Genetic analysis of an isolated red deer (Cervus elaphus) population showing signs of inbreeding depression

Can linear transportation infrastructure verges constitute a habitat and/or a corridor for vascular plants in temperate ecosystems? A systematic review

BACKGROUND

Linear transportation infrastructures (roads, railways, oil and gas pipelines, powerlines and waterways) are recognized as important contributors to the fragmentation of species habitats. On the other hand, verges of linear transportation infrastructures (road and railway embankments, strips of grass under power lines or above buried pipelines, or waterway banks) form vast networks of continuous habitats. While the loss of natural habitats still poses a significant threat to biodiversity, verges can provide habitats or corridors in anthropogenic areas, although this potential for conservation remains controversial. The current paper is the first synthesis of evidence addressing this topic for vascular plants (except strictly aquatic species) in temperate ecosystems. We asked the following question: can linear transportation infrastructure verges constitute habitats and/or corridors for vascular plants in temperate ecosystems?

METHODS

We conducted a systematic literature survey using two online bibliographic databases, three search engines, specialist websites, and by sending a call for literature to subject experts. We also integrated studies from a previous systematic review with an overlapping scope. We successively screened the articles for relevance on titles, abstracts and full texts using criteria detailed in an a priori protocol. We then used six specific questions to categorize the selected studies and critically assess them. These questions encompassed the potential of verges as habitats and corridors for vascular plants, and the effects of landscape and management on these potentialities. We created a database of the studies with low and medium risk of bias. We synthesized results for specific questions in narrative syntheses. Finally, studies about the habitat role of verges that met the criteria for a meta-analysis were used for quantitative syntheses.

REVIEW FINDINGS

Our systematic literature survey yielded 101,524 search results. After critical appraisal, we included in our systematic review 294 articles that reported 316 studies. Most studies were conducted along road verges or waterway banks, with only a handful of studies involving powerlines, railways or pipelines. We were not able to draw conclusions on the role of verges as corridors for vascular plants as too few relevant studies were obtained. Regarding the habitat function of verges however, meta-analyses were conducted based on 205 cases from 47 primary studies that compared abundance and/or species richness in verges vs habitats away from transportation infrastructure for exotic, native or all species together. For non-highway road verges, both the abundance and richness of exotic species were higher on non-highway road verges, but we found no significant differences among species in general, or for native species specifically, which implies that alien species would often add but not subtract species. A wide variety of management practices were also represented in the evidence base. Overall, systematic impacts on species richness or abundance rarely emerged, but human interventions were seldom neutral and usually altered, at least temporarily, the balance between the native and exotic flora or among various functional groups.

CONCLUSIONS

We identified a major knowledge gap regarding the potential of linear transportation infrastructure verges as corridors for vascular plants. Thus, we call for more research on this particular topic, especially as the evidence synthesis underlined the potential of verges as habitat for exotic and invasive flora.

Genetic signature of blind reintroductions of Iberian ibex (Capra pyrenaica) in Catalonia, Northeast Spain

The Iberian ibex is one of the most singular species of the Iberian Peninsula. Throughout the years, this species suffered several threats which led the population to its decline. Many reintroductions and translocations were made, however, none of those actions took into account the genetic patterns of both reintroduced individuals and the target populations. In this paper, we explored the genetic traits of three populations of Iberian ibex in Catalonia, which experienced blind reintroductions in past years: The populations of Iberian ibex from Els Ports de Tortosa i Beseit National Game Reserve (TBNGR), Montserrat Natural Park (Monserrat) and Montgrí, les Illes Medes i el Baix Ter Natural Park (Montgrí) Based on the genetic patterns of the three populations coupled with the absence of genetic introgression with domestic goats–inferred using mitochondrial and nuclear markers–we propose that these should be regarded as two different management units: TBNGR coupled with Montserrat, and Montgrí. Montserrat population should be targeted as a population model for ecology and evolution studies. Although we did not detect evidences of recent bottleneck events, this population seems to be monomorphic for the mtDNA haplotype. Our results suggest that the blind reintroductions from TBNGR to Montserrat failed on maximizing the genetic diversity of the latter. We enhance the importance of genetic monitoring of both the source population and the selected individuals to be re-introduced. We conclude that the three studied population of Iberian ibex must be monitored to explore which strategy would be advantageous for maintaining the genetic diversity. On the other hand, TBNGR should be monitored to assess the existence of its singular genetic variation, where stochastic events could preserve this lost genetic variation.

Host Genetic Diversity and Infectious Diseases. Focus on Wild Boar, Red Deer and Tuberculosis

Host genetic diversity tends to limit disease spread in nature and buffers populations against epidemics. Genetic diversity in wildlife is expected to receive increasing attention in contexts related to disease transmission and human health. Ungulates such as wild boar (Sus scrofa) and red deer (Cervus elaphus) are important zoonotic hosts that can be precursors to disease emergence and spread in humans. Tuberculosis is a zoonotic disease with relevant consequences and can present high prevalence in wild boar and red deer populations. Here, we review studies on the genetic diversity of ungulates and determine to what extent these studies consider its importance on the spread of disease. This assessment also focused on wild boar, red deer, and tuberculosis. We found a disconnection between studies treating genetic diversity and those dealing with infectious diseases. Contrarily, genetic diversity studies in ungulates are mainly concerned with conservation. Despite the existing disconnection between studies on genetic diversity and studies on disease emergence and spread, the knowledge gathered in each discipline can be applied to the other. The bidirectional applications are illustrated in wild boar and red deer populations from Spain, where TB is an important threat for wildlife, livestock, and humans.

Human-driven genetic differentiation in a managed red deer population

Nineteen red deer areas in a densely populated region with a huge network of fenced motorways and the division into administrative management units (AMUs) with restricted ecological connectivity were investigated. In the season 2018/2019, a total of 1291 red deer samples (on average 68 per area) were collected and genotyped using 16 microsatellite markers. The results show a clear genetic differentiation between most of the AMUs. Fourteen AMUs may be combined into four regions with a considerable internal genetic exchange. Five areas were largely isolated or showed only a limited gene flow with neighbouring areas. Ten of the 19 AMUs had an effective population size below 100. Effective population sizes greater than 500–1000, required to maintain the evolutionary potential and a long-term adaptation potential, were not achieved by any of the studied AMUs, even when AMUs with an appreciable genetic exchange were aggregated. Substantial genetic differentiation between areas can be associated with the presence of landscape barriers hindering gene flow, but also with the maintenance of ‘red deer–free’ areas. Efforts to sustainably preserve the genetic diversity of the entire region should therefore focus on measures ensuring genetic connectivity. Opportunities for this goal arise from the establishment of game bridges over motorways and from the protection of young male stags migrating through the statutory ‘red deer–free’ areas.

Anthropogenic pressures increase extinction risk of an isolated Asian elephant (Elephas maximus) population in southwestern China, as revealed by a combination of molecular- and landscape-scale approaches

Identification of the effect of anthropogenic threats on ecosystem is crucial. We used molecular tools and remote sensing to evaluate the population status of an isolated Asian elephant population in southwestern China in response to changes in habitat suitability between 1989 and 2019. A total of 22 unique genotypes were identified from 117 dung samples collected between March and June 2018 using microsatellite DNA analysis, including 13 males and 9 females. Based on the size of fecal boli, 1 animal was a juvenile, 9 were subadults, and 12 were adults, indicating that recruitment was limited. The effective population size was small (15.3) but there was no signature of a recent population bottleneck. We observed a low genetic diversity (H_e = 0.46 ± 0.05) and a high level of inbreeding (F_is of 0.43 ± 0.11), suggesting low population viability and high risk of extinction. In total, these elephants lost nearly two thirds (62%) of their habitat in 3 decades. The expansion of agriculture and rubber plantations followed by an increase in human settlements after 1989 increased the isolation of this population. We recommend that resettlement of 800 inhabitants of 2 villages and the abandonment of associated farmland and rubber plantations would make an additional 20 km² of suitable habitat available. This could allow a population increase of 14 elephants, possibly by translocating individuals from elsewhere in China. Our findings can be applied to the management and conservation of other fragmented populations in China or in other range countries of Asian elephants.

Inbreeding and disease avoidance in a free-ranging koala population

Habitat destruction and fragmentation are increasing globally, forcing surviving species into small, isolated populations. Isolated populations typically experience heightened inbreeding risk and associated inbreeding depression and population decline; although individuals in these populations may mitigate these risks through inbreeding avoidance strategies. For koalas, as dietary specialists already under threat in the northern parts of their range, increased habitat fragmentation and associated inbreeding costs are of great conservation concern. Koalas are known to display passive inbreeding avoidance through sex-biased dispersal, although population isolation will reduce dispersal pathways. We tested whether free-ranging koalas display active inbreeding avoidance behaviours. We used VHF tracking data, parentage reconstruction, and veterinary examination results to test whether free-ranging female koalas avoid mating with (a) more closely related males; and (b) males infected with sexually transmitted Chlamydia pecorum. We found no evidence that female koalas avoid mating with relatively more related available mates. In fact, as the relatedness of potential mates increases, so did inbreeding events. We also found no evidence that female koalas can avoid mating with males infected with C. pecorum. The absence of active inbreeding avoidance mechanisms in koalas is concerning from a conservation perspective, as small, isolated populations may be at even higher risk of inbreeding depression than expected. At risk koala populations may require urgent conservation interventions to augment gene flow and reduce inbreeding risks. Similarly, if koalas are not avoiding mating with individuals with chlamydial disease, populations may be at higher risk from disease than anticipated, further impacting population viability.

Demographic and genetic structure of a severely fragmented population of the endangered hog deer (Axis porcinus) in the Indo-Burma biodiversity hotspot

The population of the globally endangered hog deer (Axis porcinus) has declined severely across its geographic range. Intensive monitoring of its demographic and genetic status is necessary. We examined the demographic and genetic structure of a small hog deer population in Keibul Lamjao National Park (KLNP), located on the western fringe of the Indo-Burma biodiversity hotspot for conservation planning. The distribution pattern of hog deer in the Park was derived based on the presence/absence of faecal pellets in 1 km × 1 km grids. We used double-observer distance sampling method to derive the hog deer abundance and population structure and compared with previous data to derive the population trend. We determined the genetic diversity of the population through microsatellite screening and bottleneck detection. The overall pellet density was 0.34 ± 0.02 pellets km^-2 restricted to only 22.34 ± 0.20 km² area of the park. The estimated density of the deer in the park was 1.82–4.32 individuals km^-2. The population showed a declining trend from 2006–08 (p < 0.05, R² = 0.916) with 8% annum^-1 and an increasing trend from 2003–2018 (p < 0.05, R² = 0.9304) with 10% annum^-1. The adult male-to-female ratio and fawn-to-doe ratio were 36.2 ± 1.9 males per 100 females and 16.5 ± 0.4 fawns per 100 females, respectively. The molecular examination suggested that the mean number of alleles at 23 loci was 2.70 ± 0.18, the observed heterozygosity (Ho) ranged from 0.26 to 0.63 (mean 0.42 ± 0.02), the expected heterozygosity (He) ranged from 0.23 to 0.73 (χ = 0.51 ± 0.03), and the polymorphic information content (PIC) ranged from 0.2 to 0.67 (χ = 0.43 ± 0.03) indicating a moderate level of genetic diversity. Although no bottleneck in the population was observed, the loss of genetic diversity may affect the evolutionary potential of the species at the site by limiting the selection flexibility. Conservation planning coupled with scientific management regime will help in the long term persistence of the population in the region.

Genetic analysis of red deer (Cervus elaphus) administrative management units in a human-dominated landscape

Red deer (Cervus elaphus) throughout central Europe are influenced by different anthropogenic activities including habitat fragmentation, selective hunting and translocations. This has substantial impacts on genetic diversity and the long-term conservation of local populations of this species. Here we use genetic samples from 480 red deer individuals to assess genetic diversity and differentiation of the 12 administrative management units located in Schleswig Holstein, the northernmost federal state in Germany. We applied multiple analytical approaches and show that the history of local populations (i.e., translocations, culling of individuals outside of designated red deer zones, anthropogenic infrastructures) potentially has led to low levels of genetic diversity. Mean expected heterozygosity was below 0.6 and we observed on average 4.2 alleles across 12 microsatellite loci. Effective population sizes below the recommended level of 50 were estimated for multiple local populations. Our estimates of genetic structure and gene flow show that red deer in northern Germany are best described as a complex network of asymmetrically connected subpopulations, with high genetic exchange among some local populations and reduced connectivity of others. Genetic diversity was also correlated with population densities of neighboring management units. Based on these findings, we suggest that connectivity among existing management units should be considered in the practical management of the species, which means that some administrative management units should be managed together, while the effective isolation of other units needs to be mitigated.

Intensive Management and Natural Genetic Variation in Red Deer (Cervus elaphus)

The current magnitude of big-game hunting has outpaced the natural growth of populations, making artificial breeding necessary to rapidly boost hunted populations. In this study, we evaluated if the rapid increase of red deer (Cervus elaphus) abundance, caused by the growing popularity of big-game hunting, has impacted the natural genetic diversity of the species. We compared several genetic diversity metrics between 37 fenced populations subject to intensive management and 21 wild free-ranging populations. We also included a historically protected population from a national park as a baseline for comparisons. Contrary to expectations, our results showed no significant differences in genetic diversity between wild and fenced populations. Relatively lower genetic diversity was observed in the protected population, although differences were not significant in most cases. Bottlenecks were detected in both wild and fenced populations, as well as in the protected population. Assignment tests identified individuals that did not belong to their population of origin, indicating anthropogenic movement. We discuss the most likely processes, which could have led to the observed high levels of genetic variability and lack of differentiation between wild and fenced populations and suggest cautionary points for future conservation. We illustrate our comparative approach in red deer. However, our results and interpretations can be largely applicable to most ungulates subject to big-game hunting as most of them share a common exploitation-recovery history as well as many ecological traits.

Using genetic tools to estimate the prevalence of non-native red deer (Cervus elaphus) in a Western European population

Game species like the red deer have been subjected to anthropogenic impacts for centuries. Translocations are often carried out—sometimes illegally—not only for sporting purposes, but also to increase trophy quality, reduce inbreeding, or mitigate bottlenecks after excessive persecution. Apart from the blurring of large‐scale genetic structure, translocations without adequate quarantine measure risk introducing pathogens into potentially immunologically naïve populations. It is therefore important to understand the frequency of clandestine translocations. Identification of non‐autochthonous animals and their potential origin is often difficult and, in red deer, has been hampered by the lack of large‐scale genotypic datasets for comparison. In the present study, we make use of a recently published European‐wide microsatellite dataset to detect and quantify the presence of non‐autochthonous red deer in a large population sample (n = 1,780) from Central Europe (Belgium). Using factorial correspondence analysis, assignment tests and Bayesian clustering algorithms we arrive at an estimate of 3.7% non‐autochthonous animals (or their descendants). Some of these animals were assigned to a nearby French population and may have immigrated into Belgium naturally, but the large majority must have been introduced by humans. Our analysis pointed to the British Isles and Germany/Poland as the potential origin of many introduced deer, regions known to have been source populations for translocations in Europe and beyond. We found evidence for recreational hunters using carcasses from farmed deer to fulfill mandatory hunting quotas. Our study is the first to quantify the extent of human‐mediated introductions in a European game species at such a large scale with large and representative sample sizes.

Coupling Satellite Data with Species Distribution and Connectivity Models as a Tool for Environmental Management and Planning in Matrix-Sensitive Species

Climate change and anthropogenic habitat fragmentation are considered major threats for global biodiversity. As a direct consequence, connectivity is increasingly disrupted in many species, which might have serious consequences that could ultimately lead to the extinction of populations. Although a large number of reserves and conservation sites are designated and protected by law, potential habitats acting as inter-population connectivity corridors are, however, mostly ignored in the common practice of environmental planning. In most cases, this is mainly caused by a lack of quantitative measures of functional connectivity available for the planning process. In this study, we highlight the use of fine-scale potential connectivity models (PCMs) derived from multispectral satellite data for the quantification of spatially explicit habitat corridors for matrix-sensitive species of conservation concern. This framework couples a species distribution model with a connectivity model in a two-step framework, where suitability maps from step 1 are transformed into maps of landscape resistance in step 2 filtered by fragmentation thresholds. We illustrate the approach using the sand lizard (Lacerta agilis L.) in the metropolitan area of Cologne, Germany, as a case study. Our model proved to be well suited to identify connected as well as completely isolated populations within the study area. Furthermore, due to its fine resolution, the PCM was also able to detect small linear structures known to be important for sand lizards' inter-population connectivity such as railroad embankments. We discuss the applicability and possible implementation of PCMs to overcome shortcomings in the common practice of environmental impact assessments.

Population dynamics of a natural red deer population over 200 years detected via substantial changes of genetic variation

Most large mammals have constantly been exposed to anthropogenic influence over decades or even centuries. Because of their long generation times and lack of sampling material, inferences of past population genetic dynamics, including anthropogenic impacts, have only relied on the analysis of the structure of extant populations. Here, we investigate for the first time the change in the genetic constitution of a natural red deer population over two centuries, using up to 200‐year‐old antlers (30 generations) stored in trophy collections. To the best of our knowledge, this is the oldest DNA source ever used for microsatellite population genetic analyses. We demonstrate that government policy and hunting laws may have strong impacts on populations that can lead to unexpectedly rapid changes in the genetic constitution of a large mammal population. A high ancestral individual polymorphism seen in an outbreeding population (1813–1861) was strongly reduced in descendants (1923–1940) during the mid‐19th and early 20th century by genetic bottlenecks. Today (2011), individual polymorphism and variance among individuals is increasing in a constant‐sized (managed) population. Differentiation was high among periods (F_ST > ***); consequently, assignment tests assigned individuals to their own period with >85% probability. In contrast to the high variance observed at nuclear microsatellite loci, mtDNA (D‐loop) was monomorphic through time, suggesting that male immigration dominates the genetic evolution in this population.

Genetic Structure and Effective Population Sizes in European Red Deer (Cervus elaphus) at a Continental Scale: Insights from Microsatellite DNA

We analyzed more than 600 red deer (Cervus elaphus) from large parts of its European distribution range at 13 microsatellite loci, presenting the first continent-wide study of this species using nuclear markers. Populations were clearly differentiated (overall F ST = 0.166, Jost's D est = 0.385), and the BAPS clustering algorithm yielded mainly geographically limited and adjacent genetic units. When forced into only 3 genetic clusters our data set produced a very similar geographic pattern as previously found in mtDNA phylogeographic studies: a western group from Iberia to central and parts of Eastern Europe, an eastern group from the Balkans to Eastern Europe, and a third group including the threatened relict populations from Sardinia and Mesola in Italy. This result was also confirmed by a multivariate approach to analyzing our data set, a discriminant analysis of principal components. Calculations of genetic diversity and effective population sizes (linkage disequilibrium approach) yielded the lowest results for Italian (Sardinia, Mesola; N e between 2 and 8) and Scandinavian red deer, in line with known bottlenecks in these populations. Our study is the first to present comparative nuclear genetic data in red deer across Europe and may serve as a baseline for future analyses of genetic diversity and structuring in this widespread ungulate.

Admixture of Eastern and Western European Red Deer Lineages as a Result of Postglacial Recolonization of the Czech Republic (Central Europe)

Due to a restriction of the distributional range of European red deer (Cervus elaphus L.) during the Quaternary and subsequent recolonization of Europe from different refugia, a clear phylogeographical pattern in genetic structure has been revealed using mitochondrial DNA markers. In Central Europe, 2 distinct, eastern and western, lineages of European red deer are present; however, admixture between them has not yet been studied in detail. We used mitochondrial DNA (control region and cytochrome b gene) sequences and 22 microsatellite loci from 522 individuals to investigate the genetic diversity of red deer in what might be expected to be an intermediate zone. We discovered a high number of unique mtDNA haplotypes belonging to each lineage and high levels of genetic diversity (cyt b H = 0.867, D-loop H = 0.914). The same structuring of red deer populations was also revealed by microsatellite analysis, with results from both analyses thus suggesting a suture zone between the 2 lineages. Despite the fact that postglacial recolonization of Central Europe by red deer occurred more than 10000 years ago, the degree of admixture between the 2 lineages is relatively small, with only 10.8% admixed individuals detected. Direct translocations of animals by humans have slightly blurred the pattern in this region; however, this blurring was more apparent when using maternally inherited markers than nuclear markers.

Comparative landscape genetics of three closely related sympatric Hesperid butterflies with diverging ecological traits

To understand how landscape characteristics affect gene flow in species with diverging ecological traits, it is important to analyze taxonomically related sympatric species in the same landscape using identical methods. Here, we present such a comparative landscape genetic study involving three closely related Hesperid butterflies of the genus Thymelicus that represent a gradient of diverging ecological traits. We analyzed landscape effects on their gene flow by deriving inter-population connectivity estimates based on different species distribution models (SDMs), which were calculated from multiple landscape parameters. We then used SDM output maps to calculate circuit-theoretic connectivity estimates and statistically compared these estimates to actual genetic differentiation in each species. We based our inferences on two different analytical methods and two metrics of genetic differentiation. Results indicate that land use patterns influence population connectivity in the least mobile specialist T. acteon. In contrast, populations of the highly mobile generalist T. lineola were panmictic, lacking any landscape related effect on genetic differentiation. In the species with ecological traits in between those of the congeners, T. sylvestris, climate has a strong impact on inter-population connectivity. However, the relative importance of different landscape factors for connectivity varies when using different metrics of genetic differentiation in this species. Our results show that closely related species representing a gradient of ecological traits also show genetic structures and landscape genetic relationships that gradually change from a geographical macro- to micro-scale. Thus, the type and magnitude of landscape effects on gene flow can differ strongly even among closely related species inhabiting the same landscape, and depend on their relative degree of specialization. In addition, the use of different genetic differentiation metrics makes it possible to detect recent changes in the relative importance of landscape factors affecting gene flow, which likely change as a result of contemporary habitat alterations.

Effects of recent and past climatic shifts on the genetic structure of the high mountain yellow-spotted ringlet butterfly Erebia manto (Lepidoptera, Satyrinae): a conservation problem

Mountain species have evolved important genetic differentiation due to past climatic fluctuations. The genetic uniqueness of many of these lineages is now at risk due to global warming. Here, we analyse allozyme polymorphisms of 1306 individuals (36 populations) of the mountain butterfly Erebia manto and perform Species Distribution Models (SDMs). As a consensus of analyses, we obtained six most likely genetic clusters: (i) Pyrenees with Massif Central; (ii) Vosges; (iii-v) Alps including the Slovakian Carpathians; (vi) southern Carpathians. The Vosges population showed the strongest genetic split from all other populations, being almost as strong as the split between E. manto and its sister species Erebia eriphyle. The distinctiveness of the Pyrenees-Massif Central group and of the southern Carpathians group from all other groups is also quite high. All three groups are assumed to have survived more than one full glacial-interglacial cycle close to their current distributions with up-hill and down-slope shifts conforming climatic conditions. In contrast with these well-differentiated groups, the three groups present in the Alps and the Slovakian Carpathians show a much shallower genetic structure and thus also should be of a more recent origin. As predicted by our SDM projections, rising temperatures will strongly impact the distribution of E. manto. While the populations in the Alps are predicted to shrink, the survival of the three lineages present here should not be at risk. The situation of the three other lineages is quite different. All models predict the extinction of the Vosges lineage in the wake of global warming, and also the southern Carpathians and Pyrenees-Massif Central lineages might be at high risk to disappear. Thus, albeit global warming will therefore be unlikely to threaten E. manto as a species, an important proportion of the species' intraspecific differentiation and thus uniqueness might be lost.

Effects of inbreeding on fitness-related traits in a small isolated moose population

Inbreeding can affect fitness-related traits at different life history stages and may interact with environmental variation to induce even larger effects. We used genetic parentage assignment based on 22 microsatellite loci to determine a 25 year long pedigree for a newly established island population of moose with 20–40 reproducing individuals annually. We used the pedigree to calculate individual inbreeding coefficients and examined for effects of individual inbreeding (f) and heterozygosity on fitness-related traits. We found negative effects of f on birth date, calf body mass and twinning rate. The relationship between f and calf body mass and twinning rate were found to be separate but weaker after accounting for birth date. We found no support for an inbreeding effect on the age-specific lifetime reproductive success of females. The influence of f on birth date was related to climatic conditions during the spring prior to birth, indicating that calves with a low f were born earlier after a cold spring than calves with high f. In years with a warm spring, calf f did not affect birth date. The results suggest that severe inbreeding in moose has both indirect effects on fitness through delayed birth and lower juvenile body mass, as well as separate direct effects, as there still was a significant relationship between f and twinning rate after accounting for birth date and body mass as calf. Consequently, severe inbreeding as found in the study population may have consequences for population growth and extinction risk.

Past, present and future conservation of the greater one-horned rhinoceros Rhinoceros unicornis in Nepal

Until the early 1980s the only surviving population of the greater one-horned rhinoceros Rhinoceros unicornis in Nepal was in Chitwan National Park. Between 1986 and 2003 87 rhinoceroses from Chitwan were translocated into Bardia National Park and Suklaphanta Wildlife Reserve in the western terai region to establish founder populations and reduce the threat of local extinction from natural catastrophic events, disease and/or poaching. The founder populations increased in number through births but a rise in poaching during the period of civil strife in Nepal during 1996–2006 resulted in a dramatic decline in the populations, including in Chitwan. In 2001 the Terai Arc Landscape programme was initiated to connect 11 protected areas in Nepal and north-west India and facilitate dispersal of megafauna and manage them as metapopulations. Corridors that were restored under the programme and that connect Bardia and Suklaphanta with protected areas in India are now used by the greater one-horned rhinoceros. The successes and failures of the last 2 decades indicate that new paradigms for protecting rhinoceroses within and outside protected areas are needed, especially with reference to managing this species at a landscape scale.

Factors shaping gene flow in red deer (Cervus elaphus) in seminatural landscapes of central Europe

We studied gene flow and connectivity between three subpopulations and nine groups of red deer ( Cervus elaphus L., 1758) occurring in forests in northeastern Poland and western Belarus. The red deer in this region mostly originated from translocated individuals that were introduced primarily in the 19th and 20th centuries. The genetic structure of the population has been identified during the previous study. Using 14 microsatellite loci, we detected 14 first-generation migrants between the three subpopulations and 21 among the nine groups of deer. The number of effective migrants (Nm) was estimated to be 2.5 individuals/generation between the subpopulations and 6.2 individuals/generation between the groups. About 80% of first-generation migrants moved less than 150 km. The gene flow of hinds and stags was similar. A least cost path (LCP) analysis was performed using different habitat types: deciduous and mixed forests, coniferous forests, wetlands, meadows, arable lands, scarce settlements, dense settlements, and waters. No significant barriers to dispersal were detected, but individual dispersal was restricted in space by the significant isolation by distance. The best model, explaining the genetic distance (FST/1 – FST) between the forests, suggested that LCP corridor length limited gene flow and high forest cover within LCP corridors increased gene flow among the forests.

Molecular biogeography of red deer Cervus elaphus from eastern Europe: insights from mitochondrial DNA sequences

European red deer are known to show a conspicuous phylogeographic pattern with three distinct mtDNA lineages (western, eastern and North-African/Sardinian). The western lineage, believed to be indicative of a southwestern glacial refuge in Iberia and southern France, nowadays covers large areas of the continent including the British Isles, Scandinavia and parts of central Europe, while the eastern lineage is primarily found in southeast-central Europe, the Carpathians and the Balkans. However, large parts of central Europe and the whole northeast of the continent were not covered by previous analyses. To close this gap, we produced mtDNA control region sequences from more than 500 red deer from Denmark, Germany, Poland, Lithuania, Belarus, Ukraine and western Russia and combined our data with sequences available from earlier studies to an overall sample size of almost 1,100. Our results show that the western lineage extends far into the European east and is prominent in all eastern countries except for the Polish Carpathians, Ukraine and Russia where only eastern haplotypes occurred. While the latter may actually reflect the natural northward expansion of the eastern lineage after the last ice age, the present distribution of the western lineage in eastern Europe may in large parts be artificial and a result of translocations and reintroduction of red deer into areas where the species became extinct in historical times.

Molecular road ecology: exploring the potential of genetics for investigating transportation impacts on wildlife

Transportation infrastructures such as roads, railroads and canals can have major environmental impacts. Ecological road effects include the destruction and fragmentation of habitat, the interruption of ecological processes and increased erosion and pollution. Growing concern about these ecological road effects has led to the emergence of a new scientific discipline called road ecology. The goal of road ecology is to provide planners with scientific advice on how to avoid, minimize or mitigate negative environmental impacts of transportation. In this review, we explore the potential of molecular genetics to contribute to road ecology. First, we summarize general findings from road ecology and review studies that investigate road effects using genetic data. These studies generally focus only on barrier effects of roads on local genetic diversity and structure and only use a fraction of available molecular approaches. Thus, we propose additional molecular applications that can be used to evaluate road effects across multiple scales and dimensions of the biodiversity hierarchy. Finally, we make recommendations for future research questions and study designs that would advance molecular road ecology. Our review demonstrates that molecular approaches can substantially contribute to road ecology research and that interdisciplinary, long-term collaborations will be particularly important for realizing the full potential of molecular road ecology.