by humans in the 1800s from Europe as pets.
Jessica Watson is a PHD holder from the University of Washington. She studied behavior and interaction between squirrels and has presented her research in several wildlife conferences including TWS Annual Conference in Winnipeg.
