Not every bird is treated the same. The federal Migratory Bird Treaty Act applies only to migratory bird species native to the United States, and the U.S. Fish and Wildlife Service lists the house sparrow, European starling and rock pigeon among species it does not cover. Colorado Parks and Wildlife also classifies starlings and house sparrows as invasive species in the state.
That makes identification the first step. Starlings, which use trees, buildings and other human structures for nesting, cause most vent problems. Northern flickers, common in the Fort Collins area, are native woodpeckers, and the City of Fort Collins notes that they are protected by strict federal and state laws, so only non-lethal tactics may be used to exclude them unless a federal permit is obtained.
Timing follows the nesting season. Starlings pair off from late February through March and usually lay eggs in mid-April, and their young leave the nest at about 21 days old. Flickers announce themselves each spring by drumming on metal gutters and chimney flashing.
For your home, that means we identify the bird and check its nest status before any opening is closed, and we choose an exclusion method that suits both the species and the building.