Kirtland's Warbler Use of Red Pine

The endangered Kirtland’s warbler has long been considered an extreme habitat specialist, preferring to breed exclusively in dense young jack pine stands in northern Michigan.As the warbler’s numbers have increased and the species is being considered for removal from the US Endangered Species List, Kirtland’s warblers are being observed using and nesting in stands of red pine with similar characteristics of age and structure. A more economically valuable tree than jack pine, red pine, if shown to provide acceptable breeding habitat for the Kirtland’s warbler, has the potential to vastly increase management options for further recovery of this species, and provides a pathway for increased engagement of the forest products industry in the conservation of the Kirtland’s warbler. The Au Sable Institute is investigating the comparative densities and reproductive success of Kirtland’s warbler in stands of jack pine and red pine with similar characteristics of structure and density in Claire, Oscoda, and Ogemaw Counties in northern lower Michigan. To date, Institute researchers have found similar densities and nesting success rates in both stand types. If such preliminary results are confirmed by additional investigation, red pine could provide critical additional breeding habitat as the Kirtland’s warbler’s range expands in its current phase of population growth.