Vegetation of a Kirtland's warbler breeding area and 10 nest sites

Abstract

Early observers noted that the Kirtland's Warbler (Dendroica kirtlandii) required young jack pine (Pinus banksiana) stands of fire origin (Wood 1904, 1926; Barrows 1921; Leopold 1924; Wing 1933). Leopold (1924) observed that they nested in stands about 1 to 3 m tall and that the nest was usually within 3 dm (1dm = 0.1m) of the base of jack pine and well concealed by heavy ground vegetation. Wood (1926) further observed that they favored thick low branches, numerous small openings, and that as the stand matured, its value to the Kirtland's Warbler declined as shade destroyed the ground vegetation. More recently Mayfield (1953) defined their need for homogenous stands of jack pine between about 1.5 and 6 m high or about 7 to 20 years old, preferably in stands larger than 32 ha. In addition, 2 colonies were found in pure red pine (P. resinosa) which suggested that the pine life form rather than jack pine per se may be required. Mayfield (1962) also reported that all but a few colonies were located on the Grayling sand soil type. Anderson and Storer (1976) found 90% of nests which fledged warblers to be in stands larger than 80 ha. Although the general requirements of the Kirtland's Warbler have been characterized, a quantitative description of their vegetative requirements for breeding is lacking. This information is needed for management. We pilot-tested a scheme to sample the character of the vegetation in the general breeding habitat and around the nest sites, hoping to assess the adequacy of the method and improve it for later larger-scale studies.

Citation

Buech, Richard R. 1980. Vegetation of a Kirtland's warbler breeding area and 10 nest sites. The Jack Pine Warbler. 58(2): 58-72.