The Kirtland's Warbler (Setophaga kirtlandii), one of the rarest songbirds in North America, was first discovered when Charles Pease shot a migrant on 13 May 1851 on the farm of his father-in-law, Jared P. Kirtland, near Cleveland, OH. The new species was identified by Spencer Baird, who named it for the renowned Ohio naturalist (Baird 1852). The species' wintering grounds were discovered as additional specimens were collected from throughout the Bahamas, but it took 52 years before Norman Woods followed the lead of a graduate student from the University of Michigan and pursued the species along the Au Sable River in northeast Oscoda Co., MI, where he discovered the first nest of this elusive species in July 1903 (Wood 1904, Rapai 2012).
Throughout the first half of the twentieth century, the Kirtland's Warbler was studied by several of ornithology's finest naturalists, including N. Leopold, L. Walkinshaw, J. Van Tyne, H. Mayfield and others, who shared details of the species' life history. Their work laid the foundation for recovery, as the species became the victim of its own habitat specificity, and the conservation movement sought to save declining species.
The 1971 decennial census confirmed the population crash that ornithologists had predicted (Mayfield 1972), documenting the decline in population size from estimates of 1000 individuals to around 400. The large areas of dry, sandy soil with dense stands of young jack pine (Pinus banksiana), upon which the species depended, had declined owing to fragmentation and fire suppression, but the most imminent threat was nest parasitism by the Brown-headed Cowbird (Molothrus ater, Mayfield 1960, Walkinshaw 1983).
Owing to its natural rarity and apparent decline, Kirtland's Warbler was included on the first list of endangered species in 1967 under the Endangered Species Conservation Act (Office of the Secretary 1967). Following the enactment of the Endangered Species Act in 1973, the Kirtland's Warbler Recovery Team was created, and they produced a recovery plan in 1976 (Byelich et al. 1976). The plan established a recovery goal of 1000 breeding pairs distributed across the original breeding range of the species, and the revised plan (Byelich et al. 1985) identified and prioritized recovery strategies to achieve this goal, including habitat management, cowbird control, annual monitoring, research, and education. In the late 1980's, the population began to respond to the recovery efforts, and by 2012 the population had reached about 4000 individuals.
Kirtland's Warblers are now considered biologically recovered, but the species is dependent on perpetual management to establish the early successional habitat it needs, and to remove the cowbird threat on that restricted landscape. In fact, all five recovery strategies must continue, making the species entirely conservation-reliant (Scott et al. 2010). The Kirtland's Warbler Recovery Team is attempting to develop a public/private conservation partnership to safeguard annual management of the species after removal from the protection of the Endangered Species Act (Bocetti et al. 2012). The species has been above the recovery goal of 1000 breeding pairs for more than a decade, and as long as management continues, its future appears secure. Efforts to secure this rare and unique species may provide a conservation model for other conservation-reliant species as well.