Wildlife resistance and protection in a changing New England landscape.

Rapid changes in climate and land use threaten the persistence of wildlife species. Understanding where species are likely to occur now and in the future can help identify areas that are resistant to change over time and guide conservation planning. We estimated changes in species distribution patterns and spatial resistance in five future scenarios for the New England region of the northeastern United States. We present scenario-specific distribution change maps for nine harvested wildlife species, identifying regions of increasing, decreasing, or stable habitat suitability within each scenario. Next, we isolated areas where species occurrence probability is high (p > 0.7) and resistant to change across all future scenarios. Resistance was also evaluated relative to current land protection to identify patterns in and out of Protected Areas (PAs). Generally, species distributions declined in area over the 50-year assessment period (2010-2060), with the greatest average declines occurring for moose (-40.9%) and wild turkey (-22.1%). Species resistance varied considerably across the region, with coyote demonstrating the highest average regional resistance (91.81% of the region) and moose demonstrating the lowest (0.76% of the region). At the state level, average focal species resistance was highest in Maine (the largest state) and lowest in Massachusetts. Many of the focal species showed high overlap in resistance and land protection. Coyote, white-tailed deer, and black bear had the highest probability of resistance, given protection, while moose and wild turkey had the highest probability of protection, given resistance. Overall, relatively small portions of New England-ranging between 0.25% and 21.12%-were both protected and resistant for the focal species. Our results provide estimates of resistance that can inform conservation planning for commonly harvested species that are important ecologically, economically, and culturally to the region. Expanding protected area coverage to include resistant areas may provide longer term benefits to these species.

Public acceptability of development in the Northern Forest of Vermont, USA-The influence of wildlife information, recreation involvement, and demographic characteristics.

Increasing development such as roads and houses will alter future landscapes and result in biological, social, and economic trade-offs. Managing development requires information on the public's acceptability of development and understanding which factors shape acceptability. In this study, we examined three questions: 1) What is the public's acceptability of development? 2) Is acceptability of development influenced by wildlife information? and 3) Is the maximum amount of acceptable development influenced by views about wildlife, involvement in outdoor recreation, and demographic factors? We conducted a visual-preference survey of 9,000 households in Vermont, USA that asked about acceptable levels of development, acceptability of wildlife, involvement in recreation, and individual and town demographics. The survey response rate was 44%. Maximum acceptable condition (MAC) for development was 41 houses/km2 and not meaningfully influenced by broader consequences of development on seven common wildlife species. MAC was influenced by views on individual species, including bear and coyote, but not by other species such as deer, fox, and bobcat. Respondents with a positive attitude toward bear favored less development, whereas the opposite relationship existed for coyote. Similarly, MAC was negatively influenced by involvement in birding and hunting, but not by other common recreational activities. Among demographic factors, respondents that were younger and not born in Vermont were more accepting of development. Population density also positively influenced development acceptability. Results provide measures of the public's acceptability of development that can help guide decision-making about development, wildlife, and recreation management.

AMModels: An R package for storing models, data, and metadata to facilitate adaptive management.

Agencies are increasingly called upon to implement their natural resource management programs within an adaptive management (AM) framework. This article provides the background and motivation for the R package, AMModels. AMModels was developed under R version 3.2.2. The overall goal of AMModels is simple: To codify knowledge in the form of models and to store it, along with models generated from numerous analyses and datasets that may come our way, so that it can be used or recalled in the future. AMModels facilitates this process by storing all models and datasets in a single object that can be saved to an .RData file and routinely augmented to track changes in knowledge through time. Through this process, AMModels allows the capture, development, sharing, and use of knowledge that may help organizations achieve their mission. While AMModels was designed to facilitate adaptive management, its utility is far more general. Many R packages exist for creating and summarizing models, but to our knowledge, AMModels is the only package dedicated not to the mechanics of analysis but to organizing analysis inputs, analysis outputs, and preserving descriptive metadata. We anticipate that this package will assist users hoping to preserve the key elements of an analysis so they may be more confidently revisited at a later date.

Carbon storage, timber production, and biodiversity: comparing ecosystem services with multi-criteria decision analysis.

Increasingly, land managers seek ways to manage forests for multiple ecosystem services and functions, yet considerable challenges exist in comparing disparate services and balancing trade-offs among them. We applied multi-criteria decision analysis (MCDA) and forest simulation models to simultaneously consider three objectives: (1) storing carbon, (2) producing timber and wood products, and (3) sustaining biodiversity. We used the Forest Vegetation Simulator (FVS) applied to 42 northern hardwood sites to simulate forest development over 100 years and to estimate carbon storage and timber production. We estimated biodiversity implications with occupancy models for 51 terrestrial bird species that were linked to FVS outputs. We simulated four alternative management prescriptions that spanned a range of harvesting intensities and forest structure retention. We found that silvicultural approaches emphasizing less frequent harvesting and greater structural retention could be expected to achieve the greatest net carbon storage but also produce less timber. More intensive prescriptions would enhance biodiversity because positive responses of early successional species exceeded negative responses of late successional species within the heavily forested study area. The combinations of weights assigned to objectives had a large influence on which prescriptions were scored as optimal. Overall, we found that a diversity of silvicultural approaches is likely to be preferable to any single approach, emphasizing the need for landscape-scale management to provide a full range of ecosystem goods and services. Our analytical framework that combined MCDA with forest simulation modeling was a powerful tool in understanding trade-offs among management objectives and how they can be simultaneously accommodated.

Estimating landscape carrying capacity through maximum clique analysis.

Habitat suitability (HS) maps are widely used tools in wildlife science and establish a link between wildlife populations and landscape pattern. Although HS maps spatially depict the distribution of optimal resources for a species, they do not reveal the population size a landscape is capable of supporting--information that is often crucial for decision makers and managers. We used a new approach, "maximum clique analysis," to demonstrate how HS maps for territorial species can be used to estimate the carrying capacity, N(k), of a given landscape. We estimated the N(k) of Ovenbirds (Seiurus aurocapillus) and bobcats (Lynx rufus) in an 1153-km2 study area in Vermont, USA. These two species were selected to highlight different approaches in building an HS map as well as computational challenges that can arise in a maximum clique analysis. We derived 30-m2 HS maps for each species via occupancy modeling (Ovenbird) and by resource utilization modeling (bobcats). For each species, we then identified all pixel locations on the map (points) that had sufficient resources in the surrounding area to maintain a home range (termed a "pseudo-home range"). These locations were converted to a mathematical graph, where any two points were linked if two pseudo-home ranges could exist on the landscape without violating territory boundaries. We used the program Cliquer to find the maximum clique of each graph. The resulting estimates of N(k) = 236 Ovenbirds and N(k) = 42 female bobcats were sensitive to different assumptions and model inputs. Estimates of N(k) via alternative, ad hoc methods were 1.4 to > 30 times greater than the maximum clique estimate, suggesting that the alternative results may be upwardly biased. The maximum clique analysis was computationally intensive but could handle problems with < 1500 total pseudo-home ranges (points). Given present computational constraints, it is best suited for species that occur in clustered distributions (where the problem can be broken into several, smaller problems), or for species with large home ranges relative to grid scale where resampling the points to a coarser resolution can reduce the problem to manageable proportions.

A multispecies framework for landscape conservation planning.

Rapidly changing landscapes have spurred the need for quantitative methods for conservation assessment and planning that encompass large spatial extents. We devised and tested a multispecies framework for conservation planning to complement single-species assessments and ecosystem-level approaches. Our framework consisted of 4 elements: sampling to effectively estimate population parameters, measuring how human activity affects landscapes at multiple scales, analyzing the relation between landscape characteristics and individual species occurrences, and evaluating and comparing the responses of multiple species to landscape modification. We applied the approach to a community of terrestrial birds across 25,000 km(2) with a range of intensities of human development. Human modification of land cover, road density, and other elements of the landscape, measured at multiple spatial extents, had large effects on occupancy of the 67 species studied. Forest composition within 1 km of points had a strong effect on occupancy of many species and a range of negative, intermediate, and positive associations. Road density within 1 km of points, percent evergreen forest within 300 m, and distance from patch edge were also strongly associated with occupancy for many species. We used the occupancy results to group species into 11 guilds that shared patterns of association with landscape characteristics. Our multispecies approach to conservation planning allowed us to quantify the trade-offs of different scenarios of land-cover change in terms of species occupancy.

Characteristics of important stopover locations for migrating birds: remote sensing with radar in the Great Lakes basin.

A preliminary stage in developing comprehensive conservation plans involves identifying areas used by the organisms of interest. The areas used by migratory land birds during temporal breaks in migration (stopover periods) have received relatively little research and conservation attention. Methodologies for identifying stopover sites across large geographic areas have been, until recently, unavailable. Advances in weather-radar technology now allow for evaluation of bird migration patterns at large spatial scales. We analyzed radar data (WSR-88D) recorded during spring migration in 2000 and 2001 at 6 sites in the Great Lakes basin (U.S.A.). Our goal was to link areas of high migrant activity with the land-cover types and landscape contexts corresponding to those areas. To characterize the landscapes surrounding stopover locations, we integrated radar and land-cover data within a geographic information system. We compared landscape metrics within 5 km of areas that consistently hosted large numbers of migrants with landscapes surrounding randomly selected areas that were used by relatively few birds during migration. Concentration areas were characterized by 1.2 times more forest cover and 9.3 times more water cover than areas with little migrant activity. We detected a strong negative relationship between activity of migratory birds and agricultural land uses. Examination of individual migration events confirmed the importance of fragments of forested habitat in highly altered landscapes and highlighted large concentrations of birds departing from near-shore terrestrial areas in the Great Lakes basin. We conclude that conservation efforts can be more effectively targeted through intensive analysis of radar imagery.

Grassland songbird survival and recruitment in agricultural landscapes: implications for source-sink demography.

Population growth and decline are particularly sensitive to changes in three key life-history parameters: annual productivity, juvenile survival, and adult survival. However, for many species these parameters remain unknown. For example, although grassland songbirds are imperiled throughout North America, for this guild, only a small number of studies have assessed these parameters. From 2002 to 2006, in the agricultural landscape of the Champlain Valley of Vermont and New York, USA, we studied Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus) demography on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. We assessed whether these treatments affected adult apparent survival (phi) and recruitment (f), how sensitive these parameters were to the presence of nonbreeders and local dispersal, and the populations' ability to persist in these four habitats. On average, birds using late-hayed fields had > 25% higher apparent survival than those on the more intensively managed early-hayed, middle-hayed, and grazed fields. Overall male phi was 35% higher than female phi, and Savannah Sparrow phi was 44% higher than Bobolink phi. Across all analyses and treatments, apparent survival estimates were 0.58-0.85 for male and 0.48-0.71 for female Savannah Sparrows, and 0.52-0.70 for male and 0.19-0.55 for female Bobolinks. For males of both species, potential nonbreeders decreased the precision of and lowered apparent survival estimates by 25%; female estimates showed little variation with the inclusion of nonbreeders. Inclusion of local dispersal observations increased apparent survival estimates and, in many cases, increased precision, though the effect was stronger for Savannah Sparrows than for Bobolinks, and also stronger for males than for females. High Savannah Sparrow apparent survival rates resulted in stable or near stable populations (lambda approximately 1), particularly in late-hayed and grazed fields, while low Bobolink apparent survival rates resulted in strongly declining populations (lambda < 1) in all treatments.

Agricultural management affects evolutionary processes in a migratory songbird.

Hay harvests have detrimental ecological effects on breeding songbirds, as harvesting results in nest failure. Importantly, whether harvesting also affects evolutionary processes is not known. We explored how hay harvest affected social and genetic mating patterns, and thus, the overall opportunity for sexual selection and evolutionary processes for a ground-nesting songbird, the Savannah sparrow (Passerculus sandwichensis). On an unharvested field, 55% of females were in polygynous associations, and social polygyny was associated with greater rates of extra-pair paternity (EPP). In this treatment, synchrony explained variation in EPP rates, as broods by more synchronous females had more EPP than broods by asynchronous females. In contrast, on a harvested field, simultaneous nest failure caused by haying dramatically decreased the overall incidence of EPP by increasing the occurrence of social monogamy and, apparently, the ability of polygynous males to maintain paternity in their own nests. Despite increased social and genetic monogamy, these haying-mediated changes in mating systems resulted in greater than twofold increase in the opportunity for sexual selection. This effect arose, in part, from a 30% increase in the variance associated with within-pair fertilization success, relative to the unharvested field. This effect was caused by a notable increase (+110%) in variance associated with the quality of social mates following simultaneous nest failure. Because up to 40% of regional habitat is harvested by early June, these data may demonstrate a strong population-level effect on mating systems, sexual selection, and consequently, evolutionary processes.

Grassland songbirds in a dynamic management landscape: behavioral responses and management strategies.

In recent decades, earlier and more frequent harvests of agricultural grasslands have been implicated as a major cause of population declines in grassland songbirds. From 2002 to 2005, in the Champlain Valley of Vermont and New York, USA, we studied the reproductive success of Savannah Sparrows (Passerculus sandwichensis) and Bobolinks (Dolichonyx oryzivorus) on four grassland treatments: (1) early-hayed fields cut before 11 June and again in early- to mid-July; (2) middle-hayed fields cut once between 21 June and 10 July; (3) late-hayed fields cut after 1 August; and (4) rotationally grazed pastures. Both the number of fledglings per female per year and nest success (logistic-exposure method) varied among treatments and between species. Although birds initiated nests earlier on early-hayed fields compared to others, haying caused 99% of active Savannah Sparrow and 100% of active Bobolink nests to fail. Both the initial cutting date and time between cuttings influenced renesting behavior. After haying, Savannah Sparrows generally remained on early-hayed fields and immediately renested (clutch completion 15.6 +/- 1.28 days post-haying; all values are reported as mean +/- SE), while Bobolinks abandoned the fields for at least two weeks (mean clutch completion 33 +/- 0.82 days post-haying). While female Savannah Sparrows fledged more offspring per year (1.28 +/- 0.16) than female Bobolinks (0.05 +/- 0.05), reproductive success on early-hayed fields was low. The number of fledglings per female per year was greater on middle-hayed fields (Savannah Sparrows, 3.47 +/- 0.42; Bobolinks, 2.22 +/- 0.26), and late-hayed fields (Savannah Sparrows, 3.29 +/- 0.30; Bobolinks, 2.79 +/- 0.18). Reproductive success was moderate on rotationally grazed pastures, where female Savannah Sparrows and female Bobolinks produced 2.32 +/- 0.25 and 1.79 +/- 0.33 fledgling per year, respectively. We simultaneously conducted cutting surveys throughout the Champlain Valley and found that 3-8% of hayfield habitat was cut by 1-4 June, 25-40% by 12-16 June, and 32-60% by 28 June-2 July. Thus, the majority of grassland habitat was cut during the breeding season; however, late-hayed fields served as high-quality reserves for late-nesting female Bobolinks that were displaced from previously hayed fields. For fields first cut in May, a 65-day interval between cuts could provide enough time for both species to successfully fledge young.