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 conservation and management of large carnivores is a challenging task for researchers seeking to foster human-wildlife coexistence. Agent-based models (ABMs) allow researchers to design realistic simulations of their study system, including environmental, anthropogenic and ecological agents and their characteristics to examine interactions at landscape scales and investigate how interventions may alter potential outcomes. Including high-resolution Geographic Information Systems (GIS) data and real-world ecological data streams in ABMs represents an innovative approach for site-specific investigations into how best to manage the return of large carnivores. We used GIS-integrated ABMs to study the outcome of wolf reintroduction to Ireland’s national parks with respect to wolf ecology and wolf-livestock interactions. We introduced management strategies and policy interventions to assess how wolf-livestock interactions could be influenced by wildlife managers and whether outcomes were site-specific. Our study found that wolves could persist past the initial introduction in each protected area regardless of which reintroduction strategy is utilised, however, human-wildlife conflict warning signs emerged. Wolves extensively disperse outside protected areas, den-sites are located close (c. 1.5km) to park boundaries and livestock-depredations do occur. Management and policy interventions significantly reduced the likelihood of human-wildlife conflict by reducing the number of livestock depredations and creating ecological buffers that reduce wolf-human interactions, however, the individual characteristics of the protected area determined the success of each management and policy intervention. This analysis reveals nuanced differences in the response of each study area to the same management and policy interventions, demonstrating that the outcome of management and policy interventions is highly dependent on specific ecological conditions captured in GIS data. This underscores the importance of integrating high-resolution GIS data into ecological ABMs and the power that such integration can bring to these models for delivering tailored recommendations to decision-makers enabling human-wildlife coexistence with large carnivores in complex landscapes.
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.
Survival among juvenile ungulates is an important demographic trait affecting population dynamics. In many systems, juvenile ungulates experience mortality from large carnivores, hunter harvest and climate-related factors. These mortality sources often shift in importance both in space and time. While wolves (Canis lupus) predate on moose (Alces alces) throughout all seasons, brown bear (Ursus arctos) predation and human harvest happen primarily during early summer and fall, respectively. Hence, understanding how the mortality of juvenile moose is affected by predation, harvest and climate is crucial to adaptively managing populations and deciding sustainable harvest rates. We used data from 39 female moose in south-central Scandinavia to investigate the mortality of 77 calves in summer/fall and winter/spring, in relation to carnivore presence (defined as wolf presence and bear density), summer productivity, secondary road density, winter severity and migratory strategy (migratory versus resident) using logistic regressions. Summer mortality varied significantly between years but was not correlated to any of our covariates. In winter, calf mortality was higher with deeper snow in areas with wolves compared to areas without and increased more strongly with an increasing proportion of clearcuts/young forests in the presence of wolves compared to when wolves were absent. Lastly, increasing hunting risk was associated with higher calf mortality, and migratory females had higher calf mortality compared to stationary ones. Our study provides useful insight into mortality rates of moose calves coexisting with two large carnivores and with an intensive harvest pressure. Increasing our understanding of the mechanisms driving calf mortality both in summer and winter will become increasingly important if the populations of wolves and bears continue to expand and the moose population declines, and both summers and winters become warmer.
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.
Chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is a major driver of amphibian decline worldwide. The global presence of Bd is driven by a synergy of factors, such as climate, species life history, and amphibian host susceptibility. Here, using a Bayesian data-mining approach, we modelled the epidemiological landscape of Bd to evaluate how the infection varies across several spatial, ecological, and phylogenetic scales. We compiled global information on Bd occurrence, climate, species ranges, and phylogenetic diversity to infer the potential distribution and prevalence of Bd. By calculating the degree of co-distribution between Bd and our set of environmental and biological variables (e.g., climate and species), we identified which factors could potentially be related to Bd presence and prevalence using a geographic correlation metric, epsilon (ε). We fitted five ecological models based on: i) amphibian species identity, ii) phylogenetic species variability values for a given species assemblage, iii) temperature, iv) precipitation, and v) all variables together. Our results extend the findings of previous studies by identifying the epidemiological landscape features of the presence of Bd. This ecological modelling framework allowed us to generate explicit spatial predictions for Bd prevalence at global scale and a ranked list of species with high/low probability of Bd presence. Our geographic model was able to identify areas with high potential for Bd prevalence as potential risk areas and areas with low potential Bd prevalence as potential refuges (free Bd). At the amphibian assemblage level, we found a non-relationship with amphibian phylogenetic signals, but a significantly negative correlation between observed species richness and Bd prevalence indicated a potential dilution effect at the landscape scale. Our model may identify potential susceptible species and areas at risk of Bd presence which could be used to prioritize regions for amphibian conservation efforts and assess species and assemblage risk
Monitoring population dynamics is of fundamental importance in conservation but assessing trends in abundance can be costly, especially in large and rough areas. Obtaining trend estimations from counts performed in only a portion of the total area (sample counts) can be a cost-effective method to improve the monitoring and conservation of species difficult to count. We tested the effectiveness of sample counts in monitoring population trends of wild animals, using as a model population the Alpine ibex (Capra ibex) in Gran Paradiso National Park (Italy), both with computer simulations and using historical census data collected over the last 65 years. Despite sample counts could fail to correctly estimate the true population abundance, sampling half of the target area could reliably monitor the trend of the target population. In case of strong changes in abundance, an even lower proportion of the total area could be sufficient to identify the direction of the population trend. However, when there is a high yearly trend variability, the required number of samples increases and even counting in the entire area can be ineffective to monitor population dynamics. Lastly, the effect of other parameters (such as which portion of the area is sampled or the detectability) was marginal, but these should be tested case by case. Sample counts could therefore constitute a viable alternative to assess population trends, allowing for important, cost-effective improvements in the monitoring of wild animals of conservation interest.
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.
The urea nitrogen salvaging process (UNS) supports the symbiotic relationship between ruminants and their gastrointestinal microbiome by both supplying nitrogen and buffering bacterially-derived short chain fatty acids (SCFAs). Studying such physiological processes via investigation of rumen papillae morphology and functioning, as well as western blotting to detect rumen urea transporters, allows researchers to test hypotheses linking physiology and ecology. The goal of this innovative approach is to indicate the way forward for future research. Our previous studies have shown the importance of the UT-B2 urea transporters in the rumen of wild fallow deer living in Phoenix Park, Dublin. In this current pilot study, we investigated the effects on these transporters of seasonal changes – linked to changes in feeding intake during and after the mating season - and acceptance of artificial food from park visitors in adult male bucks. Investigation of the rumen papillae revealed that animals culled in January had significantly longer papillae than those culled just after the rutting season in November, when bucks interrupted feeding from a few days to weeks. In contrast, western blotting analysis showed that there was no significant difference in the abundance of UT-B2 transporters between these two groups. Adult males that had displayed consistent begging behaviour to obtain food from human visitors to the park had a higher papillae density. Furthermore, these animals had a significantly higher abundance of UT-B2 transporters, which was shown by immunolocalization studies to be predominantly in the stratum basale layer of the rumen papillae. Our research suggests that human-wildlife feeding interactions can have subtle effects on the physiology of individual animals involved. The findings of this novel study therefore improve our understanding of basic rumen physiological processes, but also add insight into the unseen effects that humans feeding wildlife may have.
The civil war in Côte d’Ivoire between 2002 and 2010 led to a hike in human disturbances and the disappearance of African lions (Panthera leo) from the Comoé National Park (CNP). After the crisis, many efforts to conserve and restore this ecosystem and its biodiversity have been made and the management authority is considering the reintroduction of lions. We assessed the acceptance of the reintroduction of the lions by the local populations; through a sociological survey, we administered questionnaires to 307 people in 23 villages bordering CNP. A large majority (71%, n=218) were in favor of the return of the lions, with significant variation among ethnic groups. A general linear model analysis (GLM) revealed that apart from ethnic group, profession and origin (village) are significantly determinant for the acceptance of lion reintroduction to CNP. Most respondents had knowledge of the species (96%, n=296). The majority of respondents (81%, n=250) acknowledged having coexisted with lions, with previous conflicts with lions reported by 16% (n = 49) of respondents and a willingness to coexist with future lions reported by 81% (n = 248) of respondents. More than 84% (n=260) of respondents believed that there would be benefits associated with lion return to CNP and 52% (n=161) and 14% (n=44) of respondents believed that the potential benefits would be greater and less than the possible risks associated with lion return. Just under half of respondents (42%; n=129) confirmed the current participatory management of CNP while the majority (91%; n=280) confirmed the possibility of taking own precautions to prevent attacks from future lion. We recommend the improvement of the involvement of indigenous communities in any reintroduction and the implementation of environmental education projects as a condition for the potential reintroduction of lions.