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We document the first confirmed cases of polygyny and double brooding in the Eastern Wood-Pewee (Contopus virens). During an intensive study of the effects of shelterwood harvesting on canopy-nesting songbirds in southeastern Ohio, 2007–2010, we color-banded 79 Eastern Wood-Pewees and monitored 237 pewee nests. In 2007, we confirmed a color-banded male provisioning at two concurrently active nests; the male was polygynous in at least two consecutive years. In 2009, we observed an unbanded female feeding fledglings and subsequently shaping a nest from which young had recently fledged; the female successfully fledged two broods from the same nest. In addition to confirmed observations, we identified several other probable cases of polygyny and double brooding. In our upland oak system, we estimated rates of polygyny from 6–22% with the greatest occurrence of polygyny during a dry spring in 2007; rates of double brooding may have been as high as 6–12%. Males appeared to benefit from polygyny, becaus...

Studies of habitat selection are often of limited utility because they focus on small geographic areas, fail to examine behavior at multiple scales, or lack an assessment of the fitness consequences of habitat decisions. These limitations can hamper the identification of successful site-specific management strategies, which are urgently needed for severely declining species like Cerulean Warblers (Setophaga cerulea). We assessed how breeding habitat decisions made by Cerulean Warblers at multiple scales, and the subsequent effects of these decisions on nest survival, varied across the Appalachian Mountains. Selection for structural habitat features varied substantially among areas, particularly at the territory scale. Males within the least-forested landscapes selected microhabitat features that reflected more closed-canopy forest conditions, whereas males in highly forested landscapes favored features associated with canopy disturbance. Selection of nest-patch and nest-site attributes by female...

Interest in regenerating oaks (Quercus spp.) has promoted use of partial harvesting techniques that create an open forest structure. From 2007 to 2009, we studied songbirds in mixed-oak forests in southeastern Ohio, comparing shelterwoods recently harvested to 50% stocking and closed-canopy mature second-growth. We surveyed birds using distance-based methods (56 line transects in 18 stands at 4 forests). We intensively investigated suitability of shelterwoods for canopy-nesting species by examining habitat preferences, as measured by settlement patterns, age distributions, and site fidelity; we also examined nesting success. Several midstory and ground-nesting species were 26–73% less abundant in shelterwood than unharvested stands, whereas shrub-nesting species increased >100% several years post-harvesting. Canopy-nesting species were 31–98% more abundant in shelterwoods, but cerulean warbler (Setophaga cerulea) responses varied by forest. Patterns of settlement and site fidelity were generally similar among stands. Proportions of young males were actually greater for several species in shelterwood than unharvested stands, which may have been a consequence of young birds colonizing newly created (or improved) habitat. Even in our predominantly forested study system, nesting success (>700 nests) was low, ranging from 15% to 19% for yellow-throated vireos (Vireo flavifrons) and cerulean warblers, to 27–36% for scarlet tanagers, blue-gray gnatcatchers (Polioptila caerulea) and eastern wood-pewees (Contopus virens). However, nest survival did not differ between shelterwood and unharvested stands, possibly because numbers of avian predators did not change with harvesting. Despite increased numbers of brown-headed cowbirds (Molothrus ater) in shelterwoods, only 2% of canopy nests in which young could be identified were parasitized. Although these results suggest shelterwood harvests containing abundant overstory trees can provide short-term breeding habitat for canopy songbirds, long-term responses of birds to partial harvesting may differ from those documented here depending on different management options employed. Management for oak regeneration will typically remove all overstory trees later in the cutting cycle, initially resulting in loss of nesting substrates and hence breeding habitat for canopy songbirds. © 2011 The Wildlife Society.

Although oaks (Quercus spp.) have historically dominated many forests in eastern North America, forest composition is changing due to anthropogenic impacts on disturbance regimes. Silvicultural practices, such as partial harvesting, are one component of management to promote oak regeneration. From 2007 to 2009 our research examined nest-site selection and nesting success for a guild of five canopy songbirds in upland mixed-oak forests in southeastern Ohio, USA. We monitored >700 nests across three state forests in both open canopy shelterwood stands harvested to approximately 50% stocking, and closed-canopy mature second-growth. Habitat attributes, including topography, canopy structure, and floristics, were measured at nest sites and random plots ⩽100 m from nests representing microhabitat available within the territory. Canopy songbirds selected specific topographic microclimates: Eastern Wood-pewees (Contopus virens) nested on xeric ridgetops, Blue-gray Gnatcachers (Polioptila caerulea) favored valleys, and Cerulean Warblers (Dendroica cerulea) preferred productive northeast-facing slopes. Nest sites differed among species in terms of concealment, nest support, topographic position on the slope, and basal area of trees >38 cm dbh. Four of the five focal species selected Quercus alba as the nest substrate more than twice as much as available, and three species avoided Quercus rubra. Daily survival rates of nests were negatively associated with basal area of red oak species (both Quercus velutina and Q. rubra) for several species individually and across the canopy-nesting guild. Additional factors related to success included time of season for Eastern Wood-pewees, nest age for Cerulean Warblers, and concealment and size of the support branch for Scarlet Tanagers (Piranga olivacea). In the long-term management for oak regeneration could benefit canopy songbirds, but our results indicate that white oaks, especially Q. alba, may be preferable to red oak species.

We studied the nesting of the Louisiana Waterthrush (Seiurus motacilla) in western Pennsylvania from 1996 to 2008. Eight of 143 pairs (5.6%) that successfully fledged young from their first nest attempted a second brood, the first cases of double brooding reported for this species. Given the potential for double brooding to increase annual productivity, its infrequency suggests strong costs offsetting this life-history strategy. Molting is a late-season constraint that may influence the occurrence of double brooding in this migratory species. The waterthrushes' nesting season extended from 14 April to 30 July. A single nesting cycle, from clutch initiation through post-fledging care, encompassed 48–55 days. The mean date of clutch initiation for first attempts of single-brooded pairs was 5 May, with at least two thirds of pairs renesting if their first nest attempt failed; the mean date of initiation of second clutches was 25 May. The mean dates of first and second clutches of eight double-brood...

We used Mayfield logistic regression and an information-theoretic approach to examine habitat characteristics associated with nesting success of Wood Thrushes (Hylocichla mustelina) across an urban to forested gradient in southwestern Pennsylvania in 2003 and 2004. Both nest placement and number of understory stems provided equally plausible models. Mayfield success was 20% higher for nests >3 m above ground level while dense understory was associated with low nest height. Wood Thrush nests in the forest interior averaged 2 m higher with a third less understory than edge nests. Urbanization and distance to the forest edge were not useful predictors of Wood Thrush nest success. The analysis was confounded by low breeding density at the most urbanized sites, but we found moderate success (42%, n = 63) across a fragmented landscape with minimal core forest area. Interior nests in a large contiguous forest were twice as successful (60%, n = 31) compared to edge nests (25%, n = 33) adjacent to a small...

Summary 1. We compared breeding ecology of the Louisiana waterthrush (Seiurus motacilla) on acidified and circumneutral streams in the Appalachian Highlands of Southwestern Pennsylvania from 1996 to 2005. 2. Headwater streams impacted by acid mine drainage and/or acidic precipitation showed reduced pH (range 4.5–5.5) compared to four circumneutral streams (pH c. 7). Acid-sensitive taxa, including most mayflies (Ephemeroptera), were almost completely absent from acidified streams, whereas several acid-tolerant taxa, especially stonefly (Plecoptera) genera Leuctra and Amphinemura, were abundant. 3. Louisiana waterthrush breeding density (c. 1 territory km−1) was significantly reduced on acidified streams compared to circumneutral streams (>2 territories km−1). Territories on acidified streams were almost twice as long as on circumneutral streams. Territories usually were contiguous on circumneutral streams, but they were often disjunct on acidified streams. Breeding density declined on one acidified stream that we studied over a 10-year period. 4. Clutch initiation was significantly delayed on acidified streams, on average by 9 days in comparison to circumneutral streams, and first-egg dates were inversely related to breeding density. Birds nesting along acidified streams laid smaller clutches, and nestlings had shorter age-adjusted wing lengths. Stream acidity had no effect on nest success or annual fecundity (fledglings/female). However, the number of young fledged km−1 was nearly twice as high on circumneutral streams as on acidified streams. 5. Acidified streams were characterized by a younger, less site-faithful breeding population. Individuals were less likely to return multiple years to breed, allowing inexperienced breeders to settle on acidified streams. Pairing success was lower on acidified streams, and we observed four cases of waterthrushes emigrating from territories on acidified streams to nearby circumneutral streams in the following year. 6. We conclude that acidified headwaters constitute lower quality habitat for breeding Louisiana waterthrush. However, breeding birds can apparently compensate for reduced prey resources to fledge young on acidified streams by increasing territory size, foraging in peripheral non-acidified areas, and by provisioning young with novel prey.