Migration conveys many benefits to species, ecosystems, and people but relies upon connected landscapes. Anthropogenic development can present barriers for migrants, but many barriers are semi-permeable, allowing unhindered or delayed passage. We used a modified version of the Barrier Behavior Analysis (BaBA) to investigate seasonal movement responses to five roads in northwestern Alaska by adult female Western Arctic Herd caribou (Rangifer tarandus) from 2009 to 2024. Our analyses revealed some altered movement in response to all focal roads. We found that the roads were semi-permeable barriers to movement, with altered behaviors including bouncing away, moving back-and-forth, and tracing along roads. Overall, 63.1% of collared animals encountered (entered a road-specific buffer) at least one focal road. Of these, 61.5% displayed altered movements. At the scale of individual encounters with roads, we found altered movement in 27.1% of road encounters. Most encounters occurred during fall migration and caribou with altered behavior spent an average of 9.4 days longer near focal roads than those with unaltered movement. Altered movements were balanced among the behavioral responses. Most altered movements occurred near the Red Dog mining road (60.3%) or during fall migration (51.9%) but lasted longest during winter (17.2 days on average). We confirm prior findings of altered fall movements near the Red Dog road and demonstrate that movement behavior is also altered around other roads and in other seasons. Nonetheless, many collared caribou did not display altered movements in response to roads, emphasizing the need for further research to understand the mechanistic drivers of caribou movement responses. Given increasing pressures for infrastructure development and global challenges facing migratory species, it is critical to identify mitigation measures and inform management decisions seeking to balance responsible development with conservation of natural systems, including migratory species and the people that rely upon them.

Barriers can affect the movement, migratory patterns, and demographic rates of ungulates. Even in highly remote areas with relatively little development, like northwest Alaska, isolated roads can alter the movements of ungulates such as caribou (Rangifer tarandus). Here, a solitary, 80-km long industrial road connecting a large zinc and lead mine to a port affects caribou migrations. Using location and survival data from 366 GPS collared, adult female caribou representing > 850 caribou-years from 2010 to 2023, we assessed whether caribou whose fall movements were altered by the road experienced higher mortality risk compared to those whose movements were unaltered. Of the 101 caribou-years that came within 20 km of the road, 58% displayed altered movements. The survival rate of caribou whose movements were unaltered by the road was 20% higher than those caribou whose movements were altered by it, though difference was not significant (p > 0.05). Increased movements, delayed migration, and/or changes in habitat selection related to altered movements could still have energetic and demographic consequences. Caribou that crossed or circumvented the road had significantly higher survival rates (78.5% survived until calving) than caribou that did not cross or circumvent the road (i.e., it acted as an impermeable barrier and the caribou wintered north of it; 57.9%). Given our results, we posit that enhancing the permeability of roads could improve the survival of caribou in the region.

As camera trapping has become a standard practice in wildlife ecology, developing techniques to extract additional information from images will increase the utility of generated data. Despite rapid advancements in camera trapping practices, methods for estimating animal size or distance from the camera using captured images have not been standardized. Deriving animal sizes directly from images creates opportunities to collect wildlife metrics such as growth rates or changes in body condition. Distances to animals may be used to quantify important aspects of sampling design such as the effective area sampled or distribution of animals in the camera's field‐of‐view. We present a method of using pixel measurements in an image to estimate animal size or distance from the camera using a conceptual model in photogrammetry known as the ‘pinhole camera model’. We evaluated the performance of this approach both using stationary three‐dimensional animal targets and in a field setting using live captive reindeer Rangifer tarandus ranging in size and distance from the camera. We found total mean relative error of estimated animal sizes or distances from the cameras in our simulation was −3.0% and 3.3% and in our field setting was −8.6% and 10.5%, respectively. In our simulation, mean relative error of size or distance estimates were not statistically different between image settings within camera models, between camera models or between the measured dimension used in calculations. We provide recommendations for applying the pinhole camera model in a wildlife camera trapping context. Our approach of using the pinhole camera model to estimate animal size or distance from the camera produced robust estimates using a single image while remaining easy to implement and generalizable to different camera trap models and installations, thus enhancing its utility for a variety of camera trap applications and expanding opportunities to use camera trap images in novel ways.

Many animals migrate to take advantage of temporal and spatial variability in resources. These benefits are offset with costs like increased energetic expenditure and travel through unfamiliar areas. Differences in the cost-benefit ratio for individuals may lead to partial migration with one portion of a population migrating while another does not. We investigated migration dynamics and winter site fidelity for a long-distance partial migrant, barren ground caribou (Rangifer tarandus granti) of the Teshekpuk Caribou Herd in northern Alaska. We used GPS telemetry for 76 female caribou over 164 annual movement trajectories to identify timing and location of migration and winter use, proportion of migrants, and fidelity to different herd wintering areas. We found within-individual variation in movement behavior and wintering area use by the Teshekpuk Caribou Herd, adding caribou to the growing list of ungulates that can exhibit migratory plasticity. Using a first passage time-net squared displacement approach, we classified 78.7% of annual movement paths as migration, 11.6% as residency, and 9.8% as another strategy. Timing and distance of migration varied by season and wintering area. Duration of migration was longer for fall migration than for spring, which may relate to the latter featuring more directed movement. Caribou utilized four wintering areas, with multiple areas used each year. This variation occurred not just among different individuals, but state sequence analyses indicated low fidelity of individuals to wintering areas among years. Variability in movement behavior can have fitness consequences. As caribou face the pressures of a rapidly warming Arctic and ongoing human development and activities, further research is needed to investigate what factors influence this diversity of behaviors in Alaska and across the circumpolar Arctic.

Abstract Wildlife management often involves trade‐offs between protecting species and allowing human activities and development. Ideally, these decisions are guided by scientific studies that quantify the impacts of proposed actions on the environment. However, critical information to assess impacts of proposed activities may be lacking, such as certainty in where actions will take place, which may hinder a robust impact assessment. To address this issue, we present the Development Impacts Analysis (DIA), which employs Monte Carlo simulation modeling to quantify the environmental consequences of proposed development scenarios, while accounting for uncertainty in the exact location of future development. We applied the DIA to five proposed oil leasing management scenarios under a revised management plan for the National Petroleum Reserve—Alaska. For each management scenario with differing levels of proposed development (“alternatives”), oil production pads and roads were randomly simulated in proportion to estimated undiscovered oil and following alternative‐specific restrictions. We assessed habitat displacement for two caribou (Rangifer tarandus) herds, eight shorebird species, and black brant (Branta bernicla) based on reported responses to development, repeating the process 100 times for each alternative. Some habitat loss was reported for each proposed alternative, but the amount of impact varied by alternative and species. One caribou herd and most bird species indicated greatest effects in the alternative with the least restrictions on development and lesser impacts under more protective alternatives. Our results emphasized the importance of considering spatial variation in development effects and species‐specific differences when evaluating management proposals. The DIA quantified potential impacts on a suite of species under proposed management alternatives, while accounting for uncertainty in where development will occur and providing confidence intervals on estimated impacts. This illustrates that uncertainty need not preclude management decisions about establishment of broad land use restrictions prior to submission of project‐level proposals but can instead be explicitly incorporated into decision making. While no single management approach will likely benefit all species, use of tools such as the DIA allows managers to quantify trade‐offs among species and pursue approaches that balance the needs of various taxa and other management objectives.

Ecologists are dedicated to expanding our understanding of complex, interconnected species and sys-tems. We learn many different skills and strategies for research, teaching, and communication through formal and informal training and professional development. However, more often than we care to admit, the numerous people and struggles behind the science are glossed over in favor of focusing on a few individuals and flashy scientific results. There are many early career scientists moving ecological knowl-edge forward, collecting one more data point, teaching themselves how to analyze results, learning project management on the job, and striving to improve their scientific writing. These efforts are not always recognized or supported, and ecologists, particularly at the beginning of their careers, may not get all of the resources they need to be successful. We, the officers in the Early Career Ecologists (ECE) section, feel strongly about promoting professional development and mentoring skills. As each of us became more involved with the Ecological Society of America (ESA), we gravitated toward the ECE section, which is dedicated to providing support for those of us just starting on our professional journeys.

Migration is common worldwide as species access spatiotemporally varying resources and avoid predators and parasites. However, long-distance migrations are increasingly imperiled due to development and habitat fragmentation. Improved understanding of migratory behavior has implications for conservation and management of migratory species, allowing identification and protection of seasonal ranges and migration corridors. We present a technique that applies circuit theory to predict future effects of development by analyzing season-specific resistance to movement from anthropogenic and natural environmental features across an entire migratory path. We demonstrate the utility of our approach by examining potential effects of a proposed road system on barren ground caribou (Rangifer tarandus granti) and subsistence hunters in northern Alaska. Resource selection functions revealed migratory selection by caribou. We tested five scenarios relating habitat selection to landscape resistance using Circuitscape and GPS telemetry data. To examine the effect of potential roads on connectivity of migrating animals and human hunters, we compared current flow values near communities in the presence of proposed roads. Caribou avoided dense vegetation, rugged terrain, major rivers, and existing roads in both spring and fall. A negative linear relationship between resource selection and landscape resistance was strongly supported for fall migration while spring migration featured a negative logarithmic relationship. Overall patterns of caribou connectivity remained similar in the presence of proposed roads, though reduced current flow was predicted for communities near the center of current migration areas. Such data can inform decisions to allow or disallow projects or to select among alternative development proposals and mitigation measures, though consideration of cumulative effects of development is needed. Our approach is flexible and can easily be adapted to other species, locations and development scenarios to expand understanding of movement behavior and to evaluate proposed developments. Such information is vital to inform policy decisions that balance new development, resource user needs, and preservation of ecosystem function.

Animals and humans regularly make trade-offs between competing objectives. In Addo Elephant National Park (AENP), elephants (Loxodonta africana) trade off selection of resources, while managers balance tourist desires with conservation of elephants and rare plants. Elephant resource selection has been examined in seasonal savannas, but is understudied in aseasonal systems like AENP. Understanding elephant selection may suggest ways to minimise management trade-offs. We evaluated how elephants select vegetation productivity, distance to water, slope and terrain ruggedness across time in AENP and used this information to suggest management strategies that balance the needs of tourists and biodiversity. Resource selection functions with time-interacted covariates were developed for female elephants, using three data sets of daily movement to capture circadian and annual patterns of resource use. Results were predicted in areas of AENP currently unavailable to elephants to explore potential effects of future elephant access. Elephants displayed dynamic resource selection at daily and annual scales to meet competing requirements for resources. In summer, selection patterns generally conformed to those seen in savannas, but these relationships became weaker or reversed in winter. At daily scales, resource selection in the morning differed from that of midday and afternoon, likely reflecting trade-offs between acquiring sufficient forage and water. Dynamic selection strategies exist even in an aseasonal system, with both daily and annual patterns. This reinforces the importance of considering changing resource availability and trade-offs in studies of animal selection.Conservation implications: Guiding tourism based on knowledge of elephant habitat selection may improve viewing success without requiring increased elephant numbers. If AENP managers expand elephant habitat to reduce density, our model predicts where elephant use may concentrate and where botanical reserves may be needed to protect rare plants from elephant impacts.

Current systems of conservation reserves may be insufficient to sustain biodiversity in the face of climate change and habitat losses. Consequently, calls have been made to protect Earth's remaining wildlands and complete the system of protected areas by establishing conservation reserves that (1) better represent ecosystems, (2) increase connectivity to facilitate biota movement in response to stressors including climate change, and (3) promote species persistence within intact landscapes. Using geospatial data, we conducted an assessment for expanding protected areas within the contiguous United States to include the least human-modified wildlands, establish a connected network, and better represent ecosystem diversity and hotspots of biodiversity. Our composite map highlights areas of high value to achieve these goals in the western United States, where existing protected areas and lands with high ecological integrity are concentrated. We also identified important areas in the East rich in species and containing ecosystems that are poorly represented in the existing protected area system. Expanding protection to these priority areas is ultimately expected to create a more resilient system for protecting the nation's biological heritage. This expectation should be subject to rigorous testing prior to implementation, and regional monitoring will ensure areas and actions are adjusted over time.

Background: Ungulate movements are influenced by a variety of biotic and abiotic factors, which may affect connectivity between key resource areas and seasonal ranges. In northwestern Alaska, one important question regarding human impacts on ungulate movement involves caribou ( Rangifer tarandus) response to autumn hunting and related aircraft activity. While concerns have been voiced by local hunters about the influence of transporter aircraft and nonlocal sport hunters, there has been little quantitative analysis of the effects of hunter activity on caribou movement. We utilized a novel spatial dataset of commercial aircraft landing locations and sport hunter camps in and around Noatak National Preserve to analyze resource selection of caribou in autumn for non-local hunting activity and environmental features. We combined step selection functions with randomized shortest paths to investigate whether terrain ruggedness, river width, land cover, and hunting activity ( in the form of aircraft landings and sport hunter camps) facilitated or impeded caribou movement. By varying a parameter in the randomized shortest path models, we also explored the tradeoff between exploration and exploitation in movement behavior exhibited by traveling caribou.Results: We found that caribou avoided rugged terrain and areas with more river, forest, and tall shrubs while selecting for areas dominated by tussock tundra and dwarf shrubs. Migration of caribou through Noatak does not appear to be inhibited by sport hunting activity, though this does not preclude the possibility of temporary effects altering availability of caribou for individual hunters. Caribou exhibited exploratory movement, following predictions of a random walk model. This behavior may facilitate the location of remaining patches of high-quality forage prior to the onset of winter, especially during mild autumns.Conclusions: Understanding animal movement behavior is fundamental to protecting critical areas of connectivity and to informing management decisions. Our study identifies migratory connectivity and hotspots of potential conflict among user groups, enabling development of policies that balance human access with species conservation.

Wildlife managers use a variety of interventions to alter species distributions but it is uncertain how effective these techniques will be under shifting climate. There is growing recognition of the importance of including climate change scenarios into management planning and actions, but this is lacking in many systems. The spatially-explicit ecosystem model, SAVANNA, was used to predict shifts in large herbivore distribution from 2020 to 2079 under scenarios of climate change, water management, and elephant population growth in Kruger National Park, South Africa. Directional persistence was used to indicate where five large herbivore species elephant (Loxodonta africana), buffalo (Syncerus coffer), impala (Aepyceros melampus), wildebeest (Connochaetes taurinus), and zebra (Equus quagga) were predicted to increase or decrease their density relative to historic conditions. The overlap in herbivore distributions both within and between species was measured to indicate which change agents were likely to influence future distributions as well as when those influences are expected to occur. We found that patterns differed across climate scenarios. Altering artificial water availability had a mixed overall effect on the persistence of herbivore densities across the park, but strongly influenced the overlap in both within- and between species distributions. Elephant numbers generally only had an influence under the most extreme case of population growth. While management actions at the scale of large protected areas or regions may not be able to directly alter climate outcomes, they have the potential to mitigate other stressors, increasing the opportunity for species and ecosystems to adapt to uncertain climate effects. Simulation studies of future conditions under interacting climate and management, such as presented here, have important potential to inform decision making, but do not remove the need for continued monitoring and adaptive management. (C) 2017 Elsevier B.V. All rights reserved.

Within southern Africa's savanna ecosystems, woody and herbaceous species have differing growth characteristics that allow a tenuous co-existance. The high dependence of humans on the landscape, through agricultural production, tourism, and natural resource extraction makes understanding savanna vegetation dynamics essential. Studies analyzing resilience of savannas suggest potential state changes in vegetation structure from continuous grasslands with sporadic woody cover to less biologically productive landscapes. One of the biggest questions in this landscape is the impact of climate change. The spatially explicit SAVANNA model is used to analyze the impact of climate change on vegetation cover across Kruger National Park's (KNP) main land system classifications (Satara, Skukuza, Letaba, and Phalaborwa). Manipulating climate inputs and management regimes allowed us to analyze the resilience of savanna vegetation under multiple Intergovernmental Panel on Climate Change (IPCC) scenarios. Trends in future climate indicate an increase in temperatures greater than 1.0 degrees Celsius and a slight decrease in precipitation by 2080. Model results indicate a long-term decrease in multiple size classes of vegetation across all the four land systems. However, the model runs show differing response to climate change between the woody and herbaceous cover types. Spatial trends across the park follow closely with the north-south climate gradient. The most spatially distinct land system was Skukuza, which exhibited some of the highest initial net primary production (NPP) values and also the greatest decreases in NPP into the future. While this region is projected to lose large proportions of its herbaceous and shrub vegetation it is projected to increase in tree green leaf, mostly related to increasing fine leaf vegetation (Acacia sp.). The northern land systems were already dominated by mopane, but under all model scenarios mopane will increase in Letaba and Phalaborwa. This mopane increase will offset the loss of herbaceous and shrub vegetation, resulting in little to no decrease in NPP across time for these land systems. This work illustrates that landscape resilience is not only impacted by the severity of changing climate but the degree to which we manage such systems. (C) 2016 Elsevier B.V. All rights reserved.

Northern Botswana is influenced by various socio-ecological drivers of landscape change. The African elephant (Loxodonta africana) is one of the leading sources of landscape shifts in this region. Developing the ability to assess elephant impacts on savanna vegetation is important to promote effective management strategies. The Moving Standard Deviation Index (MSDI) applies a standard deviation calculation to remote sensing imagery to assess degradation of vegetation. Used previously for assessing impacts of livestock on rangelands, we evaluate the ability of the MSDI to detect elephant-modified vegetation along the Chobe riverfront in Botswana, a heavily elephant-impacted landscape. At broad scales, MSDI values are positively related to elephant utilization. At finer scales, using data from 257 sites along the riverfront, MSDI values show a consistent negative relationship with intensity of elephant utilization. We suggest that these differences are due to varying effects of elephants across scales. Elephant utilization of vegetation may increase heterogeneity across the landscape, but decrease it within heavily used patches, resulting in the observed MSDI pattern of divergent trends at different scales. While significant, the low explanatory power of the relationship between the MSDI and elephant utilization suggests the MSDI may have limited use for regional monitoring of elephant impacts.

African elephant distribution and impacts are influenced by water availability. This study investigates the formation of piospheres gradients of vegetation degradation with increasing proximity to water at local and landscape scales in Chobe National Park, Botswana. Thirty-four plots record elephant impact on trees in a transect extending over 60km from the Chobe River, differentiating between debarking and browsing on branches. Elephant utilization exhibits local patterns nested within a landscape-level context. At a local scale, branch herbivory decreases with distance from water, while debarking first decreases and then increases again. At a landscape scale, regression and canonical correlation analyses show decreasing debarking with distance from the river. Surprisingly, branch herbivory increases with distance from river, except within the first 10km where previous studies have focused. Elephant impact on vegetation is both more complex and extensive than previously assumed. Piosphere predictions are upheld at the local scale, with utilization decreasing with distance from water. This does not hold at the landscape scale, however, likely due to seasonal shifts in elephant distribution, diet and the presence of water in ephemeral pans. These findings have important implications for elephant management and emphasize the importance of looking across scales when assessing elephant impact.

The rise of user-generated Internet content (i.e. ‘Web 2.0’) has resulted in dramatic changes in the way that scientific information is collected and disseminated. One notable example is Wikipedia (http://www.wikipedia.org), the user-written online encyclopedia with millions of users worldwide. In the 7 years since its inception it has become a staple of the academic community, increasingly used by faculty and students to develop lectures and study aids, research topics for papers and as a source of background information while studying or conducting research.