Habitat Ecology & Management III

Contributed Oral

Toward a Shared Understanding of Climate-informed Restoration on America’s National Forests
Patty Glick, Bruce Stein, Kimberly Hall

A rapidly changing climate, including rising temperatures, changing precipitation patterns, and more extreme storms, is having profound consequences for America’s national forests. Climate-related impacts on forest systems include larger and more severe disturbances (e.g., wildfires, drought, insect outbreaks), shifts in tree species ranges and forest composition, and changes in forest dynamics and regeneration capacity. These impacts have significant implications for the effectiveness of conventional forest restoration efforts, such as reliance on historical conditions as the benchmark for restoration outcomes. The U.S. Forest Service has made considerable progress over the past decade in understanding the effects of climate change on forest ecosystems and identifying approaches for better incorporating climate adaptation and mitigation principles in its work. Nonetheless, varying perspectives on what climate change means for ecological restoration in practice continue to pose challenges in national forest planning and management. We carried out a review and synthesis of the science and developed a set of principles to help build a shared understanding of climate-informed and ecologically appropriate forest restoration. This work is intended to serve as a foundation for continued dialogue and collaboration among Forest Service managers and their partners in the federal, state, tribal, nonprofit, and private sectors to enhance the application of these approaches on the ground.

Assessing Effects of Habitat Amount Vs. Configuration on Avian Diversity in Managed Pine Landscapes
Craig Sklarczyk, Kristine Evans, Dana Morin, Daniel Greene, Raymond Iglay

The large spatial footprint of pine forests managed for timber production in the Southeastern Coastal Plain ecoregion provides resources for resident and migratory bird species across a range of habitats. Given managed pine forests extensive coverage and a growing demand for forest products, it is critical to enhance our understanding of how forest management activities influence avian diversity at the landscape scale to achieve conservation objectives. Typically, these working forests are managed as a matrix of different stand age classes, but little is known about how spatial patterning of those stands influence bird diversity and abundance. There is debate among landscape ecologists as to whether total amount of habitat, regardless of spatial pattern (i.e., configuration), drives species richness and abundance in a landscape. The mosaic of forest stand ages in southeastern managed pine systems allows us to readily evaluate effects of habitat amount vs. configuration on wildlife communities. We examined breeding-season avian communities in regenerating and mid-late successional managed loblolly pine stands in east-central Mississippi from 2019-2020. We used a Bayesian hierarchical modeling framework, which combined distance-sampling and time-removal methods, to address availability and perceptibility. Across early-successional and mature pine bird communities, landscape covariates had minimal effects. When we narrowed our analysis to declining priority species, we found substantial effects of landscape patterning. Proximity of habitat patches seemed to be most influential on predicted abundance of priority species (e.g. Eastern Towhee, Red-headed Woodpecker, and Eastern Kingbird) within our working pine forests. However, proportion of that habitat on the landscape should not be ignored for area-sensitive species. We suggest associations with habitat amount and configuration are species-specific. By improving our understanding of how spatial patterning influences birds in working pine forests, managers can better integrate conservation measures, particularly for at-risk species, while simultaneously achieving land use objectives.

Spatial and Temporal Interactions between Jaguars and Pumas in the Sierra Gorda Biosphere Reserve, Querétaro, Mexico
Diana Nieves Rocha, Carlos A Lopez Gonzalez

Jaguars (Panthera onca) and pumas (Puma concolor) are sympatric species that coexist throughout their distribution in the Neotropics. The coexistence of these cats has been the subject of many studies in order to understand the mechanisms behind it. Therefore, our objective was to analyze whether the coexistence of jaguars and pumas within the Sierra Gorda Biosphere Reserve is explained by a spatio-temporal separation between both felids or if this coexistence is driven by the habits of their potential prey. To achieve this, we used occupancy models (single season – single species) and activity pattern analysis with the independent photographic records of 145 camera-traps over 2013,2015, 2016 and 2018 (4 years). We used forest cover, distance to towns, elevation, slope, density of humans, white-tailed deer occupancy, livestock density and the presence of pumas for jaguar occupancy models. We found 38 records of jaguars and 39 of pumas. We determined that jaguar detection (p) was 0.117 (0.022) and occupancy (psi) was 0.255 (0.056) while puma p was 0.089 (0.013) and psi was 0.619 (0.085). We found that jaguar occupancy had a negative relation to elevation and a positive relation with distance to the nearest human localities and puma presence. Puma occupancy showed a negative correlation, but with a less pronounced slope with altitude and white-tailed deer occupancy. Activity patterns of both felids were active throughout the day, with night-crepuscular activity peaks and an overlap coefficient of 72%. Pumas had a 70% temporal overlap with white-tailed deer. The results indicates that the coexistence between these felids is due to a temporal segregation given by the peaks of activity and a spatial partition where the prey, in this case the white-tailed deer, are significantly influencing the habits of the pumas, which may explain why the dominance in de occupancy of pumas into the reserve. 

Predicted Distribution and Vegetation Associations of a Rare and Understudied Forest Carnivore: Humboldt Martens
Katie Moriarty, Matthew Delheimer, Joel Thompson, Brent Barry, Mark Linnell, Taal Levi, Keith Hamm, Desiree Early, Holly Gamblin, Micaela Szykman Gunther, Jordan Ellison, Janet Prevéy, Jennifer Hartman, Raymond Davis

Many mammalian species have experienced range contractions. Following a reduction in distribution that has resulted in apparently small and geographically isolated populations, the Humboldt marten (Martes caurina humboldtensis) was recently designated as federally threatened as a Distinct Population Segment of coastal martens. This subspecies of Pacific marten occurring in coastal Oregon and northern California appears unlike martens that occur in snow-associated regions. Specifically, vegetation associations appear to differ widely between Humboldt marten populations. Here, we assessed the predicted contemporary distribution of Humboldt martens. We interpreted our findings as hypotheses correlated with the subspecies’ niche to inform strategic conservation actions. Lastly, we summarized fine-scale vegetation data at marten scat, rest, and den locations. We modeled Humboldt marten distribution using Maxent. We spatially-thinned 10,229 marten locations (1996–2020), applying a minimum distance of 500-m between locations and resulting in 384 locations. We independently optimized the spatial scale of each variable and focused development of model variables on biotic associations (e.g., hypothesized relationships with forest conditions), given that abiotic factors such as precipitation are largely static and not alterable within a management context. Humboldt marten locations were positively associated with increased shrub cover (salal (Gautheria shallon)), mast producing trees (e.g., tanoak, Notholithocarpus densiflorus), increased pine (Pinus sp.) proportion of total basal area, annual precipitation, low and high amounts of canopy cover, flat and steep slopes, and cooler August temperatures. Unlike other recent literature, we found little evidence that Humboldt martens were associated with old-growth structural indices. The influence of fine-scale vegetation data was variable and inconsistent. This case study provides an example of how limited information on rare or lesser-known species can lead to differing interpretations, emphasizing the need for study-level replication in ecology. Humboldt marten conservation would benefit from continued survey effort to clarify range extent, population sizes, and fine-scale habitat use.

What Does the Fox Say? An Assessment of Space Use and Movement for Rocky Mountain Red Fox Within Grand Teton National Park
Emily Burkholder, Joseph Holbrook, John Stephenson, David Gustine, Sarah Hegg

In the Anthropocene, conflicts between humans and wildlife are unavoidable. The National Park Service is dedicated to the preservation of intact landscapes and wildlife populations, while also hosting millions of visitors each year. In Grand Teton National Park (GTNP) 3.3 million visitors were recorded during 2020. Negative human-wildlife interactions and food-conditioned wildlife have become a major concern in areas such as GTNP, yet fundamental questions at the interface of humans and wildlife remain. Here, we evaluated how human structures and temporal variation in human activity influenced space use and movement of Rocky Mountain red fox (Vulpes vulpes macroura) within GTNP.  Rocky Mountain red fox is a high-elevation subspecies of the common red fox (Vulpes vulpes), and native to North America. During 2016 – 2021, we captured and GPS collared 21 individuals (12 males, 9 females) and evaluated spatiotemporal shifts in home range characteristics as well as movement patterns. We discovered substantial individual-level variation in movement, and identified differing effects of human activity. For instance, some individuals acclimated and exploited areas of high human concentrations, while others remained distant and focused home ranges and core areas away from humans. These differences were not correlated with age or sex of foxes, perhaps indicating intraspecific variation in boldness or carryover effect of parental influence (being born and raised around humans) may be responsible for differences in movement behavior. Regardless, this work provides a deeper understanding of red fox ecology concerning variation in space use associated with humans within GTNP and a baseline for implementing experimental measures with an aim of facilitating both human access to National Parks while limiting negative human-fox interactions. 

Statewide Dispersal Corridor Identification for Florida Black Bears
Erin Poor, Jennifer Mullinax

Habitat loss and degradation is one of the leading causes of carnivore species declines globally. In many landscapes, a growing human population has resulted in fragmented natural areas and carnivore populations, leading to decreased connectivity and gene flow. In the US, black bears (Ursus americanus) have made significant recoveries and in some areas have expanded into human dominated landscapes, increasing chances of conflict. The State of Florida has focused on recovering the once-threatened Florida black bear (Ursus americanus floridanus). This statewide population, once located in several distinct subpopulations throughout the state, remains genetically fragmented despite an increase in population numbers. To aid with managing a potentially expanding population and regaining genetic connectivity, in this study we used Circuitscape v. 4 (implemented in Julia) to identify statewide potential dispersal corridors among subpopulations (occupied areas) and unoccupied areas within suitable habitat, at 120 m resolution. We used a previously published ensemble habitat suitability model based on >80,000 historic bear locations as a resistance layer and fine-scale GPS collar data for corridor model validation. In addition, we used historic black bear mortality data to identify specific areas for targeted management interventions, such as road crossing structures, within identified dispersal corridors. This is the first statewide corridor model for Florida black bears, allowing identification of priority dispersal areas, recommendation of new lands for possible protection, and further aiding the recovery of the Florida black bear.

Patch Characteristics and Domestic Dogs Differentially Affect Carnivore Space Use in Fragmented Landscapes in Southern Chile
Rumaan Malhotra, Jaime Jiménez, Nyeema C. Harris

In an increasingly anthropogenic world, species face multiple interacting threats. Habitat fragmentation and domestic dogs are two perturbations threatening terrestrial mammals globally. Our aim was to determine if (1) the spatial use of domestic dogs increases with habitat destruction and (2) whether domestic dogs and habitat destruction drive the spatial use of native carnivores in a heavily degraded agricultural landscape. We implemented a camera trap survey in a fragmented landscape comprised of native forest patches amidst a matrix of pastureland in Los Lagos, Chile. We used single-species occupancy models to assess the impact of domestic dogs and habitat destruction on three mesocarnivores – the foxes, culpeo (Lycalopex culpaeus) and chilla (Lycalopex griseus) and the wild cat güiña (Leopardus guigna). Additionally, we compared temporal overlap of all study species (including domestic dogs). The occupancy of domestic dogs increased with habitat loss. Detection rates for both the foxes increased with domestic dog occupancy, while factors driving occupancy differed for each of the native species. We found that a 12% projected increase in domestic dog occupancy negatively impacted the spatial use of the culpeo. In contrast, domestic dog occupancy had no effect/was positively correlated with chilla spatial use. Fragmentation was a positive driver for chilla occupancy. The güiña did not respond to fragmentation and other habitat covariates or to domestic dog occupancy. All native carnivore species were primarily nocturnal, while the domestic dog was almost entirely diurnal. We highlight that the effects of domestic dogs or habitat destruction are not ubiquitous across the carnivore guild, with native species showing varied tolerance. However, future conditions of increased fragmentation and habitat loss will likely increase the potential contact between domestic dogs and native carnivores. Our work is an example of how landscape structure may impact native species while also mediating their interactions with invasive species. 

Landscape Restoration Mitigates Biodiversity Loss of Grassland Birds
David Pavlacky, Adam Green, Luke George, Rich Iovanna, Anne Bartuszevige, Maureen Correll, Arvind Panjabi, Brandt Ryder

The decline of biodiversity from anthropogenic landscape modification is among the most pressing conservation problems world-wide.  In North America, recovery of the grassland avifauna is among the highest conservation priorities.  Because most of the Great Plains are privately owned, the recovery of grassland bird populations depends on conservation strategies that integrate social, economic, and biodiversity objectives.  The Conservation Reserve Program (CRP) is a voluntary program for private agricultural producers that provides financial incentives to take cropland out of production and restore perennial grassland.  The research objectives were to 1) determine how apparent habitat loss has affected spatial patterns of grassland bird biodiversity, 2) evaluate the effectiveness of CRP for offsetting biodiversity declines of grassland birds and 3) develop spatially explicit predictions to estimate the biodiversity benefit of adding CRP to landscapes impacted by habitat loss.  We used the Integrated Monitoring in Bird Conservation Regions program to evaluate hypotheses for the effects of habitat loss and restoration on occupancy and species richness of grassland specialists within a continuum modelling framework.  We found the odds of community occupancy declined by 37% for every 1 unit decrease in grassland availability and increased by 20% for every unit increase in CRP land cover.  There was 17% turnover in species composition between intact grasslands and CRP landscapes, suggesting grasslands restored by CRP retained considerable, but incomplete representation of biodiversity in agricultural landscapes.  Spatially explicit predictions indicated absolute conservation outcomes were greatest at high latitudes in regions with high biodiversity, whereas the relative outcomes were greater at low latitudes in highly modified landscapes.  By evaluating community-wide responses to landscape modification and CRP restoration at bioregional scales, our study fills key information gaps for developing collaborative strategies, and balancing conservation of avian biodiversity and social well-being in agricultural production landscapes of the Great Plains.

Comparison between Elk Forage in Managed Wildlife Openings and Silviculture Openings in a Mixed Hardwood Forest
Anna Brose, Jennifer Merems, Tim Van Deelen, Jennifer Price Tack, Joshua Speigel

Elk (Cervus elaphus) have been reintroduced across portions of their historic range in the eastern United States; however, the disruption of natural disturbance regimes has resulted the use of timber harvests and wildlife openings to maintain early seral areas rich in forbs and grasses. We compared the quantity and composition of elk forage in areas logged within the previous two years and in managed wildlife openings that are routinely mowed and sprayed with herbicides to reduce woody encroachment in the mixed hardwood forest of northern Wisconsin, USA. We sampled sites (n ≈ 50) across a gradient of summer elk use with the objective of informing habitat management priorities to benefit elk. Preliminary results indicate that forage biomass is similar between silviculture and wildlife openings, but plant species composition is different. During the summer of 2020, we observed that elk use was higher in silviculture openings with greater herbaceous cover and less woody growth, and in silviculture openings with higher plant species diversity. Our results provide guidance for habitat and timber management decisions that support elk populations in mixed hardwood forests.

Contributed Oral
Location: Virtual Date: November 3, 2021 Time: 4:00 pm - 5:00 pm