A recent annual survey of the federally endangered Kirtland's warbler shows its population still remains near an all-time high.

The bird is unique to Michigan because 98 percent of the entire population breeds within the state.

Biologists, researchers and volunteers observed 2,004 singing males during the official 2013 survey period, down from 2,063 males observed in 2012.

In 1974 and 1987, when the lowest survey numbers were recorded, only 167 singing males were found.

Estimates of the breeding population are obtained by doubling the number of singing males recorded.

This year, singing males were found in 12 northern Lower Peninsula counties and six Upper Peninsula counties. 21 additional singing males were observed outside Michigan in Wisconsin and Ontario.

The Kirtland's warbler survey is conducted each year in a joint effort between the Michigan Department of Natural Resources, U.S. Forest Service, U.S. Fish and Wildlife Service, Michigan Department of Military and Veterans Affairs, Michigan Audubon Society and numerous citizen volunteers.