For food:
* Other squirrels: Different squirrel species often compete for food and territory, particularly when resources are scarce.
* Birds: Many birds, especially those that eat nuts and seeds, are direct competitors with squirrels. Examples include chickadees, nuthatches, and woodpeckers.
* Rodents: Rats, mice, and other rodents compete for similar food sources like seeds and nuts.
* Deer: Deer can be significant competitors for acorns and other nuts.
For shelter:
* Birds: Some birds, especially cavity nesters, may compete with squirrels for nesting sites.
* Other mammals: Raccoons, opossums, and other small mammals may compete for tree cavities and dens.
For territory:
* Other squirrels: As mentioned before, squirrels often defend territories and compete with other squirrels of the same species, especially during mating season.
* Predators: Predators like hawks, owls, and snakes can also influence squirrel populations by preying on them, indirectly affecting competition.
Factors affecting competition:
* Habitat: In urban areas, squirrels may compete more with humans for food, while in forests, competition with other squirrels, birds, and rodents is more significant.
* Season: Competition can vary depending on the time of year and availability of resources.
* Species: Different squirrel species have different dietary preferences and habitat requirements, which influences their competitors.
It's important to note that competition isn't always a direct fight. It can also be subtle, like squirrels choosing different foraging strategies or adapting their behaviour to avoid conflict. Competition also plays a role in shaping the evolution and distribution of species.