Death comes for us all: relating movement-integrated habitat selection and social behavior to human-associated and disease-related mortality among gray wolves

Avoiding death affects biological processes, including behavior. Habitat selection, movement, and sociality are highly flexible behaviors that influence the mortality risks and subsequent fitness of individuals. In the Anthropocene, animals are experiencing increased risks from direct human causes and increased spread of infectious diseases. Using integrated step selection analysis, we tested how the habitat selection, movement, and social behaviors of gray wolves vary in the two months prior to death due to humans (being shot or trapped) or canine distemper virus (CDV). We further tested how those behaviors vary as a prelude to death. We studied populations of wolves that occurred under two different management schemes: a national park managed for conservation and a provincially managed multi-use area. Behaviors that changed prior to death were strongly related to how an animal eventually died. Wolves killed by humans moved slower than wolves that survived and selected to be nearer roads closer in time to their death. Wolves that died due to CDV moved progressively slower as they neared death and reduced their avoidance of wet habitats. All animals, regardless of dying or living, maintained selection to be near packmates across time, which seemingly contributed to disease dynamics in the packs infected with CDV. There were no noticeable differences in behavior between the two management areas. Overall, habitat selection, movement, and sociality interact to put individuals and groups at greater risks, influencing their cause-specific mortality.

Animals evoking fear in the Cradle of Humankind: snakes, scorpions, and large carnivores

Theories explain the presence of fears and specific phobias elicited by animals in contemporary WEIRD (Western, educated, industrialized, rich, and democratic) populations by their evolutionary past in Africa. Nevertheless, empirical data about fears of animals in the Cradle of Humankind are still fragmentary. To fill this gap, we examined which local animals are perceived as the most frightening by Somali people, who inhabit a markedly similar environment and the region where humans have evolved. We asked 236 raters to rank 42 stimuli according to their elicited fear. The stimuli were standardized pictures of species representing the local fauna. The results showed that the most frightening animals were snakes, scorpions, the centipede, and large carnivores (cheetahs and hyenas). These were followed up by lizards and spiders. Unlike in Europe, spiders represent less salient stimuli than scorpions for Somali respondents in this study. This conforms to the hypothesis suggesting that fear of spiders was extended or redirected from other chelicerates.

Revealing influencing factors on global waste distribution via deep-learning based dumpsite detection from satellite imagery

With the advancement of global civilisation, monitoring and managing dumpsites have become essential parts of environmental governance in various countries. Dumpsite locations are difficult to obtain in a timely manner by local government agencies and environmental groups. The World Bank shows that governments need to spend massive labour and economic costs to collect illegal dumpsites to implement management. Here we show that applying novel deep convolutional networks to high-resolution satellite images can provide an effective, efficient, and low-cost method to detect dumpsites. In sampled areas of 28 cities around the world, our model detects nearly 1000 dumpsites that appeared around 2021. This approach reduces the investigation time by more than 96.8% compared with the manual method. With this novel and powerful methodology, it is now capable of analysing the relationship between dumpsites and various social attributes on a global scale, temporally and spatially.

Urbanity as a source of genotoxicity in the synanthropic Kelp Gull (Larus dominicanus)

Increases in human population lead to an increase in urban wastes, which could affect wildlife in several ways. Urban pollutants can affect erythrocytes of birds generating morphological membrane and nuclear anomalies. The Kelp Gull (Larus dominicanus) is an opportunistic species, which take advantage of urban environments, thus being highly exposed to environmental pollution. In northeastern Patagonia, the dynamic of the waste management was transformed in the last decade and consequently, gulls changed their movements in response to changes in waste management systems. The food available to the seagulls went from being a mixture of urban/fishing discards until 2015, when this landfill closures, to being domestic urban offerings. In order of evaluating genotoxicity and changes in pollutants exposition due to these changes, we analyzed the frequencies of erythrocytes nuclear abnormalities and micronuclei (ENAs and MN respectively) in 58 blood smears from adults extracted during the non-breeding season in two periods in landfills with different waste compositions: a mixed landfill (ML) in 2013 before closure (n = 24) versus an urban landfill (UL) (n = 34) in 2021. We found that the Kelp Gull showed high values of abnormalities with an average of 151.5 /10,000 RBC in comparison with other seabird species. The bud and notched types of ENAs were the most prevalent abnormalities in both sites. We did not find significate differences in the overall abnormality frequency between sites, however we found significant higher frequencies in displaced and tailed types of ENAs in ML. We also found poikilocytosis, as seen previously in other animals exposed experimentally to pollutants such as metals and crude oil. Cellular abnormalities found in the Kelp Gull suggest an exposition of individuals to pollutants in foraging areas. The hemispheric distribution and the synanthropic characteristics of the species denote its importance as a suitable global monitor of genotoxicity.

Quantifying intra- and inter-species contact rates at supplemental feeding sites in Ethiopia to inform rabies maintenance potential of multiple host species

Rabies, a multi-host pathogen responsible for the loss of roughly 59,000 human lives each year worldwide, continues to impose a significant burden of disease despite control efforts, especially in Ethiopia. However, how species other than dogs contribute to rabies transmission throughout Ethiopia remains largely unknown. In this study, we quantified interactions among wildlife species in Ethiopia with the greatest potential for contributing to rabies maintenance. We observed wildlife at supplemental scavenging sites across multiple landscape types and quantified transmission potential. More specifically, we used camera trap data to quantify species abundance, species distribution, and intra- and inter-species contacts per trapping night over time and by location. We derived a mathematical expression for the basic reproductive number (R₀ ) based on within- and between-species contract rates by applying the next generation method to the susceptible, exposed, infectious, removed model. We calculated R₀ for transmission within each species and between each pair of species using camera trap data in order to identify pairwise interactions that contributed the most to transmission in an ecological community. We estimated which species, or species pairs, could maintain transmission ( R 0 > 1 ${R_0} &gt; 1$ ) and which species, or species pairs, had contact rates too low for maintenance ( R 0 < 1 ${R_0} &lt; 1$ ). Our results identified multiple urban carnivores as candidate species for rabies maintenance throughout Ethiopia, with hyenas exhibiting the greatest risk for rabies maintenance through intra-species transmission. Hyenas and cats had the greatest risk for rabies maintenance through inter-species transmission. Urban and peri-urban sites posed the greatest risk for rabies transmission. The night-time hours presented the greatest risk for a contact event that could result in rabies transmission. Overall, both intra- and inter-species contacts posed risk for rabies maintenance. Our results can be used to target future studies and inform population management decisions.

Conservation status of the world’s carnivorous mammals (order Carnivora)

The conservation of carnivores (order Carnivora) can lead to the conservation of other species as well as entire ecosystems since they play an important ecosystemic role. However, their predatory behaviour has caused many of these species to experience marked population declines worldwide and they may therefore face greater anthropogenic threats than other animal groups. To examine the conservation status, population trends, distribution patterns, habitats and threats of all extant species belonging to this order (N = 290), we collected data from the International Union for the Conservation of Nature's Red List. In addition, we calculated the Red List Index (RLI) to measure the change in extinction risk of species over time. Carnivores are more threatened than mammals in general (26.9% of endangered species vs. 22.7%) and have a significantly higher proportion of species with declining populations (48.3% vs. 31.9%). Eupleridae, Ursidae and Felidae families have the worst conservation status. Between the 1990s and 2000s, most families suffered a considerable decline in their RLI value, the most notable being Felidae. The greatest numbers of threatened carnivore species are found in forest, shrubland and grassland habitats. East and South Asia hold great numbers of carnivore species as well as the highest proportion of threatened and declining species. Hunting and trapping of terrestrial animals, along with habitat loss (caused by deforestation and agricultural expansion), pose the main threats to the Carnivora order. Our findings indicate that, within mammals, the conservation of carnivores should be a priority, and conservation measures directed at this group should be undertaken or increased as a matter of urgency.

High striped hyena density suggests coexistence with humans in an agricultural landscape, Rajasthan

Understanding the mechanism of coexistence, where carnivores adapt to humans and vice versa in the shared landscape, is a key determinant of long-term carnivore conservation but is yet to be comprehensively examined. We explored the coexistence mechanism of striped hyena (Hyaena hyaena) and humans in the shared landscape of Sawai Mansingh Wildlife Sanctuary (SMS WLS), Rajasthan, from November 2019 to March 2021. We used data derived from motion sensors-based surveys, satellite remote sensing images, and household questionnaires to understand socio-ecological, environmental and anthropogenic factors facilitating hyena persistence in the shared landscape. The high density (12 individuals/100 km²) striped hyena in the landscape revealed the coexistence with humans. Being scavengers, they get subsidised food sources and are perceived as low-risk species by humans. Striped hyena minimised temporal activity during the daytime when human activity peaked. However, the highest activity overlap was observed in the agricultural area (Δ1 = 0.39), and likely depicts the high activity due to agricultural practices. While the human settlement was positively associated with the detection of hyenas, the probability of striped hyena captures increased with decreasing distance from human settlement, possibly influenced by high carcass availability, providing the easiest food resources to striped hyena, and allowing them to coexist with humans. This study demonstrates the coexistence of hyenas and humans in the shared landscape supported by mutual benefits, where hyenas benefit from anthropogenic food from scavenging, while humans benefit from waste removal and the non-lethal nature hyenas.

Identifying forensically relevant urban scavengers in Johannesburg, South Africa

Unidentified human remains are frequently recovered in urban environments in South Africa, which undergo forensic (medico-legal) investigations. These remains often exhibit animal scavenging modifications and are frequently scattered by animals. This impacts the collection and forensic analysis of the remains. This study aimed to identify scavenging animals present in two urban environments in Johannesburg, South Africa, and describe their scavenging and scattering behaviours. Six pig carcasses (Sus scrofa domesticus) (30-80 kg) were placed in a veldt in Johannesburg and in an abandoned building complex. Motion-activated cameras recorded the scavenging activities. Scavenger species were identified and their behaviours, scattering pattern, and scavenging bone modifications were described. Slender mongooses (Galerella sanguinea) were the most prolific veldt scavengers. They scattered remains to a maximum distance of 10.5 m in two directions: north and southeast. These mongooses scavenged during the advanced and dry decomposition stages. Gnawing on the angle of the mandible - with multiple parallel scores on the flat surfaces and the angle margin having a stepped appearance - may be a distinguishing scavenging modification feature of the slender mongoose. Hadeda ibis (Bostrychia hagedash) were the only scavengers recorded scavenging on the intestines of a pig carcass in the abandoned building complex. They favoured colonizing insects and created multiple, large holes in the skin and removed the lips to access the insects. The described scavenging behaviours will assist in the reconstruction of postmortem events in forensic cases and the location and collection of scattered remains in Southern Africa.

Growing Up Urban: Hyena Foraging Groups and Social Structure at a City Waste Dump

Urban spotted hyenas (Crocuta crocuta) in Ethiopia are a prime example of large carnivores coexisting with little to no conflict with people in a human-dominated landscape, providing a valuable waste-removal service. To gain insight in how this urban lifestyle persists across generations, we studied hyena group composition at the city waste dump of Mekelle, a regional capital in northern Ethiopia. We found that hyena cubs and sub-adults foraged with adults in groups of highly variable composition. Young urban hyenas already take part in a fission-fusion dynamic that is also characteristic of hyenas in non-urban environments. They do not seem to learn from only one or few close reference adults. Social network analysis revealed no clusters among these dump-visiting hyenas. The number of counted hyenas is furthermore larger than any hyena clan in non-urban areas. All individuals were more or less equally connected to each other, and each hyena had a few connections, but to different individuals. All cubs and sub-adults were connected to each other, over a maximum of four links. Hyenas shared the abundance of food at the waste dump without overt aggression. A much larger number of urban hyenas shares this waste dump at night than would fit into a single forest fragment, such as those associated with orthodox churches where small groups of hyenas have often been observed to rest at daytime. Hyenas appear to commute from different dens and resting sites located around the city, but we have no information on their behavior and group composition away from the dump. We observed no defense of any part of the dump area by any of the foraging groups. In absence of territorial behavior at this city site, the clan concept does not seem to apply to these urban hyenas. Similar to what has been observed in other urban carnivores, individuals at the waste dump behaved as members of conflict-free foraging groups ostensibly sharing food without aggression. Perhaps this is what most strikingly defines their urbanity.

Leopards in the City: The Tale of Sanjay Gandhi National Park and Tungareshwar Wildlife Sanctuary, Two Protected Areas in and Adjacent to Mumbai, India

Recent studies in the last decade have recorded obligate carnivores adapting to human dominated landscapes. Leopards, amongst other large carnivores, are highly adaptable and survive in a range of environments from the arid regions of Africa and the Middle East to the cold regions of the Russian Far East. They are also highly adaptable in their diet and consequently are present close to and even within high-density human landscapes. These also include the edges of urban areas such as Nairobi and Mumbai. Our study, to better understand the coexistence of leopards and humans, was conducted in 104 km2 of Sanjay Gandhi National Park (SGNP), which is surrounded on three sides by the urban landscape of Mumbai and Thane cities. The study area also included 85 km2 of an adjoining protected area, Tungareshwar Wildlife Sanctuary (TWLS), which is surrounded by a combination of forests, rural areas and agricultural lands. Based on spatial capture—recapture framework we observed that leopard densities in SGNP (26.34 ± 4.96 leopards/100 km2) and TWLS (5.40 ± 2.99 leopards/100 km2) were vastly different. We found that density estimates of wild prey and domestic dogs were higher in SGNP in comparison to TWLS. In both the protected areas (PAs), domestic dogs formed a major proportion of leopard diet and were the single highest species contributors. Our study shows that despite extremely high human density around SGNP (~20,000 people/km2), leopard density is also much higher than the adjoining TWLS which has a comparatively lower surrounding density of people (~1,700 people/km2). Leopard density reported from SGNP is amongst the highest ever reported. This interesting result is probably due to much higher biomass of potential food resources in and around SGNP. Studying this relationship between leopards and their prey (both wild and domestic) in a human dominated landscape will give us valuable insights on human—leopard interactions. The two adjacent and connected PAs are similar ecologically, but differ widely in almost all other aspects, including human densities along the periphery, leopard densities, prey densities as well as management regimes.

The Integral Nature of Encounter Rate in Predicting Livestock Depredation Risk

Carnivore depredation of livestock is one of the primary drivers of human-carnivore conflict globally, threatening the well-being of livestock owners, and fueling large carnivore population declines. Interventions designed to reduce carnivore depredation typically center around predictions of depredation risk. However, these spatial risk models tend to be informed by data depicting the number of livestock attacked by carnivores. Importantly, such models omit key stages in the predation sequence which are required to predict predation risk, or in this case depredation risk. Applying the classic predation risk model defined by Lima and Dill demonstrates that depredation risk is dependent upon quantifying the rates at which carnivores encounter livestock before attacking. However, encounter rate is challenging to estimate, necessitating novel data collection systems. We developed and applied such a system to quantify carnivore-livestock encounters at livestock corrals (i.e., bomas) across a 9-month period in Central Kenya. Concurrently, we monitored the number of livestock attacked by carnivores at these bomas. We calculated carnivore-livestock encounter rates, attack rates, and depredation risk at the boma. We detected 1,383 instances in which carnivores encountered livestock at the bomas. However, we only recorded seven attacks. We found that the encounter rate and attack rate for spotted hyenas were almost six and three times higher than that for any other species, respectively. Consequently, spotted hyenas posed the greatest depredation risk for livestock at the boma. We argue that better understanding of carnivore-livestock encounter rates is necessary for effective prediction and mitigation of carnivore depredation of livestock.

Diverse Locations and a Long History: Historical Context for Urban Leopards (Panthera pardus) in the Early Anthropocene From Seoul, Korea

While the urban landscapes of the early Anthropocene may appear hostile to large carnivores, humans and leopards (Panthera pardus) are known to co-inhabit major urban centres like Mumbai (India), Nairobi (Kenya) and Johannesburg (South Africa). We provide evidence that the presence of leopards in urban landscapes is not, however, a new phenomenon and has occurred repeatedly over the early history of the Anthropocene. Using records of Amur leopards (P. p. orientalis) in Seoul, Korea, at the end of the 19th century, a capital city and major urban centre with a high human population density, we explore socio-cultural, political and ecological factors that may have facilitated human-leopard co-occurrence in an urban landscape and the factors that eventually led to the leopards' extirpation. We suggest that, in the absence of unsustainable levels of persecution by humans, leopards are able to persist in urban landscapes which contain small patches of dense vegetation and have sufficient alternative food supplies. In light of the continued expansion of urban landscapes in the 21st century and increasing conservation focus on the presence of large carnivore populations there, this paper provides historical context to human co-existence with leopards in urban landscapes during the Anthropocene–and what we can learn from it for the future.

Changes in the large carnivore community structure of the Judean Desert in connection to Holocene human settlement dynamics

Investigating historical anthropogenic impacts on faunal communities is key to understanding present patterns of biodiversity and holds important implications for conservation biology. While several studies have demonstrated the human role in the extinction of large herbivores, effective methods to study human interference on large carnivores in the past are limited by the small number of carnivoran remains in the paleozoological record. Here, we integrate a systematic paleozoological survey of biogenic cave assemblages with the archaeological and paleoenvironmental records of the Judean Desert, to reveal historical changes in the large carnivore community. Our results show a late Holocene (~ 3400 years ago) faunal reassembly characterized by the diminishment of the dominant large carnivoran, the Arabian leopard (Panthera pardus sbsp. nimr), and the spread of the Syrian striped hyena (Hyaena hyaena sbsp. syriaca). We suggest that increased hunting pressure in combination with regional aridification were responsible for the decrease in the number of leopards, while the introduction of domestic animals and settlement refuse brought new scavenging opportunities for hyenas. The recent extirpation of leopards from the region has been a final note to the Holocene human impact on the ecosystem.

Linking Human Perceptions and Spotted Hyena Behavior in Urban Areas of Ethiopia

Humans have shaped carnivore behavior since at least the Middle Paleolithic period, about 42,000 years ago. In more recent times, spotted hyenas (Crocuta crocuta) in Ethiopia have adapted to living in urban areas, while humans have adapted to living with hyenas. Yet, relationships between coexisting humans and carnivores are rarely addressed beyond mitigating conflicts. We provided a case study for how to broadly think about coexistence and how to study it when measuring if humans and carnivores affect one another. We collected data in four Ethiopian cities: Mekelle, Harar, Addis Ababa, and Arba Minch. We held focus groups and key informant interviews that incorporated feedback from 163 people, representing a wide array of religious, economic, and educational backgrounds. We also determined how many hyenas resided in these cities, hyena behavioral responses to humans using a flight initiation test, and problem-solving abilities via puzzle box trials. We found that in three of the cities, hyenas and humans coexist at high densities and frequently encounter each other. While all participants recognized the importance of hyenas as scavengers to maintain a clean environment, there was pronounced variation in cultural perspectives across cities. For example, while the people of Harar revere hyenas in spiritual terms, in Arba Minch hyenas were regarded as nuisance animals. Hyenas were universally respected as a formidable predator across cities but reports of attacks on livestock and humans were few. Flight initiation tests revealed hyenas fled at significantly closer distances in Harar and Addis Ababa than in Mekelle. Hyenas succeeded at solving a puzzle box in Harar but not in Mekelle. These variable behavior in hyenas correlated to different human perceptions. Our case study results suggest that the hyena-human dynamic is highly variable across these locations. We conclude by exploring the implications of these findings for how humans and hyenas can shape one another's behavior. Developing studies to link human perceptions and animal behavior could advance wildlife conservation, especially in urban areas.

Case series of hyena bite injuries and their surgical management in a resource-limited setup: 1-year experience

Animal bites are a significant cause of morbidity and mortality and pose a major public health problem worldwide. Children are reportedly the most common victims of animal bites. Bites may be limited to superficial tissues or lead to extensive disfiguring injuries, fractures, infections and rarely result in death. Recently, human injuries caused by non-domesticated animals are increasingly common as ecosystems change and humans encroach on previously wild land. Wild animals like hyenas have been reported to prey on humans and cattle in parts of Africa. Discussed here are four children out of 11 patients that presented with hyena bites-the children had severe bites to the face and head with extensive soft tissue loss, fractures and concomitant severe infections that led to high mortality, indicating the necessity for advanced intensive care and multidisciplinary treatment needed in such situations.

Changing ecologies, shifting behaviours: Behavioural responses of a rainforest primate, the lion-tailed macaque Macaca silenus, to a matrix of anthropogenic habitats in southern India

With the uncontrolled expansion of anthropogenic modifications of the environment, wildlife species are forced to interact with humans, often leading to conflict situations that have detrimental effects for both wildlife and humans. Such interactions are escalating globally, making it crucial for us to devise strategies for both, the management of conflict and the conservation of these often-threatened species. We studied a case of potentially detrimental human-wildlife interactions between an endemic, habitat-specialist primate, the lion-tailed macaque Macaca silenus and resident human communities that has developed in recent years in the Western Ghats mountains of southern India. Primates provide useful model systems to understand the extent and nature of behavioural changes exhibited by wildlife in response to anthropogenic habitats with varying degrees of human influence. We documented behaviours, including foraging and intra-species social interactions, to examine the decisions made by the macaques as they exploited four human-modified habitats, which, for the purpose of this study, have been qualitatively characterised to include structural features of the habitat, type of food resources available and the presence of humans. Access to human-origin food, either cooked or packaged, acquired directly from homes or garbage pits, in the human-dominated habitat appeared to significantly reduce active foraging and searching for food, allowing them to engage in other behavioural activities, such as resting. Furthermore, patterns of reciprocated affiliation dissipated in certain human-dominated habitats, with individuals seeming to have adopted novel behavioural strategies, leading to altered social dynamics in the troop, possibly in response to provisioning. This study thus highlights the importance of understanding behavioural changes displayed by animals in response to human interactions; such knowledge could be crucial for the planning and implementation of management and conservation strategies for endangered species such as the lion-tailed macaque and possibly other wildlife in the increasingly anthropogenic landscapes of the tropical world.

Shelter availability and human attitudes as drivers of rock hyrax (Procavia capensis) expansion along a rural-urban gradient

While anthropogenic land-use changes threaten wildlife globally, some species take advantage of such changes and disperse into urban areas. The wildlife in urban areas often promotes conflicts with humans, notably when the animals are associated with the spread of zoonotic diseases. In Israel, current urban invasion of rock hyraxes (Procavia capensis) draws public attention, since the species is a reservoir host of cutaneous leishmaniasis, a serious skin disease. The rock hyrax, however, has seldom been studied in densely populated areas, and the drivers for its urban expansion, as well as its abilities to live and spread in core urban areas, are relatively unknown. Here, we explore the rock hyrax expansion to urban areas process by examining the availability, characteristics and use of shelter along an urban gradient. Our findings suggest that a series of factors determines shelter availability and quality for the rock hyrax, which facilitates its dispersion across the urban gradient. We found that rock hyraxes from the Judean Desert expand to the peri-urban region of Jerusalem by colonizing new rocky shelters formed as by-products of urban development. With their populations reaching extreme densities in this area and saturating the available shelters, there is some spill over to the adjacent core urban areas where they colonize littered sites, which are made available due to the local socio-economic conditions and cultural norms of waste disposal and illegal placement of temporary structures. Our work emphasizes the significance of the urban gradient approach for studying the mechanisms promoting wildlife expansion to cities. Our findings suggest that changes in shelter availability and quality due to urban development, and cultural norms promote shifts of the hyrax population by pushing from the already established areas and pulling into new environment across the urban gradient.

Activity and social interactions in a wide-ranging specialist scavenger, the Tasmanian devil (Sarcophilus harrisii), revealed by animal-borne video collars

Observing animals directly in the field provides the most accurate understanding of animal behaviour and resource selection. However, making prolonged observation of undisturbed animals is difficult or impossible for many species. To overcome this problem for the Tasmanian devil (Sarcophilus harrisii), a cryptic and nocturnal carnivore, we developed animal-borne video collars to investigate activity patterns, foraging behaviour and social interactions. We collected 173 hours of footage from 13 individual devils between 2013 and 2017. Devils were active mostly at night, and resting was the most common behaviour in all diel periods. Devils spent more time scavenging than hunting and exhibited opportunistic and flexible foraging behaviours. Scavenging occurred mostly in natural vegetation but also in anthropogenic vegetation and linear features (roads and fence lines). Scavenging frequency was inversely incremental with size e.g. small carcasses were scavenged most frequently. Agonistic interactions with conspecifics occurred most often when devils were traveling but also occurred over carcasses or dens. Interactions generally involved vocalisations and brief chases without physical contact. Our results highlight the importance of devils as a scavenger in the Tasmanian ecosystem, not just of large carcasses for which devils are well known but in cleaning up small items of carrion in the bush. Our results also show the complex nature of intraspecific interactions, revealing greater detail on the context in which interactions occur. In addition, this study demonstrates the benefits of using animal-borne imaging in quantifying behaviour of elusive, nocturnal carnivores not previously seen using conventional field methods.

Variation in Neotropical river otter (Lontra longicaudis) diet: Effects of an invasive prey species

Predation is one of the main barriers that exotic species may face in newly colonized areas and may help stop or control the potential negative impacts of invasive species in the environment. We evaluated if the consumption of an invasive prey (armored catfish: Pterygoplichtys sp.) affects the dietary niche breadth and trophic level of a native predator (Neotropical river otter: Lontra longicaudis) in northern Guatemala. We examined otter scats from three rivers: two where the invasive armored catfish occurred and one without the invasive fish. Samples were collected two and seven years after the first report of the catfish in the area. We performed gross scat analysis and stable isotope analyses of nitrogen and carbon of fecal matter. Where the invasive armored catfish occurred, it was the main prey item for L. longicaudis. Particularly in the river outside of protected areas seven years after the first report of the catfish, where it accounted for 49% of the otter diet. Concordance was found between the two techniques to estimate dietary niche breadth and trophic level. The dietary niche breath of otters was narrower seven years after the invasion in comparison to two years after the invasion in both invaded rivers, but the extent of the reduction was lesser inside the protected area. Finally, the trophic level of otters also showed a reduction related to the occurrence of the armored catfish in their diet.

Beyond Assuming Co-Benefits in Nature-Based Solutions: A Human-Centered Approach to Optimize Social and Ecological Outcomes for Advancing Sustainable Urban Planning

Urbanization deletes and degrades natural ecosystems, threatens biodiversity, and alienates people from the experience of nature. Nature-based solutions (NbS) that are inspired and supported by nature have the potential to deliver multifunctional environmental and social benefits to address these challenges in urban areas under context-specific conditions. NbS implementation often relies on a one-size-fits-all approach, although interventions that maximize one benefit (e.g., biodiversity conservation) may have no influence on, or even negatively affect, others (e.g., social justice). Furthermore, the current pathways from NbS to various benefits do not rely on a deep understanding of the underlying processes, prohibiting the identification of optimal solutions that maximize synergies across pathways. We present a comprehensive socio-ecological framework that addresses these issues by recognizing that cities are human-dominated environments that are foremost built and maintained to support humans. Our framework demonstrates how we can use experiments and niche species models to understand and predict where species will be and where people will be healthy and happy in a comparable manner. This knowledge can then be integrated into decision support tools that use optimization algorithms to understand trade-offs, identify synergies, and provide planners with the tools needed to tailor context-specific NbS to yield greener, more resilient cities with happier people and reduced inequality.

The mesoscavenger release hypothesis and implications for ecosystem and human well-being

Many apex scavenger species, including nearly all obligate scavengers, are in a state of rapid decline and there is growing evidence these declines can drastically alter ecological food webs. Our understanding of how apex scavengers regulate populations of mesoscavengers, those less-efficient scavengers occupying mid-trophic levels, is improving; yet, there has been no comprehensive evaluation of the evidence around the competitive release of these species by the loss of apex scavengers. Here we present current evidence that supports the mesoscavenger release hypothesis, the increase in mesoscavengers and increase in carrion in the face of declining apex scavengers. We provide two models of scavenger dynamics to demonstrate that the mesoscavenger release hypothesis is consistent with ecological theory. We further examine the ecological and human well-being implications of apex scavenger decline, including carrion removal and disease regulation services.

The contribution of predators and scavengers to human well-being

Predators and scavengers are frequently persecuted for their negative effects on property, livestock and human life. Research has shown that these species play important regulatory roles in intact ecosystems including regulating herbivore and mesopredator populations that in turn affect floral, soil and hydrological systems. Yet predators and scavengers receive surprisingly little recognition for their benefits to humans in the landscapes they share. We review these benefits, highlighting the most recent studies that have documented their positive effects across a range of environments. Indeed, the benefits of predators and scavengers can be far reaching, affecting human health and well-being through disease mitigation, agricultural production and waste-disposal services. As many predators and scavengers are in a state of rapid decline, we argue that researchers must work in concert with the media, managers and policymakers to highlight benefits of these species and the need to ensure their long-term conservation. Furthermore, instead of assessing the costs of predators and scavengers only in economic terms, it is critical to recognize their beneficial contributions to human health and well-being. Given the ever-expanding human footprint, it is essential that we construct conservation solutions that allow a wide variety of species to persist in shared landscapes. Identifying, evaluating and communicating the benefits provided by species that are often considered problem animals is an important step for establishing tolerance in these shared spaces.

Spotted hyaena space use in relation to human infrastructure inside a protected area

Increasing human population growth has led to elevated levels of human-carnivore conflict. However, some carnivore populations have adapted to urban environments and the resources they supply. Such associations may influence carnivore ecology, behaviour and life-history. Pockets of urbanisation sometimes occur within protected areas, so that anthropogenic influences on carnivore biology are not necessarily confined to unprotected areas. In this study we evaluated associations between human infrastructure and related activity and space use of spotted hyaenas within one of the largest protected areas in South Africa, the Kruger National Park. Home range size was smaller for the dominant female of a clan living in close proximity to humans than that of the dominant female of a clan without direct access to human infrastructure. The home range including human infrastructure was also used less evenly during the night, presumably when the animals were active. Within this home range, a village area was preferred during the night, when the least modified areas within the village were preferred and administration and highly modified areas were avoided. During the day, however, there were no preference or avoidance of the village area, but all habitats except unmodified habitats within the village area were avoided. We suggest that human infrastructure and associated activity influenced hyaena space use, primarily through alterations in the spatial distribution of food. However, these effects may have been indirectly caused by habitat modification that generated favourable hunting habitat rather than a direct effect caused by access to human food such as garbage. Because of the often pivotal effects of apex predators in terrestrial ecosystems, we encourage further work aimed to quantify how human presence influences large carnivores and associated ecosystem processes within protected areas.