Jeffrey Hepinstall-Cymerman

Cougar space use and movements in the wildland–urban landscape of western Washington

The wildland–urban interface lies at the confluence of human-dominated and wild landscapes, creating a number of management and conservation challenges. Because wildlife ecology, behavior, and evolution at this interface are shaped by both natural and human phenomena, this requires greater understanding of how diverse factors affect ecosystem and population processes. We illustrate the challenge of understanding and managing a frequent and often undesired inhabitant of the wildland–urban landscape, the cougar (Puma concolor). In wildland and residential areas of western Washington State, USA, we captured and radiotracked 27 cougars to model space use and understand the role of landscape features in interactions (sightings, encounters, and depredations) between cougars and humans. Resource utilization functions (RUFs) identified cougar use of areas with features that were probably attractive to prey, influential on prey vulnerability, and associated with limited or no residential development. Early-successional forest (+), conifer forest (+), distance to road (−), residential density (−), and elevation (−) were significant positive and negative predictors of use for the population, whereas use of other landscape features was highly variable. Space use and movement rates in wildland and residential areas were similar because cougars used wildland-like forest patches, reserves, and corridors in residential portions of their home range. The population RUF was a good predictor of confirmed cougar interactions, with 72% of confirmed reports occurring in the 50% of the landscape predicted to be medium-high and high cougar use areas. We believe that there is a threshold residential density at which the level of development modifies the habitat but maintains enough wildland characteristics to encourage moderate levels of cougar use and maximize the probability of interaction. Wildlife managers trying to reduce interactions between cougars and people should incorporate information on spatial ecology and landscape characteristics to identify areas with the highest overlap of human and cougar use to focus management, education, and landscape planning. Resource utilization functions provide a proactive tool to guide these activities for improved coexistence with wildlife using both wildland and residential portions of the landscape.

Mapping Geographically Isolated Wetlands in the Dougherty Plain, Georgia, USA

Increasing interest in isolated wetlands requires an understanding of the location, spatial extent, and configuration of the resource. The National Wetlands Inventory (NWI) is the most commonly used data source for this information; however, the accuracy is limited in some contexts, e.g., agricultural, seasonally-ponded, or forested wetlands. This study sought to improve isolated wetland mapping accuracy by integrating currently available NWI maps with other geospatial data sources (i.e., Soil Survey Geographic Database [SSURGO], Digital Raster Graphics [DRGs], and Digital Elevation Models [DEMs]). Relative to NWI, the optimal model (combining data derived from NWI, SSURGO, and DRGs) identified 1,874 additional isolated wetlands and 19,737-ha of additional isolated wetland area. A remote accuracy assessment indicated a high degree of accuracy for the optimal model (Kappa = 0.88, Sensitivity = 90%, and Specificity = 98%), as compared to NWI maps (Kappa = 0.70, Sensitivity = 68%, and Specificity = 99%). Small wetlands (< 4-ha) dominated the wetland population and reduced nearest neighbor distances between wetlands. Isolated wetlands were clustered and clustering was strongest among larger wetlands. This study identified a framework for improving the accuracy of wetland maps and serves as a foundation for ongoing wetland studies within the Dougherty Plain.

Urban growth patterns and growth management boundaries in the Central Puget Sound, Washington, 1986-2007

Many regions of the globe are experiencing rapid urban growth, the location and intensity of which can have negative effects on ecological and social systems. In some locales, planners and policy makers have used urban growth boundaries to direct the location and intensity of development; however the empirical evidence for the efficacy of such policies is mixed. Monitoring the location of urban growth is an essential first step in understanding how the system has changed over time. In addition, if regulations purporting to direct urban growth to specific locales are present, it is important to evaluate if the desired pattern (or change in pattern) has been observed. In this paper, we document land cover and change across six dates (1986, 1991, 1995, 1999, 2002, and 2007) for six counties in the Central Puget Sound, Washington State, USA. We explore patterns of change by three different spatial partitions (the region, each county, 2000 U.S. Census Tracks), and with respect to urban growth boundaries implemented in the late 1990’s as part of the state’s Growth Management Act. Urban land cover increased from 8 to 19% of the study area between 1986 and 2007, while lowland deciduous and mixed forests decreased from 21 to 13% and grass and agriculture decreased from 11 to 8%. Land in urban classes outside of the urban growth boundaries increased more rapidly (by area and percentage of new urban land cover) than land within the urban growth boundaries, suggesting that the intended effect of the Growth Management Act to direct growth to within the urban growth boundaries may not have been accomplished by 2007. Urban sprawl, as estimated by the area of land per capita, increased overall within the region, with the more rural counties within commuting distance to cities having the highest rate of increase observed. Land cover data is increasingly available and can be used to rapidly evaluate urban development patterns over large areas. Such data are important inputs for policy makers, urban planners, and modelers alike to manage and plan for future population, land use, and land cover changes.

DIFFERENCES IN SPACE USE by COMMON RAVENS IN RElATION TO SEx, bREEDING STATUS, AND KINShIP

Abstract. Group differences in avian space use relate to group differences in resource use and demographic parameters. However, studies that consider year-round, intraspecific variation in the space use of noncooperatively breeding species are relatively rare. A greater understanding of factors relating to intraspecific variation in space use is especially important for managing human-subsidized predators, such as the Common Raven (Corvus corax). We hypothesized that sex, sociality, and the distribution of bonanzas of food should influence year-round space use by breeding and nonbreeding Common Ravens on the Olympic Peninsula of Washington State. We detected differences in space use between breeders and nonbreeders but not between the sexes. Breeders shared little space with their neighbors and displayed strong site fidelity, except in the fall and winter or after the death of a mate, when some breeding ravens moved extensively. Nonbreeders moved widely, were more gregarious, and their home ranges intersected a greater proportion of communal food resources than did those of breeders. Breeders shared little space with their adult neighbors, but they shared more space with nonbreeders when communal food resources fell within their territories. Pair bonds were broken only by the death of a partner, which in some cases was followed by extensive movements by the surviving adult prior to pairing with a new mate or settling in a new breeding territory. This study is the first to consider the space use of both nonbreeding and breeding Common Ravens in the same population simultaneously.

Using urban landscape trajectories to develop a multi-temporal land cover database to support ecological modeling.

Urbanization and the resulting changes in land cover have myriad impacts on ecological systems. Monitoring these changes across large spatial extents and long time spans requires synoptic remotely sensed data with an appropriate temporal sequence. We developed a multi-temporal land cover dataset for a six-county area surrounding the Seattle, Washington State, USA, metropolitan region. Land cover maps for 1986, 1991, 1995, 1999, and 2002 were developed from Landsat TM images through a combination of spectral unmixing, image segmentation, multi-season imagery, and supervised classification approaches to differentiate an initial nine land cover classes. We then used ancillary GIS layers and temporal information to define trajectories of land cover change through multiple updating and backdating rules and refined our land cover classification for each date into 14 classes. We compared the accuracy of the initial approach with the landscape trajectory modifications and determined that the use of landscape trajectory rules increased our ability to differentiate several classes including bare soil (separated into cleared for development, agriculture, and clearcut forest) and three intensities of urban. Using the temporal dataset, we found that between 1986 and 2002, urban land cover increased from 8 to 18% of our study area, while lowland deciduous and mixed forests decreased from 21 to 14%, and grass and agriculture decreased from 11 to 8%. The intensity of urban land cover increased with 252 km2 in Heavy Urban in 1986 increasing to 629 km2 by 2002. The ecological systems that are present in this region were likely significantly altered by these changes in land cover. Our results suggest that multi-temporal (i.e., multiple years and multiple seasons within years) Landsat data are an economical means to quantify land cover and land cover change across large and highly heterogeneous urbanizing landscapes. Our data, and similar temporal land cover change products, have been used in ecological modeling of past, present, and likely future changes in ecological systems (e.g., avian biodiversity, water quality). Such data are important inputs for ecological modelers, policy makers, and urban planners to manage and plan for future landscape change.

Associations between multiscale landscape characteristics and breeding bird abundance and diversity across urban-rural gradients in Northeastern Georgia, USA

Urbanization is rapidly changing the southeastern US landscape, particularly in Georgia within and around the Atlanta metropolitan area, the fastest-growing Southeastern population center. Landscape characteristics related to human disturbance, landscape composition, and landscape configuration vary across the urban-rural gradient and are easily and inexpensively evaluated using geographic information systems (GIS). Previous studies have suggested that avian communities and populations respond in scale-dependent ways to urbanization-related landscape changes through changes in abundance and diversity. We conducted a 2-year study (2007–2008) of the response of breeding bird population abundance, community abundance, species richness, and relative diversity in young and mature single-family residential areas to 15 landscape characteristics measured at multiple spatial scales across urban-rural development intensity gradients near Athens, Georgia. We grouped birds by species, entire site assemblage, and by functional guild affiliation. Our models suggest strong relationships between the landscape and both community and population abundance of birds, as well as a somewhat weaker relationship with species richness. We detected only a weak relationship between breeding season relative diversity and landscape characteristics; we hypothesize a possible seasonal component to that relationship based on an earlier study. Our results suggest that widely available geospatial metrics of human disturbance and landscape pattern can be used to model breeding bird abundance and diversity across urban-rural gradients. This study sets the framework for a landscape scale understanding of the effects of housing developments and development intensity on breeding birds in northeastern Georgia and such a landscape-based approach to modeling species numbers represents a valuable tool in natural resources management.

Occupancy models for data with false positive and false negative errors and heterogeneity across sites and surveys

Summary 1. False positive detections, such as species misidentifications, occur in ecological data, although many models do not account for them. Consequently, these models are expected to generate biased inference. 2. The main challenge in an analysis of data with false positives is to distinguish false positive and false negative processes while modelling realistic levels of heterogeneity in occupancy and detection probabilities without restrictive assumptions about parameter spaces. 3. Building on previous attempts to account for false positive and false negative detections in occupancy models, we present hierarchical Bayesian models that utilize a subset of data with either confirmed detections of a species’ presence (CP model) or both confirmed presences and confirmed absences (CACP model). We demonstrate that our models overcome the challenges associated with false positive data by evaluating model performance in Monte Carlo simulations of a variety of scenarios. Our models also have the ability to improve inference by incorporating previous knowledge through informative priors. 4. We describe an example application of the CP model to quantify the relationship between songbird occupancy and residential development, plus we provide instructions for ecologists to use the CACP and CP models in their own research. 5. Monte Carlo simulation results indicated that, when data contained false positive detections, the CACP and CP models generated more accurate and precise posterior probability distributions than a model that assumed data did not have false positive errors. For the scenario sw e expect to be most generally applicable, those with heterogeneity in occupancy and detection, the CACP and CP models generated essentially unbiased posterior occupancy probabilities. The CACP model with vague priors generated unbiased posterior distributions for covariate coefficients. The CP model generated unbiased posterior distributions for covariate coefficients with vague or informative priors, depending on the function relating covariates to occupancy probabilities. We conclude that the CACP and CP models generate accurate inference in situations with false positive data for which previous models were not suitable.

From wetland specialist to hand-fed generalist: shifts in diet and condition with provisioning for a recently urbanized wading bird

Many wildlife species shift their diets to use novel resources in urban areas. The consequences of these shifts are not well known, and consumption of reliable—but low quality—anthropogenic food may present important trade-offs for wildlife health. This may be especially true for carnivorous species such as the American white ibis (Eudocimus albus), a nomadic wading bird which has been increasingly observed in urban parks in South Florida, USA. We tested the effects of anthropogenic provisioning on consumer nutrition (i.e. dietary protein), body condition and ectoparasite burdens along an urban gradient using stable isotope analysis, scaled mass index values and GPS transmitter data. Ibises that assimilated more provisioned food were captured at more urban sites, used more urban habitat, had lower mass–length residuals, lower ectoparasite scores, assimilated less δ15N and had smaller dietary isotopic ellipses. Our results suggest that ibises in urban areas are heavily provisioned with anthropogenic food, which appears to offer a trade-off by providing low-quality, but easily accessible, calories that may not support high mass but may increase time available for anti-parasite behaviours such as preening. Understanding such trade-offs is important for investigating the effects of provisioning on infection risk and the conservation of wildlife in human-modified habitats. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.

Six Decades (1948-2007) of Landscape Change in the Dougherty Plain of Southwest Georgia, USA

We used aerial photographs from 1948, 1968, 1993, and 2007 to construct a chronosequence of land use and land cover (LULC) representing 10 percent of the Dougherty Plain physiographic district in southwestern Georgia. We found large declines in the area of forest and unirrigated agriculture and increases in planted pine and irrigated agriculture. The landscape became more fragmented (i.e., more and smaller patches) and dominated by some classes. Trends varied among LULC classes with forest patches becoming smaller and irrigated agriculture becoming more prevalent, especially in the central portion of the Dougherty Plain where limited surface waters required use of groundwater wells for irrigation. Planted pine was converted primarily from marginal agricultural lands between 1948 and 1968, but increasingly from forest in later time periods. LULC patterns varied spatially within the Dougherty Plain indicating that LULC may be driven by finer scale phenomena. Drivers of observed changes included the widespread adoption of center-pivot irrigation and land conservation programs.

The Northern Appalachian/Acadian Ecoregion, North America

The Northern Appalachian/Acadian ecoregion in northeastern United States and southeastern Canada is projected to experience dramatically increased temperatures by the end of the twenty-first century, potentially driving numerous changes in species distributions throughout the region. For species to respond to such changes, landscape-scale conservation planning must result in increased levels of connectivity both within the ecoregion and with neighboring areas. Numerous initiatives have sought to promote ecological health and connectivity throughout all or a part of this ecoregion, particularly Two Countries, One Forest, a binational umbrella organization. Work in the region suggests the need for increased attention to be given to planning for linkages across landscape scales to allow for both short- and long-term movement of species, and for coupling connectivity with efforts to enhance ecosystem resilience throughout the reserve system and the surrounding matrix.