Northeastern Naturalist 690 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 22001155 NORTHEASTERN NATURALIST 2V2(o4l). :2629,0 N–7o0. 34 American Woodcock and Golden-winged Warbler Abundance and Associated Vegetation in Managed Habitats Marja H. Bakermans1,*, Cassandra L. Ziegler2, and Jeffery L. Larkin2 Abstract - Vermivora chrysoptera (Golden-winged Warbler) and Scolopax minor (American Woodcock, hereafter, Woodcock) are 2 young-forest-dependent species of eastern North America that are experiencing population declines due to loss of breeding habitat. The goals of our study were to compare avian abundance and habitat similarities and differences in sites used by the 2 species. A portion of our survey plots were manipulated under Woodcock or Golden-winged Warbler habitat prescriptions in managed shrublands, and others were on regenerating timber-harvest sites. In north-central PA, we compared Woodcock abundance in 10-ha experimental plots assigned to one of 3 habitat prescriptions: uncut controls, Woodcock strip plots, and Golden-winged Warbler mosaic plots. We also quantified vegetation characteristics in each 10-ha study plot. Woodcock density was higher in the strip (4.8 males/10 ha) and mosaic (5.1 males/10 ha) plots compared to the uncut reference plots (3.3 males/10 ha). Woodcock density was negatively correlated with sapling cover in the north-central PA study plots. In regenerating timber harvests in northeastern PA, we demonstrated that vegetation characteristics overlap regardless of whether we detected only Woodcock or both species. Mean basal area of harvested stands with only Woodcock (i.e., 11.5 m2/ha) was greater than the mean basal area in stands used by Golden-winged Warbler (8.4 m2/ha). Our results suggest that creation of young forests at the stand level using either the Woodcock or Golden-winged Warbler habitat guidelines has benefits for both species. However, the Golden-winged Warbler is less flexible in the density of herbaceous cover and residual trees it requires. We recommend that in areas where the 2 species coexist, the Golden-winged Warbler guidelines be implemented to benefit both species. Introduction Vermivora chrysoptera (L.) (Golden-winged Warbler) is a neotropical songbird that nests in young forests and shrublands embedded within the forest-dominated landscapes of eastern North America. The species has experienced significant population declines (8.5% annually since 1966; Larkin and Bakermans 2012, Sauer et al. 2014) throughout its Appalachian Mountains breeding range and has been the focal species of recent conservation efforts, including the National Resources Conservation Service’s Working Lands for Wildlife program (Bakermans et al. 2011, Roth et al. 2012, USDA 2012). Several factors have been implicated in the decline of Golden-winged Warbler populations, including competition and hybridization with Vermivora cyanoptera (L.) (Blue-winged Warbler), Molothrus ater (Boddaert) (Brown-headed Cowbird) parasitism, and habitat loss (Buehler et al. 2007, Confer 1Department of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609-2280. 2Department of Biology, Indiana University of Pennsylvania, 114 Weyandt Hall, Indiana, PA 15705-1001. *Corresponding author - mbakermans@ wpi.edu. Manuscript Editor: Daniel M. Keppie Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 691 et al. 2003, 2011, Vallender et al. 2007). However, there is general agreement within the scientific community that breeding-habitat loss likely contributes most to the species’ decline (Buehler et al. 2007). Management practices for Golden-winged Warbler can vary widely depending on geographic location and local land use (Roth et al. 2012). Breeding habitat is created by prescribed fire and wildfires, timber harvesting, prescribed grazing, maintenance of shrub/scrub areas and utility rights-of-way, and occurs naturally in shrubland and wetland communities (Confer et al. 2011). However, the availability of young forest for breeding Golden-winged Warblers has declined because of decreased rates of farm abandonment, changes in forest-management practices, and suppression of natural disturbances (Askins 2001, DeGraaf and Yamasaki 2003, Lorimer and White 2003). Scolopax minor Gmelin (American Woodcock, hereafter, Woodcock) is another young-forest-dependent species that has suffered significant population declines (McAuley et al. 2013), and singing-ground surveys estimate that populations experienced an annual 0.8% decline in eastern North America from 1968–2012 (Cooper and Rau 2012). Golden-winged Warblers breed in both upland and wetland communities, thus, there is potential for Golden-winged Warbler habitat management to benefit Woodcock and vice versa. A better understanding of how these 2 species use managed areas should help maximize multi-species management. Our goal was to determine if management (i.e., shrubland mowing, timber harvesting) for Golden-winged Warbler and Woodcock can be integrated in areas of range overlap. First, we examined abundance of American Woodcock in response to 3 treatments in managed shrubland communities: control plots, mowed-strip plots (Woodcock guidelines; Williamson 2010), and mowed-mosaic plots (Golden- winged Warbler guidelines; Aldinger and Wood 2014). Next, we examined differences and similarities in vegetation features in regenerating timber harvests where we detected Woodcock, Golden-winged Warbler, or both species. Study Area Managed shrublands We conducted surveys of Woodcock abundance and associated vegetation in managed shrublands of Bald Eagle State Park (BESP) in north-central Pennsylvania in 2011. BESP consists of 2387 ha of forests, fields, and wetlands surrounding a 700-ha lake at the base of Bald Eagle Mountain. BESP lies between 2 physiographic provinces: the Mountainous High Allegheny Plateau and the Ridge and Valley (Fenneman 1938, Sevon 2000). Elevation ranges from 210 m to 245 m. Habitat at BESP consists of areas dominated by small woodlots and shrublands comprised of Lonicera tatarica L. (Tartarian Honeysuckle), Elaeagnus umbellata Thunb. (Autumn Olive), Rosa multiflora Thunb. (Multiflora Rose), Alnus incana (L.) Moench (Speckled Alder), Cornus amomum Mill. (Silky Dogwood), Cornus racemosa Lam. (Gray Dogwood), and Viburnum dentatum Fernald (Arrowwood) (Frantz et al., in press). Early-successional habitat management to benefit Woodcock had been the focus at BESP since 2002. Specifically, there were several areas of the park that were Northeastern Naturalist 692 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 managed for Woodcock using strip mowing (hereafter, strip plots; Williamson 2010). The strip plots we surveyed (n = 3) were each 10 ha in size and consisted of several 30-m-wide strips (see Supplemental File 1, available online at http://www. eaglehill.us/NENAonline/suppl-files/n22-4-N1335-Bakermans-s1). Each plot was completely mowed every 3–5 years beginning in 2002 in a rotation such that all vegetation in the 10-ha plot was ≤16–20 y old, including trees. One plot had been mechanically treated during the winter of 2004, a second plot was mowed in 2008, and a third plot was mowed in 2010. The third plot was treated in a manner similar to those in 2004 and 2008, but crews left a few scattered trees and patches of shrubs throughout the plot, per BESP management’s request. We also surveyed 10-ha plots (n = 4) in BESP that had been treated based on guidelines from a concurrent study on Golden-winged Warbler habitat characteristics in BESP (Aldinger and Wood 2014). Specifically, these plots were mowed during the winters of 2009–2010 (n = 3) and 2010–2011 (n = 1) in a manner that resulted in a patchy mosaic of tree, shrub, and herbaceous cover throughout each 10-ha site (hereafter, called mosaic plots; see Supplemental File 1, available online at https://www.eaglehill.us/NENAonline/suppl- files/n22-4-N1335-Bakermans-s1). We also surveyed Woodcock and associated vegetation in 3 unmowed reference plots (hereafter, control plots) in BESP. Control plots were each 10 ha in size, adjacent to treatment plots, and not managed during our study. As such, control plots consisted of dense shrub thickets with scattered individuals or patches of trees (see Supplemental File 1, available online at http:// www.eaglehill.us/NENAonline/suppl-files/n22-4-N1335-Bakermans-s1). All plots were within a 9.5-km-long area on the western side of a reservoir within BESP, at the same elevation, and subject to the same moisture gradients. Timber management The timber-management study area (total area > 40,000 ha) was located in Monroe and Pike counties, PA, in the Pocono Mountain region on State Game Lands 127, Delaware State Forest (DESF), and a private hunting club adjacent to DESF. Our site was located in the Appalachian Glaciated Low Plateau physiographic province (Fenneman 1938, Sevon 2000) and was characterized by rounded hills and valleys with underlying shale, sandstone, and siltstone. Mean elevation for timber harvests surveyed in this region was 415 m (range = 275–563 m) and mean stand size was 14.4 ha (0.9 ha SE). The forested landscape was dominated by older trees (80+ years post-harvest) with wetlands and developed areas scattered throughout. Forest cover varied and included Quercus ilicifolia Wangenh. (Scrub Oak ), oakheath, northern hardwood forests and swamps, glacial bogs, and conifer swamps (Stoleson and Larkin 2010). We randomly selected existing timber harvests in the area based on time since harvest (i.e., 0–20 years) and residual basal area (RBA; 0–18 m2/ha). All harvests surveyed in this study (n = 63) were created through standard commercial operations, and none were planted restorations. Timber harvests contained regenerating cuts, log landings, scattered residual canopy trees, and skid trails that were embedded within the harvest, thus, providing potential courtship, nesting, brooding, and roosting areas for Woodcock. Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 693 Methods Avian surveys Managed shrublands. We quantified Woodcock abundance in 2 types of treatments— strip plots (n = 3) and mosaic plots (n = 4)— and in untreated control plots (n = 3). We used a modified singing-ground survey protocol (USFWS 2011) from 18 April to 5 May 2011 to survey 1 plot of each type on each survey night. Observers walked 2 transects that traversed each study plot length-wise. We surveyed each plot twice during the season, with visits 7–10 days apart, and averaged the number of birds detected. Survey start-time depended on sunset times and amount of cloud cover. That is, surveys began 22 minutes after sunset on evenings that were ≤75% overcast or 15 min after sunset if the sky was >75% overcast (USFWS 2011). We listened continuously for calling individuals while walking the transects, recorded all estimated locations on a plot map, and took care to avoid double-counting individuals. We made brief stops to count Woodcock if we heard more than 1 at a time. We did not record flight displays; rather, observers waited for individuals in flight to land and “peent” prior to recording location data. We did not quantify abundance of Goldenwinged Warblers at these sites because mosaic plots had recently been created and had not developed the vegetation features required by Golden-winged Warblers. Timber management. We conducted surveys for Woodcock and Golden-winged Warbler abundance in 17 regenerating timber harvests and surveyed an additional 46 harvests only for Golden-winged Warblers. We used a modified American Woodcock singing-grounds protocol and conducted surveys twice at each location from 15 April to 5 May 2011 (USFWS 2011). Timber harvests were located close enough to each other so that we could survey several in the same night. At each timber harvest, observers listened for 2 min and recorded the number of different Woodcock heard “peenting” in the stand. We conducted Golden-winged Warbler surveys from 10 May to 15 June in 2010 and 2011 via point-count methods (modified from Gregory et al. 2004). Each timber harvest had 1–2 point-count locations, and we randomly selected 1 of them to represent each stand in analyses. All observations occurred between sunrise and 1100 hours EST in favorable weather conditions (i.e., no heavy rain, high winds, or fog). We visited each point-count location 2–3 times per season with 4–7 days between surveys. We recorded each Golden-winged Warbler identified or encountered over a 10-min period. Visual confirmation of birds was important given the potential occurrence of Blue-winged Warblers and hybrids (e.g., Brewster’s Warbler [V. chysoptera x V. cyanoptera]; Gill 1980) using the same habitats. Thus, once the point count was complete, each observer used a Goldenwinged Warbler song playback (Cornell Lab of Ornithology, Ithaca, NY) until they positively identified each singing male. Vegetation surveys We followed a modified vegetation sampling protocol developed by the Goldenwinged Warbler Working Group (see Bulluck and Buehler 2008) and collected data on vegetation in both management systems based on its importance in previous studies (Bakermans et al. 2011, 2015; Bullock and Buehler 2008; Confer et al. 2003; Northeastern Naturalist 694 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 Dessecker and McAuley 2001; Klaus and Buehler 2001; Patton et al. 2010; Rossell et al. 2003; Straw et al. 1986). In managed shrubland sites (BESP study area), we measured vegetation in each 10-ha study plot using a systematic random-sampling design. We sampled vegetation at 100 points along 3–5 transects per 10-ha plot. Transects in the strip treatments were 25–40 m apart and arranged perpendicular to the mowed strips to avoid any potential for transects to run the length of a strip. At timber-management sites (Pocono Mountains study area), we quantified vegetation associated with each point-count location by positioning vegetation-sampling plots at the center of point-count locations. We sampled vegetation at ≥30 locations along 3 transects oriented in random directions 120° apart and extending 125 m from the plot center. In both management systems, we measured vegetation in 1-m- and 5-m-radius plots. Within each 1-m-radius plot, we measured percent cover of herbaceous plants (grasses and forbs), and woody plants >0.5m tall—shrubs (<1 cm diameter at breast height [DBH]), saplings (<10 cm dbh), and trees (≥10 cm dbh). At every 5th sampling point, we estimated RBA of canopy trees by species using a 10-factor prism, and we documented the number of shrubs and saplings inside the 5-m-radius plots. Data analysis Managed shrublands. We used nonparametric analysis-of-variance to examine whether Woodcock abundance differed between the 2 treatments (i.e., strip versus mosaic plots) or between treatment and control plots. We used Spearman’s correlation analysis to identify habitat variables that were highly correlated (i.e., r > 0.60), and then retained the correlated variable that we thought was most important based on management applicability (Bakermans et al. 2011, Roth et al. 2012). We found the following variables to be correlated: RBA and percent canopy cover (we retained RBA) and number of shrubs and percent shrub cover (we retained percent shrub cover). We included 4 vegetation variables in our analyses (percent herbaceous cover, percent shrub cover, number of saplings, and RBA). We used Pearson correlation to examine the relationships between Woodcock abundance and the mean values of vegetation characteristics. We also used a nonparametric, nested ANOVA design to test for differences in vegetation between control and treatment plots where site was considered as a random effect and treatment type as a fixed effect (Littell et al. 2002, Sokal and Rohlf 1995). Analyses were conducted with SAS (SAS 9.2, SAS Institute 2000). Timber management.We averaged the number of Woodcock and Golden-winged Warblers over all visits for each point count at each timber harvest. No annual differences in numbers of warblers were detected in stands that we surveyed in both years (n = 21, t20 = 1.65, P = 0.11); thus, we averaged abundance over the 2 years for each timber harvest. Due to low sample size, we excluded 2 groups from our analyses—sites where we encountered Golden-winged Warblers but not Woodcock (n = 1) and sites where neither species was detected (n = 1). We used a permutational multivariate analysis of variance (MANOVA; Anderson 2001) in the vegan package in R (Oksanen et al. 2014) to determine if vegetation variables differed Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 695 between the following 4 groups: (1) No GWWA - in timber harvests where we only surveyed for Golden-winged Warbler and did not detect the species (n = 25); (2) GWWA - in timber harvests where we only surveyed for Golden-winged Warbler and detected the species (n = 21); (3) BOTH - in timber harvests where we surveyed for both species and detected both species (n = 9); and (4) AMWO - in timber harvests where we surveyed for both species and detected only Woodcock (n = 6). We examined post hoc univariate tests to identify if individual vegetation metrics differed within each of the 4 groups. We used the same 4 vegetation metrics as used in the analyses for managed shrubland plots. In addition, we calculated descriptive statistics to summarize vegetation data in harvests for the 4 groups and created box-and-whisker plots to visually examine overlap and differences. Results Managed shrublands Woodcock were present in all 10 plots at BESP, and their density did not differ between the strip (mean = 4.8/10 ha, SE = 1.2, n = 3) and mosaic plots (mean = 5.1/10 ha, SE = 0.4, n = 4; F1,5 = 0.02, P = 0.91), and there was no difference between treatment (mean = 5.0/10 ha, SE = 0.5, n = 7) and control plots (mean = 3.3/10 ha, SE = 0.6, n = 3; F1,8 = 3.48, P = 0.10). The strongest correlation coefficient between vegetation metrics and Woodcock density occurred with number of saplings (r = -0.65, P = 0.04); the other 3 metrics were weakly correlated with density (r = -0.43–0.48, P = 0.16–0.40). There were significant differences between treatments and control plots for all vegetation variables (Fig. 1A–C). Percent herbaceous cover was least in control plots (i.e., 30% lower; F9,982 = 24.52, P < 0.01), but similar in strip and mosaic plots; conversely, percent shrub cover was greatest in control plots (i.e., 20% greater; F9,982 = 6.16, P < 0.01; Fig. 1A). Mosaic plots had the fewest saplings (F9,185 = 4.82, P < 0.01; Fig. 1B) but had greater RBA (F9,185 = 5.91, P < 0.01; Fig. 1C) than strip and control plots. RBA was 1.6 times greater in mosaic plots than strip plots. In addition, mosaic plots had an average of 40% fewer saplings compared to strip and control plots. Timber management We detected Woodcock in 88% of surveyed timber harvests (15 of 17), and abundance was 1.4 males (0.36 SE) per survey. We detected Golden-winged Warblers in 59% of timber harvests (10 of 17) that we also surveyed for Woodcock. Of the 17 stands surveyed for both species, we detected both species in 9 stands, only Woodcock in 6 stands, only Golden-winged Warblers in 1 stand, and neither species in 1 stand. We also detected Golden-winged Warblers at 46% of timber harvests (21 of 46) that were only surveyed for Golden-winged Warblers. Mean abundance of Goldenwinged Warblers was 0.6 males (0.10 SE) per survey across all stands (n = 62) and 1.5 males (0.14 SE) per survey in stands where they were detected (n = 31). We did not detect significant differences in vegetation between timber harvests grouped by detection category: no GWWA, single species (GWWA, AMWO), or both species (BOTH) (permutational MANOA F3,57 = 0.92, P = 0.48). Box-andNortheastern Naturalist 696 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 Figure 1. Comparison of mean (plus standard error bars) values for (A) percent herbaceous and shrub cover, (B) number of saplings/ha, and (C) residual basal area in strip plots, mosaic plots, and control plots at Bald Eagle State Park, PA, 2011. Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 697 whisker plots illustrate a great deal of overlap in the vegetation structure of timber harvests used by Woodcock and Warblers (Fig. 2A–D). Boxplots also illustrate that Woodcock used timber harvests with greater mean RBA than did Golden-winged Warblers (Fig. 2D). Timber harvests where we detected both Woodcock and Golden- winged Warblers had similar mean numbers of saplings. Mean shrub cover in timber harvests with Golden-winged Warbler was 37% and 33% for Woodcock. Discussion Our study results provide evidence that the implementation of management guidelines designed to increase regional populations of Golden-winged Warblers also benefits Woodcock. Densities of singing Woodcock in both types of managed-shrubland plots were remarkably similar regardless of the fact that the mosaic treatment was geared toward creating a finer-scale patchwork of vegetation layers that contained a mix of grasses, forbs, shrubs, saplings, and residual trees thought to favor Golden-winged Warblers. Retaining live, residual trees has proven to be effective for increasing Golden-winged Warbler density (Roth et al. 2014). Residual trees are generally limited in managed shrublands, but when present, they provide resources for foraging, song perches, and collecting nesting material (Confer et al. 2011, Kubel 2005). Surprisingly, previous Woodcock management practices prescribed the elimination of mature trees to allow for shrub and sapling regrowth and create foraging and nesting areas (Kelley et al. 2008, Wildlife Management Institute 2008, Williamson 2010). In contrast, our study and several others (Dessecker and McAuley 2001, Masse et al. 2014, Roboski and Causey 1981) have demonstrated that Woodcock use stands with a range of basal area up to 37 m2/ha. Woodcock often nest on drier sites where there is greater tree-canopy cover but that are not far from foraging areas where their young can feed (Wildlife Management Institute 2008, Williamson 2010). Results of previous studies of Woodcock habitat indicate that saplings are important because they provide shade to keep soil moist, offer protection, prevent overgrowth of herbaceous species, and may be used as foraging and diurnal habitat (Bourgeois 1977, Doherty et al. 2010, McAuley et al. 1996, Sepik et al. 1989, Steketee 2000, Straw et. al. 1986). However, our results in managed shrublands indicated that Woodcock density was negatively related to sapling numbers, and numbers of saplings in these plots were well below those recommended for foraging and diurnal cover (Williamson 2010). These findings suggest that Woodcock likely did not use these plots for foraging and diurnal activities, but instead used them for courtship, roosting, or nesting areas (Dessecker and McAuley 2001, Williamson 2010). In particular, mosaic plots that were managed according to Golden-winged Warbler prescriptions had the fewest saplings and likely provided better roosting and courtship habitat for Woodcock than strip and control plots. Timber harvests, however, had greater numbers of saplings than plots in the managed shrublands, and this feature could benefit both Golden-winged Warblers and Woodcock. Although Golden-winged Warblers avoid dense sapling areas for nesting (Bakermans et al. 2015, Bullock and Buehler 2008, Roth and Lutz 2004), their home range often includes areas characterized by dense sapling growth Northeastern Naturalist 698 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 Figure 2. Box-and-whisker plots of (A) % herbaceous cover, (B) % shrub cover, (C) number of saplings/ha, and (D) residual basal area (m2/ha) for timber harvests with no detections of Golden-winged Warblers (n = 25) and timber harvests with detections of Golden-winged Warblers (n = 21), American Woodcock only (n = 6), and both American Woodcock and Goldenwinged Warbler in the same stand (n = 9). For each group of data, boxplots provide: the sample minimum (where the line on the left ends), lower quantile (25% percentile that splits the lowest 25% of the data; the left side of the box), median (the middle value of all data; the line in the box), upper quantile (75 percentile; the right line on the box), sample maximum (where the line on the right ends), and the mean (average of all data; the diamond). Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 699 (Frantz et al., in press). Our data from timber harvests where we detected Woodcock and Golden-winged Warblers demonstrates extensive overlap of vegetation characteristics. Anecdotally, project staff commonly observed Woodcock nests, adults with broods, and lone adults while conducting Golden-winged Warbler point counts and nest searching in the BESP plots and the northeastern PA timber harvests (M.H. Bakermans and J.L. Larkin; pers. observ.). Indeed, several studies have documented Woodcock breeding and using managed shrublands and regenerating timber harvests for a variety of activities (Gregg and Hale 1977, McAuley et al. 1996). Dense shrub cover can provide protection from predators during foraging and incubating for both Woodcock and Golden-winged Warblers (Aldinger and Wood 2014, Confer et al. 2003, Kelley et al. 2008). In general, Golden-winged Warbler territories and nest sites, have ~20–50% shrub cover (Bullock and Buehler 2008, Frech and Confer 1987, Patton et al. 2010). At our sites, shrub cover in control plots in managed shrublands (Fig. 1A) was likely too high for nesting Goldenwinged Warblers because it shaded out Rubus spp. (blackberries and raspberries), lower-growing shrubs, and herbaceous cover. Open, herbaceous groundcover not only provides an important component of courtship, roosting, and nesting cover for Woodcock (Williamson 2010), but also provides nesting locations for Goldenwinged Warblers (Roth et al. 2012). Mosaic and strip plots had similarly high herbaceous cover (>45%), but timber harvests had noticeably less (mean of 17% for stands that had both Golden-winged Warblers and Woodcock). It should be noted that Aldinger et al. (2015) found that daily survival rate of nests declined for Golden-winged Warblers once grass cover exceeded 55%. We acknowledge that early-successional habitat surveyed in this study may not meet all habitat requirements for either species, and, in order to benefit woodcock and Golden-winged Warbler populations, these managed shrublands and timber harvests must also occur in landscapes that provide all nesting and post-fledging habitat requirements (i.e., in forested landscapes). Although this study lacked analytical power due to small sample sizes of plots, it provided evidence that Golden-winged Warbler habitat management benefits Woodcock. Reversing declines of Golden-winged Warblers and Woodcock in the Appalachians will require a well-planned and sustained effort to create and maintain sufficient amounts of young forest across forested landscapes (Buehler et al. 2007, Hunter et al. 2001, Roth et al. 2012). Management activity is especially important for Golden-winged Warblers, a species currently being considered for federal listing under the Endangered Species Act (Sewell 2010). We recommend that managers follow Golden-winged Warbler habitat guidelines in areas and community types where Golden-winged Warblers and Woodcock have the potential to co-occur because both species will likely benefit. These guidelines are presented in the Golden-winged Warbler status review and conservation plan (Roth et al. 2012). Based on our study, it is clear that different management systems will result in different vegetation structures, but both systems may provide some habitat requirements for both species. For example, regenerating stands from timber harvesting will result in a heterogeneous mix of herbaceous cover, shrubs, saplings, and residual trees. Within timber management systems that create young forest, we Northeastern Naturalist 700 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 recommend that mangers seek to create a vegetation structure that is 10–40% herbaceous cover, up to 7000 saplings/ha, and 5–10 m2/ha RBA of (mostly) hardwood canopy trees. As the RBA in a stand increases, trees should be clumped so as to retain open areas. In managed shrubland systems, we recommend that managers strive for 30–50% herbaceous cover, up to 1000 saplings/ha, and 3–4 m2/ha RBA. Note, however, that the shrubland-management sites in our study had few trees due to years of management that removed all trees, and the Golden-Winged Warbler conservation plan suggests retaining 2–8 m2/ha RBA in these management areas. In both management systems, however, shrub cover should be kept below 50%. Because management areas for Woodcock are large (200–400 ha; Williamson 2010), managers can create or maintain young forest habitat (15% of the management area) for Golden-winged Warblers within the appropriate landscape context (>70% forest cover within 2.5 km; Roth et al. 2012). Furthermore, Golden-winged Warblers are not likely to be found in group or single-tree selection harvests (Costello et al. 2000), so land managers should create stands at least 2–10 ha in size (Roth et al. 2012). We also encourage managers to use other potential methods to create or maintain young-forest habitats such as prescribed burning, prescribed grazing, and invasive plant management (see Roth et al. 2012). We strongly suggest a coordinated effort to monitor Woodcock and Golden-winged Warbler demographics on these lands to better quantify the mutual benefits to both speci es. Acknowledgments The Pennsylvania Department of Conservation and Natural Resources (Wild Resource Conservation Program), National Fish and Wildlife Foundation, US Fish and Wildlife Service, and Indiana University of Pennsylvania provided funding for this project. Fieldwork conducted by Wendy Leuenberger, Emily Bellush, Mack Frantz, Andrea Evans, Sean McGaughran, Brandon Miller, Douglas Schaefer, and Adam Sabatine was invaluable. We are grateful to John Ferrara (PA-DCNR-State Parks), Tim Ladner (PA-DCNR-Bureau of Forestry), and Mark Banker (Ruffed Grouse Society) for helping us find study sites and for their support and enthusiasm for this project. We offer a special thanks to Adam Smith (USFWS) and the Habitat Forever crew for their dedication to early-successional habitat. We are also grateful to Ms. Merleen Gunslack for providing us with housing and an occasional home-cooked meal during the field season. Literature Cited Aldinger, K.R., and P.B. Wood. 2014. Reproductive success and habitat characteristics of Golden-winged Warblers in high-elevation pasturelands. The Wilson Journal of Ornithology 126:279–287. Aldinger, K.R., T.M. Terhune II, P.B. Wood, D.A. Buehler, M.H. Bakermans, J.L. Confer, D.J. Flaspohler, J.L. Larkin, J.P. Loegering, K.L. Percy, A.M. Roth, and C.G. Smalling. 2015. Variables associated with nest survival of Golden-winged Warblers (Vermivora chrysoptera) among vegetation communities commonly used for nesting. Avian Conservation and Ecology 10(1):6. Available online at http://dx.doi.org/10.5751/ACE-00748-100106. Anderson, M.J. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecology 26:32–46. Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 701 Askins, R.A. 2001. Sustaining biological diversity in early-successional communities. Wildlife Society Bulletin 29:407–412. Bakermans, M.H., J.L. Larkin, B.W. Smith, T.M. Fearer, and B.C. Jones. 2011. Goldenwinged Warbler habitat best-management practices for forestlands in Maryland and Pennsylvania. American Bird Conservancy, The Plains, VA. 26 pp. Bakermans, M.H., B.W. Smith, B.C. Jones, and J.L. Larkin. 2015. Stand and within-stand factors influencing Golden-winged Warbler use of timber harvests in the central Appalachian Mountains. Avian Conservation and Ecology 10(1):10.Available online at http://dx.doi. org/10.5751/ACE-00747-100110. Bourgeois, A. 1977. Quantitative analysis of American Woodcock nest and brood habitat. Woodcock Symposium 6:109–183. Buehler, D.A., A.M. Roth, R. Vallender, T.C. Will, J.L. Confer, R.A. Canterbury, S.B. Swarthout, K.V. Rosenberg, and L.P. Bullock. 2007. Status and conservation priorities of Golden-winged Warbler (Vermivora chrysoptera) in North America. Auk 124:1439–1445. Bulluck, L.P., and D.A. Buehler. 2008. Factors influencing Golden-winged Warbler (Vermivora chrysoptera) nest-site selection and nest survival in the Cumberland Mountains of Tennessee. Auk 125:551–559. Confer, J.L., J.L. Larkin, and P.E. Allen. 2003. Effects of vegetation, interspecific competition, and brood parasitism on Golden-winged Warbler (Vermivora chrysoptera) nesting success. Auk 120:138–144. Confer, J.L., P. Hartman, and A. Roth. 2011. Golden-winged Warbler (Vermivora chrysoptera). Number 20, In A. Poole (Ed.). The Birds of North America. Academy of Natural Sciences, Philadelphia, PA, and American Ornithologists’ Union, Washington, DC. Cooper, T.R., and R.D. Rau. 2012. American Woodcock population status, 2012. US Fish and Wildlife Service, Laurel, MD. 16 pp. Costello, C.A., M. Yamasaki, P.J. Pekins, W.B. Leak, and C.D. Neefus. 2000. Songbird response to group selection harvests and clearcuts in a New Hampshire northern hardwood forest. Forest Ecology and Management 127:41–54. DeGraaf, R.M., and M. Yamasaki. 2003. Options for managing early-successional forest and shrubland-bird habitats in the northeastern United States. Forest Ecology and Management 185:179–191. Dessecker, D.R., and D.G. McAuley. 2001. Importance of early-successional habitat to Ruffed Grouse and American Woodcock. Wildlife Society Bulletin 29:156–165. Doherty, K.E., D.E. Anderson, J. Meunier, E. Oppelt, R.S. Lutz, and J.G. Bruggink. 2010. Foraging-location quality as a predictor of fidelity to a diurnal site for adult female American Woodcock, Scolopax minor. Wildlife Biology 16:379–388. Fenneman, N.M. 1938. Physiography of the Eastern United States, 1st Edition. McGraw Hill Book Company, Inc. New York, NY. 714 pp. Frantz, M.W., K.R. Aldinger, P.B. Wood, J. Duchamp, T. Nuttle, A.C. Vitz, and J.L. Larkin. In press. Space and habitat use of breeding Golden-winged Warblers in the central Appalachian Mountains. Studies in Avian Biology. Frech, M., and J.L. Confer. 1987. The Golden-winged Warbler: Competition with the Bluewinged Warbler and habitat selection in portions of southern, central, and northern New York. The Kingbird 37:65–71. Gill, F.B. 1980. Historical aspects of hybridization between Blue-winged and Goldenwinged Warblers. The Auk 97:1–18. Gregg, L.E., and J.B. Hale. 1977. Woodcock nesting habitat in northern Wisconsin. Auk 94:489–493. Gregory, R.D., D.W. Gibbons, and P.F. Donald. 2004. Bird census and survey techniques, Pp. 17–55, In W.J. Sutherland, I. Newton, and R.E. Green (Eds.). Bird Ecology and Conservation: A Handbook of Techniques. Oxford University Press, Oxford, UK. 408 pp. Northeastern Naturalist 702 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 Vol. 22, No. 4 Hunter, W.C., D.A. Buehler, R.A. Canterbury, J.L. Confer, and P.B. Hamel. 2001. Conservation of disturbance-dependent birds in eastern North America. Wildlife Society Bulletin 29:440–455. Kelley, J.R., S.J. Williamson, and T.R. Cooper (Eds). 2008. American Woodcock conservation plan: A summary of and recommendations for woodcock conservation in North America. Complied by the Woodcock Task Force, Migratory Shore and Upland Game Bird Working Group, Association of Fish and Wildlife Agencies. Wildlife Management Institute, Washington, DC. 162 pp. Klaus, N.A., and D.A. Buehler. 2001. Golden-winged Warbler breeding-habitat characteristics and nest success in clearcuts in the southern Appalachian Mountains. Wilson Bulletin 113:297–301. Kubel, J. 2005. Breeding ecology of Golden-winged Warblers in managed habitats of central Pennsylvania. M.Sc. Thesis. Pennsylvania State University, State College, PA. Larkin, J.L., and M.H. Bakermans. 2012. Golden-winged Warbler, Vermivora chyrsoptera. Pp. 350–351, In A.M. Wilson, D.W. Brauning, and R.S Mulvihill (Eds.). Second Atlas of Breeding Birds in Pennsylvania. Penn State University Press, State College, PA. 612 pp. Littell, R.C., W.W. Stroup, and R.J. Freund. 2002. SAS for Linear Models, Fourth Edition. SAS Institute Inc. Cary, NC. 496 pp. Lorimer, C.G., and A.S. White. 2003. Scale and frequency of natural disturbances in the northeastern US: Implications for early-successional forest habitats and regional age distributions. Forest Ecology and Management 185:41–64. Masse, R.J., M.C. Tefft, and S.R. McWilliams. 2014. Multiscale habitat selection by a forest-dwelling shorebird, the American Woodcock: Implications for forest management in southern New England, USA. Forest Ecology and Management 325:37–48. McAuley, D.G., J.R. Loncore, G.F. Sepik, and G.W. Pendleton. 1996. Habitat characteristics of American Woodcock nest sites on a managed area in Maine. Journal of Wildlife Management 60:138–148. McAuley, D.G., D.M. Keppie, and R.M. Whiting Jr. 2013. American Woodcock (Scolopax minor). No. 100, In A. Poole (Ed.). The Birds of North America Online. Cornell Lab of Ornithology, Ithaca, NY. Available online at http://bna.birds.cornell.edu/bna/species/ 100/articles/introduction. Accessed 24 July 2014. Oksanen, J., F. Guillaume Blanchet, R. Kindt, P. Legengdre, P.R. Minchin, R.B. O’Hara, G.L. Simpson, P. Solymos, M.H.H. Stevens, and H. Wagner. 2014. Vegan: Community ecology package. R package version 2.2-0. Patton, L.L., D.S. Maehr, J.E. Duchamp, S. Fei, J.W. Gassett, and J.L. Larkin. 2010. Do the Golden-winged Warbler and Blue-winged Warbler exhibit species-specific differences in their breeding-habitat use? Avian Conservation and Ecology 5(2):2. Roboski, J.C., and M.K. Causey. 1981. Incidence, habitat use, and chronology of woodcock nesting in Alabama. Journal of Wildlife Management 45:793–797. Rossell, C.R., S.C. Patch, and S.P. Wilds. 2003. Attributes of Golden-winged Warbler territories in a mountain wetland. Wildlife Society Bulletin 31:1099–1104. Roth, A.M., and S. Lutz. 2004. Relationship between territorial male Golden-winged Warblers in managed aspen stands in northern Wisconsin, USA. Forest Science 50:153–161. Roth, A.M., R.W. Rohrbaugh, K. Aldinger, M.H. Bakermans, S. Barker Swarthout, D.A. Buehler, J.L. Confer, D. Crawford, C. Fris, R.M. Fowlds, J.L. Larkin, J. Loegering, J.D. Lowe, M. Piorkowski, K.V. Rosenberg, C. Smalling, T.M. Terhune, R. Vallender, T. Will, and P.B. Wood. 2012. Golden-winged Warbler breeding season conservation plan. Pp. 3-1–3-88, In A.M. Roth, R.W. Rohrbaugh, T. Will, and D.A. Buehler (Eds.). Goldenwinged Warbler Status Review and Conservation Plan. Available online at http://www. gwwa.org/plan.html. Accessed 22 April 2015. Northeastern Naturalist Vol. 22, No. 4 M.H. Bakermans, C.L. Ziegler, and J.L. Larkin 2015 703 Roth, A.M., D.J. Flaspohler, and C.R. Webster. 2014. Legacy-tree retention in young aspen forest improves nesting-habitat quality for Golden-winged Warbler (Vermivora chrysoptera). Forest Ecology and Management 321:61–70. SAS Institute, Inc. 2000. SAS Language Version 9.2. SAS Institute, Inc., Cary, NC. Sauer, J.R., J.E. Hines, J.E. Fallon, K.L. Pardieck, D.J. Ziolkowski, Jr., and W.A. Link. 2014. The North American Breeding Bird Survey, Results and Analysis 1966–2012. Version 02.19.2012 USGS Patuxent Wildlife Research Center, Laurel, MD. Available online at http://www.mbr-pwrc.usgs.gov/bbs/. Accessed 20 July 2014. Sepik, G.F., D.G. McAuley, J.R. Longcore, and E.L. Derleth. 1989. Habitat requirements and management of woodcock in the Northeast: Assessment of knowledge and needs. Pp. 97–109, In J.C. Finley and M.C. Brittingham (Eds.). Timber Management and Its Effects on Wildlife. Proceedings of the 1989 Pennsylvania State Forest Resources Issues Conference. Pennsylvania State University, University Park, PA. Sevon, W.D. 2000. Physiographic provinces of Pennsylvania, 4th Edition. Scale 1:2,000,000, 8.5” x 11”. Pennsylvania Geological Survey. Harrisburg, PA. Sewell, A. 2010. Petition to list the Golden-winged Warbler (Vermivora chrysoptera) as a threatened or endangered species under the US Endangered Species Act. Available online at http://gwwa.org/resources/Petition%20to%20List%20GWWA_comp.pdf. Accessed November 2015. Sokal, R.R., and F.J. Rohlf. 1995. Biometry: The Principles and Practice of Statistics in Biological Research. 3rd Edition. W.H. Freeman, New York, NY. 887 pp. Steketee, A.K. 2000. Predicting habitat suitability for American Woodcock and landscapelevel assessment of habitat in West Virginia. Ph.D. Dissertation. West Virginia University, Morgantown, WV. 123 pp. Stoleson, S.H., and J.L. Larkin. 2010. Breeding birds of Pennsylvania: Forest communities. Pp. 14–27, In S.K. Majumdar, T.L. Master, M.C. Brittingham, R.M. Ross, R.S. Mulvihill, and J.E. Huffman (Eds.). Avian Ecology and Conservation: A Pennsylvania Focus with National Implications. The Pennsylvania Academy of Science, Easton, PA. 368 pgs. Straw, J.A., Jr., J.S. Wakeley, and J.E. Hudgins. 1986. A model for management of diurnal habitat for American Woodcock in Pennsylvania. Journal of Wildlife Management 50:378–383. US Department of Agriculture (USDA). 2012. Working Lands for Wildlife. Natural Resources Conservation Service, Washington, DC. Available online at http://www.nrcs. usda.gov/Internet/FSE_DOCUMENTS/stelprdb1047545.pdf. Accessed 15 May 2015. US Fish and Wildlife Service (USFWS). 2011. American Woodcock singing-ground survey: Background and instructions. Migratory Bird Program, Washington, DC. Available online at https://migbirdapps.fws.gov/woodcock/training_tool_documents/US_survey_ background_instructions.pdf. Accessed 15 February 2015. Vallender, R., Friesen, V.L., and R.J. Robertson. 2007. Paternity and performance of Golden-winged Warblers (Vermivora chrysoptera) and Golden-winged x Blue-winged Warbler (V. pinus) hybrids at the leading edge of a hybrid zone. Behavioral Ecology and Sociobiology 12:1797–1807. Wildlife Management Institute. 2008. American Woodcock Habitat: Best management practices for the Central Appalachian Mountains Region. Wildlife Management Institute, Washington, DC. 28 pp. Williamson, S.J. 2010. American Woodcock: Habitat best-management practices for the Northeast. Wildlife Insight 89. US Department of Agriculture, Natural Resources Conservation Service. Washington, DC. 26 pp.