RESIDENT BIRD

A 'resident bird', in ornithology, is a bird that does not make seasonal migrations. Birds that do migrate are referred to as migratory birds.
For some bird species, a favorable environment, or food supply allows the birds to stay as a ''resident species'', until some non-typical weather, or food supply event causes a semi-permanent change. For example, in extremely harsh winters with low food supply, birds will migrate to warmer locations and feed opportunistically.