Wildlife Habitat Quality Research Articles

Spatio-Temporal Changes in Wildlife Habitat Quality in the Middle and Lower Reaches of the Yangtze River from 1980 to 2100 Based on the InVEST Model

The Yangtze River (YZR) regions have experienced rapid changes after opening up to economic reforms, and human activities have changed the land cover, ecology, and wildlife habitat quality. However, the specific ways in which those influencing factors changed the habitat quality during different periods remain unknown. This study assessed the wildlife habitat quality of the middle and lower YZR in the past (1980–2018) and in future scenarios (2050, 2100). We analyzed the relationships between habitat quality and various topological social-economic factors, and then mapped and evaluated the changes in habitat quality by using the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) model. The results show that the slope (R = 0.502, P < 0.01, in 2015), elevation (R = 0.003, P < 0.05, in 2015), population density (R = –0.299, P < 0.01, in 2015), and NDVI (R = 0.366, P < 0.01, in 2015) in the study area were significantly correlated with habitat quality from 2000 to 2015. During the period of 1980–2018, 61.93% of the study area experienced habitat degradation and 38.07% of the study area had improved habitat quality. In the future, the habitat quality of the study area will decline under either the A2 scenario (high level of population density, low environmental technology input, and high traditional energy cost) or the B2 scenario (medium level of population density, medium green technology and lack of cooperation of regional governments). The results also showed that habitat in the lower reaches or north of the YZR had degraded more than in the middle reaches or the south of YZR. Therefore, regional development should put more effort into environmental protection, curb population growth, and encourage green technology innovation. Inter-province cooperation is necessary when dealing with ecological problems. This study can serve as a scientific reference for regional wildlife protection and similar investigations in different areas.

Range-wide assessment of the impact of China's nature reserves on giant panda habitat quality

Protected areas (PAs) form the backbone of global conservation efforts. Although many studies have evaluated the impact of PAs on land cover, human disturbances, and people's welfare, PAs' impact on wildlife habitat quality remains poorly understood. By integrating wildlife habitat mapping and information of 2183 rural households, we assessed the impacts of nature reserves (a type of PAs) across the entire geographic range of giant pandas (Ailuropoda melanoleuca) on panda habitat suitability change between 2001 and 2013 using the matching approach. We found the impact of nature reserves is concentrated in areas susceptible to human pressure, where 65% of the habitat suitability increase is attributable to the nature reserves' protection. The impact of nature reserves has spilled over to nearby unprotected areas and enhanced habitat suitability there. Nature reserves supported by the central government showed higher performance in improving habitat suitability than their counterparts supported by local governments. Older nature reserves perform better than those established more recently. Our results also show that local households' participation in tourism and labor migration (people temporarily leaving to work in cities) enhanced the ability of nature reserves to improve habitat suitability. These results and methods provide valuable information and tools to support effective management of PAs to enhance the habitat quality of giant pandas and other wildlife species in China and elsewhere.

Harnessing terrestrial laser scanning to predict understory biomass in temperate mixed forests

Forest understory vegetation plays an important role in providing food, nutrition and habitat for wildlife. The impact of wildlife foraging on forest understory biomass are often subtle processes that are difficult to capture using traditional field measurements. Field measurements are labor-intensive and impractical to cover and detect understory biomass changes at an extensive range with fine spatial resolution, thereby affecting the accuracy of habitat quality and food availability assessment for wildlife. Terrestrial Laser Scanning (TLS) is considered to have potential to improve the accuracy of understory biomass prediction, allowing for detailed monitoring of biomass changes under the influence of wildlife at fine scale. In this study, we first developed an efficient method to predict forest understory biomass by using variables from TLS with regression models, and second, we compared the prediction accuracy between TLS-based variables and field-measured variables. Third, the optimal models with TLS-based variables were applied to map and quantify the effect of herbivores density on understory biomass in temperate forests in northeastern China. Our results demonstrated that TLS-derived data were more accurate than field measurements in predicting understory biomass, that TLS-derived canopy cover yielded the highest herb layer biomass estimation accuracy (R2 = 0.72, RMSE = 12.73 g/m2), and that TLS-derived vegetation volume obtained the highest accuracy assessment for the shrub layer biomass prediction (R2 = 0.69, RMSE = 43.64 g/m2). There was a significant difference in the understory herb layer biomass in different deer-density plots, but no significant difference in shrub layer biomass. To quantify biomass changes in different plots, consistent monitoring method is needed, TLS data demonstrated the potential to capture and accurately quantify the biomass variation from forest understory. As tool for monitoring understory, TLS can be used as a supplementary to traditional understory monitoring methods to guide forest management policies and wildlife conservation strategies.

Rapid Assessment of Habitat Quality for Nonbreeding Ducks in Northeast Colorado

AbstractThe ability to assess habitat quality for wildlife is important for evaluating the effectiveness of, or need for, habitat management. Habitat assessment methods generally involve a tradeoff between usability and explanatory power and finding the optimal balance can be challenging. In 2013, Colorado Parks and Wildlife developed a habitat quality rapid assessment method for dabbling ducks (Anatidae) that field personnel used to evaluate wetland management projects. The assessment involves six multiple-choice questions related to vegetation and wetland structure and is designed to be used by people with little wetland ecology training. I tested the ability of the assessment to predict duck density and food availability at 44 sites in northeastern Colorado. I found that the procedure explained 10–22% of the variability in food availability and was not a good predictor of duck density. By altering the grouping of answers as well as the weight of each question, score associated with each answer, and substituting a new question relating to percentage of coverage of duck food–producing plants, the ability of the assessment to explain food availability increased to 30%. Overall, the assessment may be sufficient for relative indication of habitat quality, but if wildlife managers desire precise predictions, further refinement is necessary.

Distance effects of gas field infrastructure on pygmy rabbits in southwestern Wyoming

AbstractAs domestic energy development activity continues in the western United States, wildlife conservation planning in affected regions is increasingly important. The geologic basins where oil and gas energy exploration is occurring are primarily sagebrush steppe rangelands. Sagebrush steppe habitats may support more than 20 vertebrate species of conservation concern, and for many of these species, information is lacking on the effects of gas energy development. In earlier work, we demonstrated a negative relationship among development density of gas field infrastructure and pygmy rabbits (Brachylagus idahoensis). We now examine the spatial relationship among gas field infrastructure, pygmy rabbits, and their habitat on four major gas fields in southwest Wyoming. Using data collected from 120 plots over three years (2011–2013) and 2012 National Agriculture Imagery Program (NAIP) imagery, we evaluated (1) whether well pads are more likely to be located in areas of pygmy rabbit habitat, (2) whether the presence and abundance of pygmy rabbits are related to distance from infrastructure, and, if so, (3) how much of the total surface area on a gas field is affected. Well pads on three gas fields occurred in higher quality pygmy rabbit habitat than did a set of randomly generated points, and the abundance and probability of pygmy rabbits being present were lower within approximately 0.5–1.5 km of the nearest road and 2 km of well pads and utilities. Buffering a digital layer of roads and well pads on one gas field revealed that nearly 82% of the (4417 km2) surface area was within 1 km of infrastructure, and over 95% of the gas field surface area was within 2 km. This need not be the case on future gas fields. Directional and horizontal well drilling technologies now make it possible for gas to be recovered from a greater area per well pad, enabling future gas field developments that require fewer well pads, roads, and pipeline corridors. Such changes would enable increased well pad spacing and provide the opportunity to locate gas field infrastructure in areas of poor quality wildlife habitat, avoid high priority habitat, and conserve a greater amount of on‐field wildlife habitat overall.

Wildlife response to recreational trail building: An experimental method and Appalachian case study

Trail networks are common infrastructure in protected areas for visitors to exercise, connect with nature, and learn about natural and cultural resources. However, there are concerns that the presence and construction of trails affect the quality of wildlife habitats, extending human disturbance into secluded areas. In this study, we developed a before-after control-impact experimental design to investigate the impacts of new trail construction on six terrestrial vertebrate species in an Appalachian protected area in the U.S. Using camera traps, we monitored animal use of the study area before, during, and after construction, on the trail, near the trail, and at a control site. Our results indicate statistically significant impacts of trail building and presence on four common species. During trail construction, white-tailed deer (Odocoileus virginianus) and coyotes (Canis latrans) decreased their activity on and/or near the trail, while raccoons (Procyon lotor) increased activity on the trail. These three species returned to the area at pre-building levels once trail construction was complete. After trail building, eastern gray squirrel (Sciurus carolinensis) showed decreased use of the trail area. We also observed altered timing of daily activity patterns for squirrels and deer, both diurnal species. Deer activity became more spread throughout the day within the near-trail zone during construction. After the trail was complete, squirrels shifted activity to earlier in the day, after sunrise and prior to the peak of recreational activity. We conclude that while trail building may alter habitat quality for some species, this mostly occurred during the construction phase, and was fairly minor for our study species. To minimize impacts, we suggest that trail building be restricted to a short time period during a season when species of concern are least sensitive. Our use of control sites allowed us to distinguish experimental effects from natural population fluctuations, and should serve as a foundation for future work investigating the effects of trails and other linear human disturbances on wildlife communities, especially in sensitive habitats and ecosystems.

Emergent conservation outcomes of shared risk perception in human-wildlife systems.

Human perception of risks related to economic damages caused by nearby wildlife can be transmitted through social networks. Understanding how sharing risk information within a human community alters the spatial dynamics of human-wildlife interactions has important implications for the design and implementation of effective conservation actions. We developed an agent-based model that simulates farmer livelihood decisions and activities in an agricultural landscape shared with a population of a generic wildlife species (wildlife-human interactions in shared landscapes [WHISL]). In the model, based on risk perception and economic information, farmers decide how much labor to allocate to farming and whether and where to exclude wildlife from their farms (e.g., through fencing, trenches, or vegetation thinning). In scenarios where the risk perception of farmers was strongly influenced by other farmers, exclusion of wildlife was widespread, resulting in decreased quality of wildlife habitat and frequency of wildlife damages across the landscape. When economic losses from encounters with wildlife were high, perception of risk increased and led to highly synchronous behaviors by farmers in space and time. Interactions between wildlife and farmers sometimes led to a spillover effect of wildlife damage displaced from socially and spatially connected communities to less connected neighboring farms. The WHISL model is a useful conservation-planning tool because it provides a test bed for theories and predictions about human-wildlife dynamics across a range of different agricultural landscapes.

High Arctic Vegetation Change Mediated by Hydrological Conditions

Increasing air temperatures are driving widespread changes to Arctic vegetation. In the high Arctic, these changes are patchy and the causes of heterogeneity are not well understood. In this study, we explore the determinants of high Arctic vegetation change over the last three decades on Banks Island, Northwest Territories. We used Landsat imagery (1984–2014) to map long-term trends in vegetation productivity and regional spatial data to investigate the relationships between trends in productivity and terrain position. Field sampling investigated vegetation community composition in different habitat types. Our analysis shows that vegetation productivity changes are substantial on Banks Island, where productivity has increased across about 80% of the study area. Rising productivity levels can be attributed to increasing biomass of the plant communities in both upland and lowland habitats. Our analysis also shows that the magnitude of greening is mediated by terrain characteristics related to soil moisture. Shifts in tundra vegetation will impact wildlife habitat quality, surface energy balance, permafrost dynamics, and the carbon cycle; additional research is needed to explore the effects of more productive vegetation communities on these processes in the high Arctic.

Global shifts in mammalian population trends reveal key predictors of virus spillover risk.

Emerging infectious diseases in humans are frequently caused by pathogens originating from animal hosts, and zoonotic disease outbreaks present a major challenge to global health. To investigate drivers of virus spillover, we evaluated the number of viruses mammalian species have shared with humans. We discovered that the number of zoonotic viruses detected in mammalian species scales positively with global species abundance, suggesting that virus transmission risk has been highest from animal species that have increased in abundance and even expanded their range by adapting to human-dominated landscapes. Domesticated species, primates and bats were identified as having more zoonotic viruses than other species. Among threatened wildlife species, those with population reductions owing to exploitation and loss of habitat shared more viruses with humans. Exploitation of wildlife through hunting and trade facilitates close contact between wildlife and humans, and our findings provide further evidence that exploitation, as well as anthropogenic activities that have caused losses in wildlife habitat quality, have increased opportunities for animal–human interactions and facilitated zoonotic disease transmission. Our study provides new evidence for assessing spillover risk from mammalian species and highlights convergent processes whereby the causes of wildlife population declines have facilitated the transmission of animal viruses to humans.

Shorebird predation on benthic invertebrates after shrimp-pond harvesting: Implications for semi-intensive aquaculture management

How to improve habitat quality for wildlife is of particular importance in areas dedicated to food production, due to increasing pressures of global demands associated to human population growth. Semi-intensive aquaculture ponds can provide a potentially important foraging habitat for migratory shorebirds throughout the non-breeding season. Therefore, understanding the availability of benthic invertebrates in aquaculture ponds will help to identify proper management decisions for shorebird conservation. We used an exclosure experiment during the first three days after shrimp harvesting at semi-intensive aquaculture ponds in north-west Mexico to assess shorebird predation on benthic invertebrates. We found that shorebird predation did not deplete total benthic invertebrate density (particularly polychaete worms), but significantly affected the prey size distributions and biomass in the ponds during a short-time window of just three days. Shorebirds removed 0.6 g ash-free dry weight m−2, equivalent to 43% of the initial biomass and showed high selectivity for polychaetes larger than >40 mm as prey, potentially explaining the absence of large polychaetes at the end of the experiment. This depletion was the likely cause of the daily decrease observed in overall density of foraging shorebirds at recently harvested ponds. These results can serve to identify management actions that allow an extended use of semi-intensive aquaculture ponds as foraging sites for migratory shorebirds during the non-breeding season, with potential applications to develop standards for a friendlier aquaculture management.

Analyzing the provision of ecosystem services by conservation easements and other protected and non-protected areas in the Upper Chattahoochee Watershed

A conservation easement (CE) legally places a permanent restriction on the development of a private land parcel, and in turn, can provide tax benefits to the landowner. We used the modular toolset InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) to quantify provision of five ecosystem services (ESs) (carbon storage, wildlife habitat quality, nitrogen, phosphorus, and sediment exports) provided by CEs and other land typologies (Simulated Parcels, 1 km Buffer area, Watershed Average, Federal, State and Local Protected Areas) within the Upper Chattahoochee Watershed (UCW), which provides 72% of drinking water to about six million residents of the Atlanta Metropolitan Area and is experiencing one of fastest urban growth of the United States. Simulated Parcels would represent the land cover of CEs if the development restrictions were not in place. We conducted the analysis for 2001, 2006, 2011 and 2016. We aggregated all ESs into one index. Overall, CEs provided higher levels of ESs relative to the Simulated Parcels, 1 km Buffer, Watershed Average, and Local Protected Areas. However, the ESs from CEs were lower relative to Federal and State Protected Areas. Our results suggest that CEs are effective in ensuring the continuance of ESs within the UCW.

Investigation of bed and den site selection by American black bears (Ursus americanus) in a landscape impacted by forest restoration treatments and wildfires

The combined effects of long-term fire suppression, logging, and overgrazing have negatively impacted many southwestern U.S. forests, resulting in decreased habitat quality for wildlife, and more frequent and severe wildfires. In response, land management agencies are implementing large-scale forest restoration treatments, but data on how wildlife respond to restoration treatments and wildfires are often limited. We investigated bed and den site selection of American black bears (Ursus americanus) using GPS location data and a use/available study design to assess the influence of habitat characteristics, including wildfires, prescribed burns, and thinning treatments on bed and den site selection in the Jemez Mountains, New Mexico. The most supported models suggested that black bears were more likely to select bed sites with a combination of low horizontal visibility (β = −0.007, SE = 0.002; P = 0.002) and high stand basal area (β = 0.013, SE = 0.005; P = 0.004). The highest-ranking model for den site selection indicated that black bears were more likely to select den sites with low horizontal visibility (β = −0.0102, SE = 0.004; P = 0.006). Black bears used all disturbed sites to varying degrees (45% of study area), although 48% of bed sites were located in undisturbed habitat (55% of study area) while only 11% and 2% of bed sites were located in thinned and prescribed burn sites, respectively. Thirty-nine percent of bed sites were located in previous wildfire locations; however, 67% of these sites were in areas with low burn severity. Thirty-eight percent of den sites were located in previously disturbed habitat, 8 of these sites were burned by wildfires. In order to develop effective management plans for black bears, it is essential to understand responses to landscape-scale habitat disturbances due to wildfires and restoration activities, all of which are becoming more prevalent and widespread across southwestern forests. Accounting for the timing, size, and proximity of future restoration efforts would aid in mitigating potential short-term negative effects on black bears.

Temporal road closures improve habitat quality for wildlife

Increasing levels of human activity threaten wildlife populations through direct mortality, habitat degradation, and habitat fragmentation. Area closures can improve habitat quality for wildlife, but may be difficult to achieve where tourism or other economic drivers are a priority. Temporal closures that limit human use during specific times of day have potential to increase habitat quality for wildlife, while continuing to provide opportunities for human use. However, the effectiveness of daily temporal closures has not been tested. We assessed how implementation of a temporal road closure affected wildlife movements in Banff National Park. Parks Canada closed a popular 17 km stretch of road between 2000 and 0800 hours to improve habitat quality for wildlife. We assessed the effectiveness of the closure on nine mammal species using three sets of data: remote cameras, road surveys, and grizzly bear (Ursus arctos) GPS data. In all three analyses, wildlife detection rates on the road doubled during the closure while remaining unchanged in reference areas. Our strong and consistent results suggest temporal closures are an important conservation tool that can increase habitat quality for wildlife while minimizing effects on people.

Cattle select against the invasive grass tall fescue in heterogeneous pastures managed with prescribed fire

AbstractTall fescue (Festuca arundinacea) is a Eurasian forage grass extensively planted in the United States. However, an endophytic fungus in tall fescue, Epichloë coenophiala, causes health problems in cattle. We predicted that cattle prefer to graze alternative forages when available. We also predicted that cattle use tall fescue more intensively in recently burned areas, as fire can increase forage quality. We tested these predictions in four diverse‐forage pastures in Iowa, comparing use by cattle of tall fescue and four alternative forages (non‐fescue cool‐season grasses, native warm‐season grasses, non‐leguminous forbs and legumes) to their availabilities at the pasture scale. We also examined how tall fescue influences the distribution of grazing at a fine scale (0.1‐m2 quadrats). Tall fescue was the most abundant forage (46% of plants), but composed only 26% of grazed vegetation. In contrast, legumes composed 12% of available forage but 25% of grazed vegetation. Other forages were used in proportion to availability. At a fine scale, total grazing frequency (proportion of plants grazed) was lower in quadrats containing abundant tall fescue, and higher in quadrats with abundant warm‐season grasses. Grazing frequency of tall fescue and other cool‐season grasses was greatest in recently burned quadrats, but total grazing frequency did not increase after burning. Our results show that although cattle graze tall fescue, particularly following burns, they limit their use of this grass. Given that tall fescue is underused, creates health risks for cattle, and degrades wildlife habitat quality, it may be advisable to reduce tall fescue in pastures.

Ecological and social consequences of bison reintroduction in Colorado

Bison were instrumental in shaping North America's Great Plains. Interest in restoring this iconic species and their ecological role in grassland ecosystems is rapidly gaining momentum. To evaluate the potential for bison to enhance habitat quality for wildlife and catalyze public engagement in grassland conservation, we assessed both the ecological and social effects of a recent bison reintroduction (2015) to northern Colorado. Specifically, we explored the effect of bison reintroduction on: (a) bird density and habitat use, (b) mammal habitat use, (c) vegetation composition and structure, and (d) visitor connectedness, known as place attachment, to a shortgrass prairie. We predicted that bison reintroduction would reduce cover and height of some grasses and shrubs, which would increase density and habitat use for obligate shortgrass prairie birds, and increase habitat use for coyote and lagomorphs. In addition, we predicted that visitors would express stronger place attachment to this grassland once bison were reintroduced. To measure ecological and social responses, we surveyed birds, mammals, and plants; and conducted structured visitor surveys before and after bison reintroduction. We found few short‐term effects of bison on grassland bird density and habitat use, mammal habitat use, and vegetation composition and structure. However, we measured a significant increase in visitor place attachment to the grassland site 1 year after bison reintroduction. Our results suggest that a new bison reintroduction may have immediate positive benefits for connecting people to conservation, and that the ecological and social effects may unfold over different time scales. We recommend that future bison reintroduction efforts monitor ecological and social outcomes to advance reintroduction biology.

The influence of food availability, quality and body size on patch selection of coexisting grazer ungulates in western Serengeti National Park

Context Differences in body size and mouth morphologies influence dietary resource separation among savanna ungulates, and this influences their distribution across landscape. Aim The aim was to understand the influence of body size and mouth morphology differences on both diet and patch selection by ungulate species in western Serengeti. Two hypotheses were tested: (1) for ungulate species, the relative body sizes and muzzle widths (mean muzzle width range: 3.1- 9.85) relate directly to food biomass, and to quality of diets selected in the wet season when food is abundant; (2) in the wet season, if food is not limiting, similar-sized species should exhibit greater dietary niche overlap than ungulate species that differ greatly in body size and muzzle width; moreover, similar-sized species exhibit less dietary niche overlap than ungulate species that differ greatly in body size. Methods In the western Serengeti ecosystem, road transects and direct observation were used to obtain data on the distribution and diet of five ungulate species namely buffalo, zebra, wildebeest, topi and impala; which have of varying sizes (range: 70–630kg) feeding in three different vegetation types. Grassland biomass, structure, nutrient content and ungulate use were measured at sites along transects. Key Results Results indicated that large-bodied ungulates utilised patches of greater food abundance compared with those of smaller ungulates. Body mass was also negatively correlated with diet quality, so that smaller animals ate higher protein and lower-fibre foods, as predicted. Diet niche overlap (niche similarity) showed a strong positive relationship with body mass differences among ungulate species, in support of the second of the two predictions from this hypothesis, namely that dissimilarly sized species could eat the same food. Conclusion Overall, the results suggest that in this savanna system, variation in ungulate body size influences resource separation even in the food-abundant wet season, and that this helps multiple species to co-exist. Implications Implementing more focused conservation strategies will improve wildlife habitat quality by integrating fire as a forage management tool with grazing preferences to promote forage heterogeneity in protected areas.

More than climate? Predictors of tree canopy height vary with scale in complex terrain, Sierra Nevada, CA (USA)

Tall trees and vertical forest structure are associated with increased productivity, biomass and wildlife habitat quality. While climate has been widely hypothesized to control forest structure at broad scales, other variables could be key at fine scales, and are associated with forest management. In this study we identify the environmental conditions (climate, topography, soils) associated with increased tree height across spatial scales using airborne Light Detection and Ranging (LiDAR) data to measure canopy height. The study was conducted over a large elevational gradient from 200 to 3000 m in the Sierra Nevada Mountains (CA, USA) spanning sparse oak woodlands to closed canopy conifer forests. We developed Generalized Boosted Models (GBMs) of forest height, ranking predictor variable importance against Maximum Canopy Height (CHMax) at six spatial scales (25, 50, 100, 250, 500, 1000 m). In our study area, climate variables such as the climatic water deficit and mean annual precipitation were more strongly correlated with CHmax (18–52% relative importance) than soil and topographic variables, and models at intermediate (50–500 m) scales explained the most variance in CHMax (R2 0.77–0.83). Certain soil variables such as soil bulk density and pH, as well as topographic variables such as the topographic wetness index, slope curvature and potential solar radiation, showed consistent, strong associations with canopy structure across the gradient, but these relationships were scale dependent. Topography played a greater role in predicting forest structure at fine spatial scales, while climate variables dominated our models, particularly at coarse scales. Our results indicate that multiple abiotic factors are associated with increased maximum tree height; climatic water balance is most strongly associated with this component of forest structure but varies across all spatial scales examined (6.9–54.8% relative importance), while variables related to topography also explain variance in tree height across the elevational gradient, particularly at finer spatial scales (37.15%, 20.26% relative importance at 25, 50 m scales respectively).

Grizzly bear response to spatio‐temporal variability in human recreational activity

Abstract Outdoor recreation on trail networks is a growing form of disturbance for wildlife. However, few studies have examined behavioural responses by large carnivores to motorised and non‐motorised recreational activity — a knowledge gap that has implications for the success of human access management aimed at improving habitat quality for wildlife. We used an integrated step selection analysis of grizzly bear (Ursus arctos) radiotelemetry data and a spatio‐temporal model of motorised and non‐motorised human recreational activity to examine how human recreational activity on trails affects both habitat selection and movement behaviour of individual bears. Grizzly bears were captured and radiocollared in the west‐central Alberta Rocky Mountains and Foothills, and trail cameras were deployed on trails to obtain data on human recreational activity. We found that models including data on recreational activity outperformed trail‐proximity models when interactions with movement covariates were included. Responses were highly variable among individuals and across classes: males, females, and females with cubs. Male and solitary female grizzly bears increased avoidance of trails with a high probability of motorised activity as well as displaying increased movement rates in response to motorised recreation. Females with cubs did not increase avoidance, however they had the largest response in terms of higher movement rates. In contrast, for all classes, selection for proximity to trail increased when probability of non‐motorised activity was high, and the effect on movement was dampened relative to the motorised response. Synthesis and applications. By combining selection and movement into a unified modelling framework, we show that bears alter selection and movement behaviour in response to trails and recreation, and that such responses are determined by the type of recreational activity. Reduced selection and increased movement in proximity to motorised trails could affect bears’ ability to exploit foraging opportunities in these areas. Future access management actions for grizzly bear recovery should consider frequency and type of linear feature use by humans rather than solely relying on thresholds relating to feature densities.

Predicting total phosphorus levels as indicators for shallow lake management

Total phosphorus (TP) is commonly used to assess water quality in shallow lakes and other surface waters. Shallow lakes require special consideration because they can transition between two alternative stable states: (1) a clear-water state that typically supports abundant submerged vegetation and provides high quality wildlife habitat, and (2) a turbid-water state with frequent algal blooms and poor habitat quality. A shallow lake’s TP level in relation to critical TP tipping points determines whether the lake is in a highly resilient clear state, a highly resilient turbid state, or whether the lake is in a dynamic region where either state is possible. Further, management options differ for highly resilient clear lakes versus lakes that may be in the turbid state. For example, resilient clear lakes may be assigned special watershed and shoreline protection to preserve their healthy conditions. On the other hand, managers may plan to allocate resources for assessment and possible in-lake management for lakes that have TP levels where the turbid state is possible. Managers would benefit from models that can predict whether a lake is in a resilient clear state or may be in the turbid state without physically visiting a lake to collect water samples or other in-lake data.We used TP data from 118 shallow lakes in Minnesota and previously estimated TP tipping points to classify lakes as either highly resilient clear lakes (“stable-clear”) or possibly turbid (“bistable-turbid”). We used random forest methodology to build models for predicting these two TP classes using both remotely sensed watershed-scale predictors and in-lake variables, and we performed recursive feature elimination to find the most parsimonious model. We demonstrate that TP class can be predicted using only watershed-scale remotely sensed variables and that land cover and use, soil texture, and ecoregion are key predictor variables for TP class. We highlight how our model predictions can be used as indicators to help make management decisions for a set of shallow lakes.

Tanglehead in Southern Texas: A Native Grass with an Invasive Behavior

On the Ground • Tanglehead is a native bunchgrass with a pan-tropical distribution. Historically, tanglehead was common but not abundant in southern Texas and was considered a decreaser whose presence indicated good range condition. • Beginning in the late 1990s, the Texas Coastal Sand Plain ecoregion witnessed dramatic increases in the abundance and distribution of tanglehead: thousands of acres of former grasslands were replaced by dense monotypic stands of tanglehead, reducing habitat quality for livestock and wildlife. • Our research has focused on understanding factors related to tanglehead's expansion, its effects on habitat quality, and management practices that can improve range condition and habitat quality.