Squirrel enjoying a pine cone, near Phelps Lake in Wyoming
The danger of invasive species (such as this grey squirrel would be in the Netherlands) is a real one for our Dutch Red squirrels:
Eastern gray squirrels have been introduced to Italy and concern exists that it will displace the red squirrel from parts of the European continent.
The main factor in the eastern gray squirrel's displacement of the red squirrel is thought to be its greater fitness and, hence, a competitive advantage over the red squirrel on all measures. The eastern gray squirrel tends to be larger and stronger than the red squirrel and has been shown to have a greater ability to store fat for winter. The squirrel can therefore compete more effectively for a larger share of the available food, resulting in relatively lower survival and breeding rates among the red squirrel. Parapoxvirus may also be a strongly contributing factor; red squirrels are fatally affected by the disease, while the eastern gray squirrels are unaffected but thought to be carriers.
Squirrel enjoying a pine cone, near Phelps Lake in Wyoming
The danger of invasive species (such as this grey squirrel would be in the Netherlands) is a real one for our Dutch Red squirrels:
Eastern gray squirrels have been introduced to Italy and concern exists that it will displace the red squirrel from parts of the European continent.
The main factor in the eastern gray squirrel's displacement of the red squirrel is thought to be its greater fitness and, hence, a competitive advantage over the red squirrel on all measures. The eastern gray squirrel tends to be larger and stronger than the red squirrel and has been shown to have a greater ability to store fat for winter. The squirrel can therefore compete more effectively for a larger share of the available food, resulting in relatively lower survival and breeding rates among the red squirrel. Parapoxvirus may also be a strongly contributing factor; red squirrels are fatally affected by the disease, while the eastern gray squirrels are unaffected but thought to be carriers.