Title: A test of 3 models of Kirtland's warbler habitat suitability

Author: Nelson, Mark D.; Buech, Richard R.

Year: 1996

Publication: Wildlife Society Bulletin. 24(1): 89-97.

Abstract: We tested 3 models of Kirtland's warbler (Dendroica kirtlandii) habitat suitability during a period when we believe there was a surplus of good quality breeding habitat. A jack pine canopy-cover model was superior to 2 jack pine stem-density models in predicting Kirtland's warbler habitat use and non-use. Estimated density of birds in high- and medium- class habitat was higher for the canopy-cover model (4.4 birds/100 ha in high class, 2.9 birds/100 ha in medium class) than for either stem-density model (2.2-2.5 birds/100 ha in high class, 1.2-1.7 birds/100 ha in medium class). Lower bird density was estimated in low- class habitat for the canopy-cover model (0.3 birds/100 ha) than for the stem-density models (0.7 birds/100 ha). Overall estimated density of male Kirtland's warblers on the Mack Lake wildfire area was 1.3-1.5 birds/100 ha. For all 3 models, Kirtland's warblers selected territories that contained 16-27% low-, 23-49% medium-, and 32-50% high- class suitability habitat. There was no correlation between territory size and proportion of territory in each habitat class. Even though many male Kirtland's warblers included low- class habitat in their territories, >97% of those birds also included medium- or high-class habitat. This study confirmed the importance of high stem density and high canopy cover to Kirtland's warbler habitat occupancy of young jack pine habitat regenerated from wildfire. However, low-class stem-density or low-class canopy-cover habitat also was included in territories, even though additional high- and medium-class habitat was available and apparently unoccupied. Therefore, habitat managed for Kirtland's warblers should contain medium- and low- as well as high-class habitat patches in juxtaposition.