The U. S. Forest Service notes that the fire suppression policies of the last century were as damaging to the Kirkland's warbler population as DDT was to the bald eagle. How can extinguishing a wildfire be a listing factor to this bird's populations? All BUT ONE could apply.
Responses
A Fire removes plants that compete with jack pines for forest space.Fire removes plants that compete with jack pines for forest space.
B Fire suppression had allowed the jack pine forests to become too old for the birds to use as nesting sites.Fire suppression had allowed the jack pine forests to become too old for the birds to use as nesting sites.
C Fires effectively remove competing bird species the area. Without periodic wildfires, Kirkland's warbler is outcompeted for food.Fires effectively remove competing bird species the area. Without periodic wildfires, Kirkland's warbler is outcompeted for food.
D Kirkland’s warblers nest in stands of young jack pines. Heat from the wildfires is needed to open cones to release seeds to keep rejuvenating young tree stands.