Nesting Success of a Neotropical Migrant in a Multiple‐Use, Forested Landscape

Abstract

We studied the nesting success of an individually marked population of Kentucky Warblers (Oporornis formosus), a species that nests in disturbed and undisturbed forests, in a heterogeneous, managed forest site in the Shawnee National Forest in southern Illinois from 1992 to 1995. We examined the effects of forest stand type (clearcuts of various ages, tree plantations, and older forest) and distance from habitat edges on rates of nest predation and brood parasitism by Brown‐headed Cowbirds ( Molothrus ater). Brood parasitism levels gradually decreased from 60% to 3% ( nests) over a distance of 2 km from an agricultural edge proximal to a known cowbird foraging site (a pig feedlot), but they did not vary with distance from any other kinds of edges or with forest stand type. Rates of nest predation ( nests) did not vary with distance from any edges, but they were significantly lower in older forest than within even‐aged clearcuts, a tree plantation, and in successional vegetation adjacent to a residential facility. These results suggest that, even in fragmented landscapes with high overall levels of parasitism and nest predation, management practices within and immediately adjacent to forest tracts can affect the nesting success of some species, but not necessarily as a simple function of distance from edge. For the Kentucky Warbler, our results suggest that a management strategy that avoids even‐age silviculture and leaves core stands of older forest far from cowbird feeding areas can increase nesting success to levels similar to those measured in more forested landscapes.

Gamebird vulnerability to forest fragmentation: patch occupancy of the crested guineafowl (Guttera edouardi) in Afromontane forests

“…For forest avifauna this depends largely on mobility (Lens et al, 2002), home range/territory size (Rolstad, 1991) and migratory patterns (Morse & Robinson, 1999), as well as lifehistory traits and demography (Recher et al, 1987;Hansen & Urban, 1992;Warburton, 1997;Dale, 2001;Beier, Van Drielen & Kankam, 2002). Many traits have been identified as associated with local extinction proneness in populations of forest-dependent birds in fragmented landscapes.…”

Effects of Forest Edges on Ovenbird Demography in a Managed Forest Landscape

“…Similarly, King et al (1996) reported that Ovenbirds near edges compensate for increased predation by renesting. In contrast, Morse and Robinson (1999) found that Kentucky Warbler (Oporornis formosis) productivity is lower in agricultural edge than interior areas.…”

“…Many studies have compared habitats that contrasted strongly in terms of vegetation structure and composition or fragment size. Few studies have examined how proximity to edge influences habitat quality in a relatively unfragmented forest landscape (although see King et al 1996King et al , 1998aMorse & Robinson 1999).…”

“…The majority of these models focus on agricultural landscapes containing woodlots of various sizes. Less is known about the effects of anthropogenic forest edges on nesting density, reproductive success, and other demographic parameters that also may affect birds in landscapes dominated by forest cover (King et al 1996(King et al , 1998Donovan et al 1997;Morse & Robinson 1999).…”

Habitat Selection under Temporal Heterogeneity: Exorcizing the Ghost of Competition past

“…Schmidt and J. Goheen, unpublished manuscript). Habitats often have predictably higher quality, on average, than others (wintering habitat: Marra et al 1998;breeding habitat: Holmes et al 1996, Morse andRobinson 1999). Birds may therefore disperse between habitat types between and/or within years, biasing settlement toward higher quality habitats.…”