Capercaillie in Scotland have declined in number and contracted in range since the 1970s, most remaining in Strathspey on the northwest flank of the Cairngorm mountains. Strathspey, however, is popular for recreation and suffers anthropogenic disturbance from visitors and their use of new forest tracks and remote, off-track areas. Disturbance reduces the area of forest available to Capercaillie. Refuge areas wherein the creation of new tracks is not allowed, and in which recreation is not encouraged, are a management option that might mitigate such effects. We simulate this possibility for the area covered by Forest and Land Scotland’s Strathspey Land Management Plan. Spatially explicit, stage-based matrix models assessed the potential of protecting this population with refuges under ‘optimistic’, ‘central’ and ‘pessimistic’ scenarios based on observed demographic data. Fifteen potential refuges comprised less-disturbed areas of forest still used by Capercaillie. We simulated population growth using combinations of 1, 3, 5, 7, 10, 12 and the full complement of 15 refuge areas. An increasing Capercaillie population could be sustained by a network of refuges, but refuges could not arrest a wider population decline due to causes other than disturbance. This suggests that refuges could play a role in mitigating the increasingly damaging effects of disturbance on Capercaillie in the Strathspey LMP but that the birds’ long-term prospects will depend upon improving their performance more widely.
Wolves and other wildlife species that share habitats with humans with minor options for spatial avoidance must either tolerate frequent human encounters, which may be lethal, or allocate their activity to those periods of the day when the risk of encountering humans is smallest and the consequences least severe. This may force wolves in densely human-populated and cultivated landscapes to either become highly nocturnally active or habituate to human stimuli. Based on 6,220 camera trap images of adult wolves from eight territories in Denmark, we analyzed the extent to which diel activity patterns in a wolf population in a highly cultivated landscape with fragmented forests and extensive public access could be explained from diel variation in darkness, human activity, and prey (deer) activity. We found that diel activity correlated with all three factors simultaneously with human activity (negative) having the strongest total as well as partial effect, followed by darkness (positive) and deer activity (positive). Relative to a model that smoothed activity as a function of time of the day, the three factors accounted for 94% of the explainable diel variation in wolf activity. As most of the apparent selection for darkness could be explained by temporal human avoidance, we suggest that nocturnality (proportion of observations registered at night vs. day at equinox) is a useful proxy for investment in temporal human avoidance. In this study, wolf packs were 7.0 (95% CI: 5.0-9.7) times more active at night than at daytime, which makes Danish wolves amongst the most nocturnally active wolves reported so far. This result confirms the initial prediction that wolves with few options for spatial avoidance, invest heavily in temporal human avoidance.
Decades of persecution resulted in the long-term absence of Grey wolves (Canis lupus) from most European countries. However, recent changes in both legislation and public attitudes toward wolves have eased the pressure and, over the last 20 years, wolves have begun rapidly re-establishing territories in their previous Central European habitats. Unfortunately, those habitats are now heavily altered by humans. Understanding the spatial ecology of wolves in such highly modified environments is crucial, given the high potential for conflict and the need to reconcile their return with multiple human concerns. We equipped twelve wolves (from eight packs) in five Central European areas with GPS collars and calculated their monthly home ranges using Autocorrelated Kernel Density Estimation. In addition, we used ESA WorldCover data to assess the mosaic of available habitats within each home range. Home range size for most wolves (84.6%) ranged from 56.4 to 259.7 km2. Our data confirmed the general seasonal pattern for breeding individuals, with smaller apparent home ranges during the reproduction phase and non-breeders showing no specific pattern. Somewhat predictably, our wolves showed a general preference for remote areas, and especially forests. Some animals within military training areas also showed a broader preference for grasslands, which could be influenced by the specific land use of this habitat type and the high availability of prey. Our results provide a comprehensive insight into the ecology of wolves during their re-colonisation of Central Europe. Though wolves are spreading relatively rapidly across Central European landscapes, their permanent reoccupation remains uncertain due to conflicting concerns with the human population. To secure the restoration of European wolf populations, further robust biological data, including data on spatial ecology, will be needed to clearly identify the management implications.
Predators can affect ecosystems through non-consumptive effects on their prey, which can lead to cascading effects on the vegetation. In mammalian communities, such cascading effects on whole ecosystems have mainly been demonstrated in protected areas, but the extent to which such effects may occur in more human-dominated landscapes remains disputable. With the recolonisation of wolves (Canis lupus) in Europe, understanding the potential for such cascading processes becomes crucial for understanding the ecological consequences of wolf recovery and making appropriate management recommendations. Here, we investigate the evidence for non-consumptive effects of wolves on their wild ungulate prey and cascading effects on the vegetation in European landscapes. We reviewed empirical studies reporting wild ungulate responses to wolves involving spatio-temporal behaviour at large and fine spatial scales, activity patterns, vigilance, grouping, physiological effects, and effects on the vegetation. We reveal that non-consumptive effects of wolves in Europe have been studied in few regions and with focus on regions with low human impact and are highly context-dependent and might often be overruled by human-related factors. Further, we highlight the need for a description of human influence in NCE studies. We discuss challenges in NCE research and the potential for advances in future research on NCE of wolves in a human dominated landscape. Further, we emphasise the need for wildlife management to restore ecosystem complexity and processes, to allow non-consumptive predator effects to occur.
Efficient wildlife management requires precise monitoring methods, e.g., to estimate population density, reproductive success, and survival. Here, we compared the efficiency of drone and ground approaches to detect and monitor GPS-collared female moose (Alces alces) and their calves. Moreover, we quantified how drone (n = 42) and ground (n = 41) approaches affected moose behavior and space use (n = 24 individuals). The average time used for drone approaches was 17 minutes compared to 97 minutes for ground approaches, with drone detection rate being higher (95% of adult female moose and 88% of moose calves) compared to ground approaches (78% of adult females and 82% of calves). Drone detection success increased at lower drone altitudes (50-70 m). Adult female moose left the site in 35% of drone approaches (with > 40% of those moose becoming disturbed once the drone hovered < 50 m above ground) compared to 56% of ground approaches. We failed to find short-term effects (3-h after approaches) of drone approaches on moose space use, but moose moved > 4-fold greater distances and used larger areas after ground approaches. Similarly, longer-term (24-h before and after approaches) space use did not differ between drone approaches compared to days without known disturbance, but moose moved comparatively greater distances during days of ground approaches. In conclusion, we could show that drone approaches were highly efficient to detect adult moose and their calves in the boreal forest, being faster and less disturbing than ground approaches, potentially making them a useful tool to monitor and study wildlife.
The loss of wildlife species due to habitat deterioration and pollution represents the major threats to biodiversity conservation. This is compounded by the rapid development of infrastructure i.e., the expansion of roads, railways, harbours; construction of industries, human settlements and agricultural infrastructure. A few studies have explored the significant effects of emerging infrastructure development on wildlife species and habitats particularly in developing countries like Tanzania. We reviewed 58 research articles and reports, to highlight the significant impacts of emerging infrastructure on both aquatic and terrestrial species and habitats in Tanzania. We show that despite the role it plays to the development, the infrastructure contributes significantly to the loss of wildlife species. For instance, avoidance, habitat loss, edge effects incursion, population, isolation, road mortality, and increased human access are among the effects of highway across the Serengeti, Mikumi, and Katavi National parks in Tanzania. Effect of on health of aquatic species, pollution and loss of habitat have been pointed out as impacts due to construction of hotels and industries upstream and along the coasts, expansion of harbours and agricultural activities. Environment effects i.e., reduction of forest, ecosystem services, and riverine habitat, loss of species are anticipated due to the construction of Stiegler’s Gorge Hydroelectric Dam, across the Rufiji River in eastern Tanzania. Though infrastructure development undoubtedly offers opportunities to boost economic growth and reduce poverty in developing nations, it should be planned to have the least possible negative effects on biodiversity. Well–planned infrastructure development could lessen human pressure on wildlife species and habitats. This paper would be useful to policymakers and politicians in developing nations to avoid implementing infrastructure in biodiversity–rich or protected areas as their decision may jeopardize the integrity of wildlife species and future generations.
1. The severe decline of hazel dormice (Muscardinus avellanarius) is well documented and has led to increased legislative protection both in the UK and across Europe. Conservation measures for this species often include provision of nestboxes as a mitigation or enhancement technique after development projects. Previous research has offered some insights into how to select suitable general locations for nestboxes, but where to best place individual boxes to promote occupancy is less well understood. We hypothesised microhabitat variables related to proximity to food sources and nest building material will affect nestbox occupancy by dormice and should be considered when placing individual boxes within a selected site. 2. To assess individual nestbox occupancy by hazel dormice, 76 microhabitat variables were collected from 45 occupied and unused nestboxes in a deciduous woodland in Berkshire,UK. Variables were then used to predict probability of nestbox occupancy (observed from 2017 to 2021) using Random Regression models. 3. Results reveal nestboxes were more likely to be occupied by hazel dormice in sites with higher local cover and abundance of hazel trees (Corylus avellana), greater overall tree abundance but not fully closed canopies (best around 80-85%), more hawthorn (Crataegus monogyna) and honeysuckle (Lolium periclymenum), and when located further from footpaths. 4. Our results build on previous literature on habitat preferences of hazel dormice and importantly provide insight into relevant microhabitat variables that offer recommendations for where to place individual nestboxes to promote occupancy and facilitate recovery of hazel dormice.
Wildlife populations can be unmarked, meaning individuals lack visually distinguishing features for identification; populations may also exhibit non-independent movements, meaning individuals move together. For either unmarked or non-independent individuals, models based on spatial capture-recapture (SCR) approaches estimate abundance, density, and other population parameters critical for monitoring, management, and conservation. However, when individuals are both unmarked and non-independent, few model options exist. One approach has been to apply unmarked models and not address the non-independence despite unquantified impacts of overdispersion on bias, precision, and the ability to make robust ecological inferences. We conducted a simulation study to quantify the impact of non-independence on the performance of spatial count (SC) and spatial partial identity models (SPIM), two SCR-based unmarked modeling approaches, and used the performance of fully marked and independent SCR as a reference. We varied the levels of non-independence (aggregation and cohesion), detection probability, and the number of partial identity covariates used to resolve identities in SPIM estimation. We expected estimates of abundance and sigma (the spatial scale of individual movement) to be increasingly biased and less precise as aggregation and cohesion increased. Results showed that models indeed became less robust to increasing non-independence, especially for abundance, but importantly suggested that only SPIM could be reliably applied under low levels of cohesion when sufficient partial identity covariates are available. SC yielded consistently biased estimates with inflated precision that could not be corrected to nominal levels of coverage. SCR was the most robust across all combinations of aggregation and cohesion, as expected. We therefore advise against the use of SC models for estimating population parameters when individuals are known to be non-independent, caution that SPIM may be used under narrow ecological conditions, and encourage continued investigations into sampling design and methods development for populations of unmarked and non-independent individuals.
The human population is growing rapidly, increasing pressure on natural habitats. Suitable habitats for resident and migratory waterbirds are, therefore, more threatened. This study analyses how the presence of anthropogenic land cover (urban area and cropland) on multiple spatial scales affects the community composition of waterbirds along the Nile in Egypt. We analysed data collected during the international waterbird census, 2017-2018, combined with data from satellite images on land cover at a multi-spatial scale. The census covered 970 km, compromising 194 shoreline transects of 5 km along the River Nile, Egypt. The area includes a broad gradient of human disturbance, making this dataset ideal for assessing effects of anthropogenic land cover on waterbird community composition. We tested whether the waterbird community indices and guild composition were associated with urban area and cropland, and other land covers (e.g., grassland, wetland) at spatial scales of 100, 500, 1,000 and 5,000 m. We recorded over 96,000 waterbirds and show that landscape characteristics at larger spatial scales (5,000 m) explained more of the species and guilds’ presence than smaller scales. Species richness increased with increasing water surface area of the river within the transect and decreased with increasing urban area and cropland. Waders were negatively associated with urban area. Overall, the guilds’ composition was poorly predicted by anthropogenic land cover and other landscape compositions, probably because species within a guild do not react similarly to increasing human disturbance. The probability of observing red-listed species decreased with increasing urban area. With this study, we expand on the existing evidence by showing that species richness negatively correlates with anthropogenic pressure, and we highlight the importance of studying the responses of species rather than guilds. Our study shows the relevance of considering the landscape at larger scales while planning for conservation measures, especially in such human-dominated landscapes.
Reptiles and amphibians have been recognised as being some of the world’s most at-risk species from the impacts of human development. In particular, roads have been identified as having a significant impact on herpetofauna due to roadkill and fragmentation. Despite road mortality affecting herpetofauna greater than other species, the topic of wildlife vehicle collision (WVC) studies, which influence mitigation, is biased towards larger species due to higher human costs from WVCs. In addition to mitigation research, government funding for species protection and recovery has also been found to be highly disproportionate among species groups. This bias has resulted in a lack of research on effectiveness and clear and consistent guidance on mitigation for smaller animals such as reptiles and amphibians. Wildlife fencing is one method of mitigation that has proven to help reduce WVCs and can help maintain connectivity when combined with wildlife crossings. There have been more studies in recent years that have focused on herpetofauna mitigation and these have helped inform best practice guidance. In this article we review current freely available best practice guidance for fencing designed to manage conflict of herpetofauna around transport networks from across the world. We have summarised findings that compare and highlight key factors that include the following: Material type, Fence height, and Fence features. Combining factors from existing guidance, recent research and our practical observations on mitigation projects, we provide a summary of recommendations along with diagrams and descriptions that reflect the analysed guidance. We also identify and highlight any areas that may need further research and investigation to help build upon the status quo and enable us to better utilise fencing as a conflict management tool for herpetofauna.
Wild vertebrates usually avoid ground disturbed by humans but consequences for their distribution and density are uncertain. The local distribution of capercaillie shifted after an increase in disturbance along woodland tracks adjacent to an expanding Scottish village. We surveyed the birds’ droppings before and after the building of 30 new houses, and model the probability of finding droppings (Pf) in relation to period plus two disturbance gradients – distance to a much disturbed ‘entry zone’ by the village (dE) and ‘distance to nearest track’ (dT). Estimates of Pf are benchmarked to average Pf (Pfav) – a notional scenario in which the birds’ distribution is unaffected by tracks. Change between periods occurred mainly on a strip of ground centred on tracks and averaging 80 m wide, where Pf fell from about 0.5 Pfav before the development to 0.2 Pfav after it. By contrast, Pf on ground 120–260 m from tracks, under a third of the 273 ha main study area, remained at about 3 Pfav throughout the study – indicating a net influx of capercaillie displaced from ground beside tracks in both periods. No capercaillie droppings were found in the entry zone. Beyond this zone, throughout the study, Pf increased as tracks sparsened until dE approached 400 m – whereupon track density and Pf steadied together. Beyond 400 m, Pf remained depressed on ground near tracks (dT ⪅ 100 m). New desire paths after the development caused the proportion of ground where dT < 100 m to increase slightly, from 56% to 60%. Birds on roughly half of a 50 ha refuge should be undisturbed by direct effects of track-based activities – but, if increases in density caused by displaced birds are also deemed disturbance, a refuge would need to be over 3 km2 to keep half of it undisturbed.