
A male Kirtland's warbler is shown singing while perched.
Michigan Department of Natural ResourcesThe once-endangered Kirtland's warbler is continuing to grow in population since being taken off the endangered species list two years ago.
In a survey conducted in June of this year by state and federal agencies and volunteers, the warblers are estimated at 2,245 pairs. This estimate is more than double the recovery goal for the species.
“The power of partnership continues to yield excellent results for the Kirtland’s warbler after coming off the endangered species list,” U.S. Fish and Wildlife Service Regional Director Charlie Wooley said.
The survey was conducted by searching for males who are defending nesting territories. These males are presumed to have a mate, indicating the existence of a pair.
The survey took place in jack pine forests managed by the Michigan Department of Natural Resources, U.S. Forest Service, and U.S. Fish and Wildlife Service largely in the northern Lower Peninsula.
Kirtland’s warblers build their nests on the ground in young, dense jack pine stands in the Great Lakes region, specifically Michigan, Wisconsin and Ontario. With wildfires suppressed in these areas, the nesting areas are encouraged by harvesting the mature jack pines for logging and then planting jack pine seedlings in those areas.
A total of 1,114 males were located in the Huron National Forest and another 994 were found in the northern Lower Peninsula. Two were found in Lake County in the Manistee National Forest in an area not established for Kirtland’s warbler breeding, marking the first time they have been found there since 1977.
The Upper Peninsula also saw a record number of warblers — 67 were found this year throughout the U.P. on state and national forest lands.
“The number of singing males was above what we expected,” Phil Huber, wildlife program manager for the Huron-Manistee National Forests in Cadillac, said. “It’s really gratifying to see this species doing so well, especially compared to the population lows we observed in the 1970s and early 1980s when 200 singing males was the average.”
These recovery numbers have been gradually increasing since 1987 after a record low of 167 pairs.
For more information on the Kirtland’s warbler, visit the U.S. Fish and Wildlife Service website.