The Michigan Department of Natural Resources and Environment (MDNRE) has released their annual survey information regarding the endangered Kirtland's Warbler.

Biologists, researchers and volunteers in Michigan observed 1,733 singing males during the official 2010 survey period.  The study is conducted each year in the second and third weeks of June when the birds establish their nesting territories.  Only the males sing, so estimates are made on the assumption each male has a mate.

As the amount of habitat has stabilized, the population of warblers has stabilized in the core of the range: northern Michigan's jack pine barrens ecosystem. The warblers nest on the ground and typically select nesting sites in stands of jack pine between four and 20 years old. 

The population has not increased or decreased by more than 5 percent since 2007. The lowest numbers were recorded in 1974 and 1987, when only 167 singing males were found. The highest numbers were in 2009 when 1,813 males were observed.