Influence of habitat amount, arrangement, and use on population trend estimates of male Kirtland’s warblers

Using an integrated recording and sound analysis system to search for Kirtland's Warbler (<em>Setophaga kirtlandii</em>) in Ontario

“…Typical Kirtland's Warbler habitat in the core of the species range in Michigan's Lower Peninsula is homogeneous stands of 6-23-yearold Jack Pine that have regenerated after wildfire or that have been planted and managed specifically for Kirtland's Warbler (Walkinshaw 1983;Kashian et al 2003;Donner et al 2008). However, Kirtland's Warblers have also been reported nesting in Red Pinedominated plantations in Wisconsin (Anich et al 2011) and in mixed Jack Pine-Red Pine stands at Garrison Petawawa in Ontario (Richard 2013).…”

“…As a result of habitat management, aggressive control of Brown-headed Cowbird (Molothrus ater), and wildfires in the species' core breeding range, the Michigan population expanded considerably starting in the early 1990s (Probst and Weinrich 1993;Kepler et al 1996;Donner et al 2008), leading to an extension of the species' range. Small numbers of Kirtland's Warblers have nested in Michigan's Upper Peninsula since 1995 (Probst et al 2003) and in Wisconsin since 2007 (Trick et al 2008).…”

How well does Kirtland's warbler management emulate the effects of natural disturbance on stand structure in Michigan jack pine forests?

“…Widespread harvesting and planting of jack pine for Kirtland's warbler habitat has largely replaced wildfire as the dominant mode of stand initiation in this area. For example, Donner et al (2008) found that warbler plantations made up over 80% of the 5-23-year old jack pine stands on public lands in 2004. Harvesting and planting has clearly been demonstrated as an effective method of creating habitat for this single endangered species (Probst and Weinrich, 1993;Donner et al, 2008), but our results demonstrate that this management has resulted in marked differences in other ecosystem components at the stand level.…”

“…(Donner et al, 2008). In response to this decline, and because of the risks of prescribed fire to human safety and infrastructure demonstrated by the Mack Lake Fire of 1980 (Simard et al, 1983), in 1981 state and federal forest managers began an extensive program of harvesting and planting jack pine to restore this early-successional habitat.…”

“…In response to this decline, and because of the risks of prescribed fire to human safety and infrastructure demonstrated by the Mack Lake Fire of 1980 (Simard et al, 1983), in 1981 state and federal forest managers began an extensive program of harvesting and planting jack pine to restore this early-successional habitat. This intensification of plantation management has been a great success in terms of promoting warbler populations (Solomon, 1998;Donner et al, 2008); however, it raises the possibility that extensive management, narrowly focused on maximizing suitable habitat for a single endangered species, could have the unintended consequence of driving stand structure towards conditions that differ significantly from what natural disturbance would produce. According to Lindenmayer and Recher's (1998) definition of sustainable forest management, structure is one of the three important components that need to be maintained within the bounds of normal disturbance regimes, along with species composition and the rate of ecological processes and functions.…”