Hooded Warbler
Ecoregional Scale Conservation Planning

Made possible through a partnership with the National Wetlands Research Center

Carolina Chickadee (Poecile carolinensis)

The Carolina chickadee is a resident species of the southeastern United States. Although populations have been stable in the CH, Carolina chickadees have declined ~2 percent annually over the last 40 years in the WGCP Table 005 (Table 005) . The species is classified as a Bird of Conservation Concern requiring critical recovery and immediate management activities in the WGCP (regional combined score = 19) and CH (regional combined score = 19), respectively Table 001 (Table 001) .

Relative abundance of Carolina Chickadee, derived from Breeding Bird Survey data, 1994 - 2003.
image courtesy of www.whatbird.com

Natural History:

The Carolina chickadee is a generalist species that breeds in a wide variety of forest types across a broad spectrum of landforms (Mostrom and others 2002). Carolina chickadees nest in cavities of live and dead trees within multilayered forests containing well-developed shrub, midstory, and overstory canopies (Hamel 1992). Carolina chickadee abundance declines following the reduction of hardwoods in pine stands, likely as a result of the loss of midstory trees (Provencher and others 2002). Nest success and adult survival is positively correlated with woodlot area, but is lower on edges regardless of patch size (Doherty and Grubb 2002). Nest destruction by house wrens is a major cause of nest failure in areas where the two species’ ranges overlap. Territories sizes range from 1.6-2.4 ha.

Model Description:

The Carolina chickadee model contains four parameters affecting density:

  • landform
  • landcover
  • successional age class
  • snag density

The first suitability function combines landform, landcover, and successional age class into a single matrix (SI1) that defines unique combinations of these classes Table 048 (Table 048) . We directly assigned suitability index scores to these combinations based on vegetation and successional age class associations of Carolina chickadees reported in Hamel (1992).

We included snag density (SI2) as a model parameter because of the importance of nest and roost cavities for chickadees, a secondary cavity nester. Although data for Carolina chickadees was not directly available, both Rumble and Gobeille (2004) and Sedgwick and Knopf (1990) observed black-capped chickadees in habitats with 6 snags/ha Table 049 (Table 049) . Therefore, we assumed stands with ≥6 snags/ha were representative of optimal habitat. Because chickadees can utilize cavities in live trees, we assumed stands with no snags were not necessarily non-habitat and assigned them a suitability index score of 0.030. We fit a logistic function through these data points to quantify the snag density-habitat suitability relationship Figure 025 (Figure 025) .

We calculated the overall suitability index score as the geometric mean of the two individual functions:

Overall SI = (SI1 * SI2)0.500