Viability Of Wildlife Populations Research Articles

Can genetic rescue help save Arabia's last big cat?

Genetic diversity underpins evolutionary potential that is essential for the long-term viability of wildlife populations. Captive populations harbor genetic diversity potentially lost in the wild, which could be valuable for release programs and genetic rescue. The Critically Endangered Arabian leopard (Panthera pardus nimr) has disappeared from most of its former range across the Arabian Peninsula, with fewer than 120 individuals left in the wild, and an additional 64 leopards in captivity. We (i) examine genetic diversity in the wild and captive populations to identify global patterns of genetic diversity and structure; (ii) estimate the size of the remaining leopard population across the Dhofar mountains of Oman using spatially explicit capture-recapture models on DNA and camera trap data, and (iii) explore the impact of genetic rescue using three complementary computer modeling approaches. We estimated a population size of 51 (95% CI 32-79) in the Dhofar mountains and found that 8 out of 25 microsatellite alleles present in eight loci in captive leopards were undetected in the wild. This includes two alleles present only in captive founders known to have been wild-sourced from Yemen, which suggests that this captive population represents an important source for genetic rescue. We then assessed the benefits of reintroducing novel genetic diversity into the wild population as well as the risks of elevating the genetic load through the release of captive-bred individuals. Simulations indicate that genetic rescue can improve the long-term viability of the wild population by reducing its genetic load and realized load. The model also suggests that the genetic load has been partly purged in the captive population, potentially making it a valuable source population for genetic rescue. However, the greater loss of its genetic diversity could exacerbate genomic erosion of the wild population during a rescue program, and these risks and benefits should be carefully evaluated. An important next step in the recovery of the Arabian leopard is to empirically validate these conclusions, implement and monitor a genomics-informed management plan, and optimize a strategy for genetic rescue as a tool to recover Arabia's last big cat.

Regime shift in the interaction between domestic livestock and the deer-tiger food chain

The effects of grazing on wildlife have received considerable attention. Depending on factors such as its intensity and duration, grazing can impact higher-level species along the food chain through competition for available resources with wild herbivores. However, relatively few studies have investigated whether there are tipping points at which grazing intensity begins to seriously impact wildlife. In particular, studies that assess the impact of overgrazing on food chains that include carnivores remain scarce. We developed a time dynamic, age-structured model for the wild ungulates-Amur tiger trophic chain, including cattle grazing as a disturbance. We explored 1) the impact of cattle grazing intensity on the long-term behaviour of the wildlife population; 2) the effect of demographic parameters on wildlife population viability; and 3) the temporal dynamic impact of periods of heavy grazing on the population trajectory. Our results showed that increasing cattle density reaches a tipping point, triggering a rapid and significant shift in wildlife population size. Below the tipping point, wildlife can coexist with grazing livestock; when cattle density exceeds the tipping point, wild ungulate and tiger populations move towards extinction. In the case of heavy grazing, the dynamics of the wild ungulate population was more affected by its intensity, and the dynamics of the Amur tiger population was more affected by its duration. Our model and results suggest that theoretically wildlife conservation and cattle production can coexist but that serious regime shifts in wildlife populations may occur if grazing intensity exceeds a tipping point. These findings provide new insights useful for developing policies related to balancing livestock and wildlife conservation.

Wildlife corridor degradation and human‐wildlife conflict: A case study from Tanzania

AbstractIn many African countries, anthropogenic pressure and poor governance have led to the degradation of wildlife corridors, which are important for the long‐term viability of wildlife populations. Yet the nature of such degradation is poorly understood, hindering our ability to reverse these trends. We studied a deteriorating wildlife corridor between Katavi and Mahale National Parks in western Tanzania. Using satellite imagery, we found that the corridor still contains large areas of natural vegetation, diverse terrain and numerous water sources. There has nonetheless been increasing encroachment of the corridor by people between 1990 and 2017, exemplified by a 9% reduction in the area covered by miombo woodlands and a fourfold increase in the area covered by settlements and agricultural land. We used three additional methods to assess deterioration over the last three decades: elephants' movement routes, peoples' perception of animal populations and incidents of human–wildlife conflicts. Elephants were primarily found only in the parts of the corridor adjacent to the two national parks. Tracking of elephant spoor revealed a much‐diminished corridor use, suggesting that seemingly ‘healthy’ habitat within a wildlife corridor will not necessarily predict the presence of elephants or perhaps of other species. Other factors particularly the increasing presence of humans in the area are possibly more important for predicting elephant use of a corridor. Interviews with local residents and conservation experts suggested that, although use by some animal species has declined, many ungulates were still seen in the corridor and neighbouring villages, some of which were associated with human–wildlife conflict. All villages around the corridor were affected by the human–wildlife conflict; this comprised crop damage, livestock injury or killing and attacks on humans. We conclude that corridors could be restored if people were restricted from settling, but this would require governments to enact policies that balance the conservation of Natural Capital with survival of human populations; the latter may involve internal migration in response to growing population pressures.

Effects of open space configurations and development patterns on future urban wildlife habitats and populations

The viability of wildlife populations in cities is strongly associated to the qualities of urban open spaces and development patterns. Open space systems can serve as armatures to address adverse effects of urbanization on biodiversity. Landscape planners and designers use spatial concepts to translate principles of landscape ecology into working diagrams of land use and land cover to anticipate ecological effects. This paper investigates the consequences of adopting different open space spatial concepts (corridors, patches, and network) in combination with development patterns (compact and dispersed), simulated in eight alternative future scenarios with computer model Envision. Two approaches were used to quantify the effects of the different spatial concepts and urban patterns on Red-legged frog (RLF), Western meadowlark (WML), and Douglas squirrel (DSQ) habitats and populations in an area of urban expansion. First, the amount of habitats was assessed for the initial landscape (ca. 2010) and for the eight future scenarios (year 2060). Second, using the Individual-Based Model (IBM) HexSim, populations of the three species were quantified. All scenarios had increased sums of habitat area, but results showed that differences in open space spatial concepts played a greater role in determining population sizes and were more influential than different development patterns. Network scenarios presented more habitats and the largest populations of RLF. Park and network scenarios showed the most habitats and populations for the WML. No open space and greenway scenarios did not have enough habitats for the WML, but presented the best results for the DSQ. Populations in compact development scenarios showed a small advantage over most dispersed development scenarios. However, in park and network scenarios, dispersed development showed a large influence in the increase of WML population. The study shows that the adopted framework is useful to predict the consequences of landscape plans on wildlife species populations, evaluate trade-offs, and inform planning decisions.

Vertebrates’ roadkill in the southern region of the Atlantic Forest, Paraná coast – Brazil

Being a significant global biodiversity hotspot, the Atlantic Forest has been drastically reduced by human activities. Among the anthropic activities that most affect the biodiversity of this biome is the construction and operation of roads and highways. Between harmful effects of these infrastructures, wildlife roadkill is currently considered one of the biggest causes of mortality of wild vertebrates. This study evaluated patterns of vertebrates' roadkill on two roads in the coastal region of the largest continuous remnant of the Brazilian Atlantic Forest. For twelve months, we carry out weekly samples with a motor vehicle at a constant speed of 40 km/h to search for carcasses along the roads. All carcasses found were georeferenced and identified to the lowest possible taxonomic level. Then, using Siriema v.2.0 software, we analyzed roadkill aggregation and the spatial distribution of hotspots of wildlife roadkill. In 43 sampling days, 209 road-killed animals were registered (average roadkill rate of 0.105 and 0.111 animals/kilometer/day for PR-407 e PR-508, respectively). Extrapolating the rates found, we estimate that about 1,773 animals can be roadkill every year on these roads. The most affected groups were birds (33.01%) and amphibians (30.62%), followed by reptiles (19.13%) and mammals (17.33%). Warmer months had the highest roadkill rates. We found two critical roadkill hotspots for the PR-407 (kilometer 11.7 to 12.5 and kilometer 14.7 to 16.7). For the PR-508, we found a critical point of 5.2 km (kilometer 5 to 10.2). As a short-term measure, we recommend installing speed reducers in the identified stretches and implementing environmental education campaigns with residents and tourists, especially during the summer months, aiming to mitigate the roadkill on both roads. However, due to the importance and environmental fragility of the area, we emphasize the need for running periodic road ecology and local wildlife population viability studies in the medium and long term.

Seabirds under environmental pressures: Food supplementation has a larger impact than selenium on chicks exposed to mercury and a viral disease

Although infectious disease outbreaks represent a serious threat for wildlife population viability, the environmental factors that underlie such outbreaks are poorly investigated. The French Guiana breeding population of Magnificent frigatebird Fregata magnificens is subjected to recurrent episodes of chicks’ mortality likely caused by a viral disease. We hypothesized that high mercury (Hg) concentrations may be responsible for the emergence of clinical signs. We therefore investigated whether healthy and sick chicks show different Hg concentrations in blood. Because the essential element selenium (Se) may be highly depleted during Hg poisoning, we further experimentally tested whether an increased intake of dietary Se has an effect on blood levels of Hg, increases circulating Se, and improves the oxidative status of chicks. Finally, we compared the results of this experiment with a previous food supplementation experiment. Our results show similar Hg concentrations between healthy and sick chicks with visible clinical signs of the disease. Se concentrations were significantly depleted in sick chicks. Se concentrations increased while Hg concentrations simultaneously decreased in chicks that naturally recovered from the disease. Both the Se and fish supplementation experiments significantly increased Se concentrations in blood, while Hg levels were only modestly affected. Providing food to chicks appeared to have greater benefits than only supplementing chicks with Se pills as, although food supplementation had an impact on blood Se similar to that of supplementation with Se pills, it also reduced the vulnerability of chicks to the viral disease, possibly by reducing nutritional stress and providing essential nutrients.

Spatiotemporal Dynamics of Landscape Transformation in Western Balkans’ Metropolitan Areas

Human-caused landscape transformation represents a danger to conserving the Earth’s natural habitats. Landscape fragmentation (LF) caused by transportation infrastructure and urban development poses a threat to human and environmental health by increasing traffic noise and pollution, reducing the size and viability of wildlife populations, facilitating the spread of invasive species, and reducing the recreational qualities of the landscape. It is especially noticeable in the metropolitan areas of developing countries due to rapid and unsupervised urban sprawl. In this context, this study aims to protect natural landscapes and biodiversity, promoting forms of sustainable development. To exemplify our aim, we bring a spatio-temporal analysis of landscape change comparing three metropolitan areas in the Western Balkans (WB). First, we compare the land use land cover (LULC) changes in Tirana (Albania), Skopje (North Macedonia), and Sarajevo (Bosnia and Herzegovina). The comparison was based on the Urban Atlas (UA) data of 2012 and 2018. The analysis was performed on two levels, at the metropolitan and urban spatial scales. Apart from descriptive statistics about the changes in surface area and patch counts, we used effective mesh size (meff) as a landscape metric to quantify the LF level. Our results show that each city has faced significant LULC change between 2012 and 2018, with a dominant increase in artificial surfaces. Furthermore, the cumulative natural surface area reduction is followed by increased landscape patch counts, indicating an increased LF at both levels. This study enhances public awareness about the landscape transformation trends in the developing metropolitan regions of WB. The respective administrative bodies at both local and central levels are invited to consider our results and adopt proper measurements to reduce the adverse consequences of subsequent spatial development decisions.

Considerations for furbearer trapping regulations to prevent grizzly bear toe amputation and injury

AbstractUnder the North American Model of wildlife Conservation, wildlife managers are encouraged to update management approaches when new information arises whose implementation could improve the viability of wildlife populations and the well‐being of animals. Here we detail an observation of several grizzly bears with amputated toes in southeast British Columbia between 2016‐2020 and assemble evidence to inform management strategies to remedy the issue. During the capture of 59 grizzly bears, 4 individuals (~7%) had amputated toes on one of their front feet. The wounds were all healed and linear in nature. Further opportunistic record collection revealed that similar examples of amputated toes occurred beyond our study area in neighboring mountain ranges and internationally. We found evidence that seasonal overlap between the active season for grizzly bears and the fall trapping seasons—for small furbearers with body‐gripping traps and for wolves with foothold traps—were frequently responsible for toe amputation. Photo evidence suggested that body‐gripping traps were the main trap type associated with toe amputation. Multiple options to reduce or eliminate the incidental amputation of grizzly bear toes exist, and the options have varying degrees of expected efficacy and require differing levels of monitoring. One option is to delay the start of the marten trapping season until December 1, when most bears have denned, instead of opening the season on or prior to November 1, when more than 50% of bears are still active. An alternative solution, such as a license condition that requests trappers narrow trap‐box entrances to exclude bear feet while still allowing entrance of target furbearers, has the potential to minimize accidental capture of bears, but the effectiveness of this approach is unknown. Finally, experimental toe extraction trials suggested that better anchoring traps was not a viable solution given that adult grizzly bear feet only came free from body‐gripping traps 20% of the time under maximum human force. At least 230 kg pull was required to consistently free toes from body‐gripping traps, which not all bears will be able to produce unless the cable is long and allows a running start. Solutions that do not involve season changes will require monitoring of efficacy and compliance to ensure success.

Wolves, Crows, Spiders, and People: A Qualitative Study Yielding a Three-Layer Framework for Understanding Human–Wildlife Relations

Human dimensions research has proposed a multitude of variables impacting the viability of wildlife populations. Extant approaches to systematizing these variables have mostly focused on human relations to only one animal species or taxon and are largely descriptive, rather than explanatory. In this study, we provide a three-layer framework for understanding people’s responses to a variety of human–wildlife encounters. We conducted a comparative qualitative study, interviewing 20 stakeholders on one of three ecologically disparate model animals. Through thematic analysis, we identified person-specific, species-specific, and overarching factors whose interplay shapes people’s reactions to encounters with wildlife. The person-specific factors, individual people’s biographic backgrounds and life themes, fuel the polarization of stances towards wildlife. The species-specific factors, people’s mental images of wild animals, explain the particular character of different human–wildlife relations. The overarching factors, fundamental questions regarding the place of humans in nature or motivations of control over animal agents, stir the intensity inherent in human encounters with wildlife. This three-layer framework amends existing proposals by providing a cohesive system and an in-depth portrayal of shared and specific factors and processes in various human–wildlife relations and by elucidating their interaction in influencing people’s responses to encounters with wild animals.

Conservation threats from roadkill in the global road network

AbstractAimThe road network is increasing globally but the consequences of roadkill on the viability of wildlife populations are largely unknown. We provide a framework that allows us to estimate how risk of extinction of local populations increases due to roadkill and to generate a global assessment that identifies which mammalian species are most vulnerable to roadkill and the areas where they occur.LocationGlobal.Time period1995–2015.Major taxa studiedTerrestrial mammals.MethodsWe introduce a framework to quantify the effect of roadkill on terrestrial mammals worldwide that includes three steps: (a) compilation of roadkill rates to estimate the fraction of a local population killed on the roads, (b) prediction of population risk of extinction based on observed roadkill rates (for a target group of species of conservation concern and non‐threatened species with high roadkill rates), and (c) global assessment of vulnerability to roadkill for 4,677 terrestrial mammalian species estimated using phylogenetic regression models that link extinction risk to demographic parameters.ResultsWe identified four populations among the 70 species in the target group that could become extinct in 50 years if observed roadkill levels persist in the study areas: maned wolf Chrysocyon brachyurus (Brazil), little spotted cat Leopardus tigrinus (Brazil), brown hyena Hyaena brunnea (Southern Africa) and leopard Panthera pardus (North India). The global assessment revealed roadkill as an added risk for 2.7% (n = 124) terrestrial mammals, including 83 species Threatened or Near Threatened. We identified regions of concern that have species vulnerable to roadkill with high road densities in areas of South Africa, central and Southeast Asia, and the Andes.Main conclusionsOur framework revealed populations of threatened species that require special attention and can be incorporated into management and planning strategies informing road managers and conservation agencies.

Genetic signatures of population bottlenecks, relatedness, and inbreeding highlight recent and novel conservation concerns in the Egyptian vulture.

The assessment of temporal variation in genetic features can be particularly informative on the factors behind demography and viability of wildlife populations and species. We used molecular methods to evaluate neutral genetic variation, relatedness, bottlenecks, and inbreeding in a declining population of Egyptian vulture (Neophron percnopterus) in central Spain. The results show that the genetic diversity remained relatively stable over a period of twelve years despite the decline in census and effective population sizes in the last decades. A relatively high proportion of nestlings from different and distant territories showed high relatedness in each study year. We also found support for an increasing impact of severe recent (contemporary) rather than distant (historical) past demographic bottlenecks, and the first evidence of inbred mating between full siblings coinciding with lethal malformations in offspring. The inbred nestling with feather malformations was positive to beak and feather disease virus recorded for the first time in this species. These results alert on recent and novel threats potentially affecting health and reducing the adaptive potential of individuals in this threatened species.

Urban open spaces from a dispersal perspective: lessons from an individual-based model approach to assess the effects of landscape patterns on the viability of wildlife populations

Green areas drawn on a city plan represent open spaces that have different meanings for humans and wildlife. Diverse kinds of green may influence species viability in urban environments. It is necessary to understand what those areas mean for wildlife populations and how land-use changes affect habitats and movements for making scientifically defensible planning and design decisions. My objective was to demonstrate how open space and urban development patterns affect the viability of wildlife populations in urbanizing landscapes from a movements perspective. Eight scenarios for 2060 for an urbanizing area near Portland, Oregon combined four open space (none, corridors, parks, and network) with two urban development patterns (compact and dispersed). Dispersal model HexSim simulated three target species – Red-legged frog (Rana aurora aurora), Western meadowlark (Sturnella neclecta) and Douglas squirrel (Tamasciurus douglasii) – movements on those scenarios to compare and contrast sustained populations to the ca. 2010 baseline landscape. Network scenarios presented the largest number of frog breeders. Greenway scenarios showed the largest populations of squirrels. Park and network scenarios sustained viable populations of meadowlarks, but park scenarios performed best. Compact development scenarios performed best for most indicators, while dispersed development scenarios performed better for meadowlarks. Network scenarios performed best when considering the collective of species. Networks presented more diverse habitats, sustaining higher diversity of species. For plans to sustain more species, more comprehensive and diverse habitats must be promoted, otherwise trade-offs should be expected – like the extinction of meadowlarks in greenway scenarios.

Not all urban landscapes are the same: interactions between urban land use and stress in a large herbivorous mammal.

Urbanization significantly impacts the health and viability of wildlife populations yet it is not well understood how urban landscapes differ from non-urban landscapes with regard to their effects on wildlife. This study investigated the physiological response of eastern grey kangaroos (Macropus giganteus) to land use at a landscape scale. Using fecal glucocorticoid metabolites (FGM) we compared stress levels of kangaroo populations in urban and non-urban environments. We modeled FGM concentrations from 24 kangaroo populations against land use (urban or non-urban) and other anthropogenic and environmental factors, using a linear modeling approach. We found that land use was a significant predictor of FGM concentrations in eastern grey kangaroos with significant differences in concentrations between urban and non-urban populations. However, the direction of the relationship differed between northern and southern regions of Australia. In the northern study sites, kangaroos in urban areas had significantly higher FGM levels than their non-urban counterparts. In contrast, in southern sites, where kangaroos occur in high densities in many urban areas, urban kangaroos had lower FGM concentrations than non-urban kangaroos. Rainfall and temperature were also significant predictors of FGM and the direction of the relationship was consistent across both regions. These results are consistent with the contrasting abundance and persistence of kangaroo populations within the urban matrix between the two study regions. In the northern region many populations have declined over the last two decades and are fragmented, also occurring at lower densities than in southern sites. Our study indicates that it is the characteristics of urban environments, rather than the urban environment per se, which determines the extent of impacts of urbanization on kangaroos. This research provides insights into how the design of urban landscapes can influence large mammal populations.

The Importance of Reproduction for the Conservation of Slow-Growing Animal Populations.

Both survival and reproduction are important fitness components, and thus critical to the viability of wildlife populations. Preventing one death (survival) or contributing one newborn (reproduction), has arguably the same effect on population dynamics-in each instance the population grows or is maintained by one additional member. However, for the conservation of slow-growing animal populations, the importance of reproduction is sometimes overlooked when evaluating wildlife management options. This has to do with the use of demographic sensitivity analyses, which quantify the relative contribution of vital rates to population growth. For slow-growing populations, the results of such analyses typically show that growth rates are more sensitive to changes in survival than to equal proportional changes in reproduction. Consequently, for slow-growing taxa, survival has been labelled a better fitness surrogate than reproduction. However, such a generalization, derived from conventional sensitivity analyses, is based on flawed approaches, such as omitting appropriate scaling of vital rates, and sometimes misinterpretations. In this chapter, I make the case that for the conservation of slow-growing species the role of reproduction is considerably greater than conventional sensitivity analyses would suggest. This is illustrated by case studies on wildlife populations that underscore the importance of reproduction for the conservation of slow-growing birds, ungulates, carnivores, and cetaceans.

An objective road risk assessment method for multiple species: ranking 166 reptiles and amphibians in California

ContextTransportation and wildlife agencies may consider the need for barrier structures and safe wildlife road-crossings to maintain the long-term viability of wildlife populations. In order to prioritize these efforts, it is important to identify species that are most at risk of extirpation from road-related impacts.PurposeOur goal was to identify reptiles and amphibians in California most susceptible to road mortality and fragmentation. With over 160 species and a lack of species-specific research data, we developed an objective risk assessment method based upon road ecology science.MethodsRisk scoring was based upon a suite of life history and space-use characteristics associated with negative road effects applied in a hierarchical manner from individuals to species. We evaluated risk to both aquatic and terrestrial connectivity and calculated buffer distances to encompass 95% of population-level movements. We ranked species into five relative categories of road-related risk (very-high to very-low) based upon 20% increments of all species scores.ResultsAll chelonids, 72% of snakes, 50% of anurans, 18% of lizards and 17% of salamander species in California were ranked at high or very-high risk from negative road impacts. Results were largely consistent with local and global scientific literature in identifying high risk species and groups.ConclusionsThis comparative risk assessment method provides a science-based framework to identify species most susceptible to negative road impacts. The results can inform regional-scale road mitigation planning and prioritization efforts and threat assessments for special-status species. We believe this approach is applicable to numerous landscapes and taxonomic groups.

Using field data to quantify chemical impacts on wildlife population viability.

Environmental pollution is an important driver of biodiversity loss. Yet, to date, the effects of chemical exposure on wildlife populations have been quantified for only a few species, mainly due to a lack of appropriate laboratory data to quantify chemical impacts on vital rates. In this study, we developed a method to quantify the effects of toxicant exposure on wildlife population persistence based on field monitoring data. We established field-based vital-rate-response functions for toxicants, using quantile regression to correct for the influences of confounding factors on the vital rates observed, and combined the response curves with population viability modelling. We then applied the method to quantify the impact of DDE on three bird species: the White-tailed Eagle, Bald Eagle, and Osprey. Population viability was expressed via five population extinction vulnerability metrics: population growth rate (r1 ), critical patch size (CPS), minimum viable population size (MVP), probability of population extirpation (PE), and median time to population extirpation (MTE). We found that past DDE exposure concentrations increased population extirpation vulnerabilities of all three bird species. For example, at DDE concentrations of 25mg/kg wet mass of egg (the maximum historic exposure concentration reported in literature for the Osprey), r1 became small (White-tailed Eagle and Osprey) or close to zero (Bald Eagle), the CPS increased up to almost the size of Connecticut (White-tailed Eagle and Osprey) or West Virginia (Bald Eagle), the MVP increased up to approximately 90 (White-tailed Eagle and Osprey) or 180 breeding pairs (Bald Eagle), the PE increased up to almost certain extirpation (Bald Eagle) or only slightly elevated levels (White-tailed Eagle and Osprey) and the MTE became within decades (Bald Eagle) or remained longer than a millennium (White-tailed Eagle and Osprey). Our study provides a method to derive species-specific field-based response curves of toxicant exposure, which can be used to assess population extinction vulnerabilities and obtain critical levels of toxicant exposure based on maximum permissible effect levels. This may help conservation managers to better design appropriate habitat restoration and population recovery measures, such as reducing toxicant levels, increasing the area of suitable habitat or reintroducing individuals.

Woody vegetation composition and diversity in woodlands inside and outside a Forest Reserve in Jos, Nigeria

AbstractProtected areas such as forest reserves are often assumed to be best ways to conserve biodiversity and maintain intact ecosystems. We examined woody plant composition and diversity in the gallery forest and savannah woodland habitats of Amurum Forest Reserve and areas immediately surrounding it in Jos, Nigeria. A total of 100 10 × 10 m sample plots were established inside and outside the reserve. All woody plants ≥1 cm diameter at breast height (dbh) were identified and measured. A total of 7,564 individual plants categorized as 134 species from 44 families were recorded. Overall species diversity was significantly higher in the Forest Reserve than outside the reserve, although more species were encountered outside the reserve. Our findings suggest that, protected areas and the areas surrounding them are important for the conservation of biodiversity as the areas outside protected areas also contain species of conservation value. The continuous degrading areas outside protected areas isolates them and poses a serious threat to the long‐term viability of wildlife populations, so it is important that biodiversity in protected areas and their surrounding areas be conserved.

Can island specialists succeed as urban pioneers? Pied imperial-pigeons provide a case study

Context Long-term viability of wildlife populations may be influenced by the adaptive or maladaptive nature of behavioural shifts. Yet, in the short term, implications of novel behaviour are often uncertain, as they were for a newly formed urban nesting colony of pied imperial-pigeons (PIPs) on the mainland coast of north-eastern Australia. It represented unprecedented behaviour, as most of PIPs, also known as Torresian imperial-pigeons, Ducula bicolor/spilorrhoa, breed colonially on remote small islands. Aims The present study would (1) determine whether aggregated mainland nesting continued, (2) evaluate reproductive success, (3) evaluate spatial distribution of nests and (4) explore possible association of reproductive success with predator presence and broad indicators of food availability. Methods With assistance from volunteers, we found mainland PIP nests and revisited them intermittently to monitor progress. We calculated quantitative estimates of nest survival by the Mayfield method and evaluated reproductive output in relation to environmental data from independent sources. Key results During the 2012, 2013 and 2014 breeding seasons, we recorded 436, 387 and 417 PIP nest events at the new mainland colony. Daily nest-survival rates declined progressively and estimated fledgling output decreased over successive seasons from 0.66 to 0.44 per nest event. The highest mainland output was below that estimated for an island PIP colony (0.78) on the basis of sparse prior data. Across potential foraging grounds, there was no negative change in land use and no widespread adverse weather to account for diminishing success. We identified important causes of nest failure among mainland nesting PIPs to be predation, predominantly by birds, and anthropogenic hazards, including tree pruning and collisions with vehicles and windows of buildings. Conclusions With ongoing exposure to these hazards, mainland nesting PIPs cannot be expected to increase productivity; hence, the new colony may be a short-term phenomenon. We infer that the historic success of PIP populations in Queensland stems from their selection of breeding sites on remote islands that are largely free of relevant predators and anthropogenic activity. Implications Future conservation of extant PIP abundance will depend crucially on protection of island breeding sites, because multiple hazards of mainland nesting make it an unfavourable alternative strategy.

The role of one health in wildlife conservation: a challenge and opportunity.

Numerous emerging infectious diseases (EIDs) have arisen from or been identified in wildlife, with health implications for both humans and wildlife. In the practice of wildlife conservation, to date most attention has focused on the threat EIDs pose to biodiversity and wildlife population viability. In the popular media and public eye, however, wildlife is often only portrayed as the cause of EIDs and resultant human health impacts. There is little coverage on the roles of human-induced habitat destruction or wildlife population stress in EID spread, nor the negative impacts of disease on wildlife. Here, we focus on a little-studied and seldom discussed concern: how real and perceived risks of wildlife-associated diseases for human and companion animal health might erode public support for wildlife conservation. We believe that wildlife-associated EIDs and public perceptions of these risks are among the most important threats to wildlife conservation. In light of this concern, we explore the challenges and opportunities for addressing this situation in a One Health context that emphasizes the interdisciplinary collaboration and the inextricable nature of human and animal health and disease.

Human encroachment into protected area networks in Zambia: implications for large carnivore conservation

Large carnivores are declining globally, with strong direct and indirect ecological impacts on protected area networks (PANs). Human encroachment on ecosystems is a global threat for large carnivores, particularly in savanna Africa, where increasing human resource demands continue to degrade the connectivity and viability PANs. Zambia has a regionally significant role in large carnivore conservation, given that it borders eight countries, includes three transfrontier conservation areas (TFCAs), and manages nearly 40 % of its land for wildlife. Deforestation in general and encroachment in particular are recognized problems in Zambian natural resource management. However, specific impacts on PANs are poorly understood owing to a lack of adequate mapping of encroachment, deriving from widespread difficulty in mapping cultivation and clearing in fire-prone savannas, and severe inaccuracy in several previous land cover data sets. Using simple manual interpretation of diverse and carefully chosen remote sensing imagery, we evaluated land use change from 1965 to 2011 in Zambia, primarily in the Luangwa Valley. We found widespread encroachment extending toward national parks from major roads as fast as 2 km/year and averaging 18 hectares per hour of daylight throughout a 159,805 km2 study area, eliminating designated buffer zones in some areas, decreasing connectivity, and potentially eliminating viable TFCAs. At current rates, Zambia’s PANs would be expected to be reduced into small isolated pockets primarily centered on national parks, with substantial human edge effects threatening the viability of wildlife populations in the region, particularly wide-ranging, low density, and threatened large carnivores such as African wild dogs, cheetah, and lion. It is thus critical that encroachment is accurately mapped across the entire region and that land use plans are developed, implemented, revised where necessary, and enforced with strong governmental support, enabling protection of these areas and the communities that depend upon them.