Microsatellite variability of Sardinian pine martens, Martes martes

The pine marten, Martes martes, is a medium-sized terrestrial carnivore associated with woodland habitats of the western Palearctic region. The present distribution area of the species also includes six islands of the western Mediterranean basin. The origin of these insular populations and their taxonomic status are still debated; their molecular characterization appears relevant for conservation purposes. To describe the genetic variability of the pine martens from Sardinia we characterized 40 insular and 14 Italian individuals at seven nuclear microsatellite loci. The identification of private alleles and the calculated F(ST) value of 0.074 revealed some genetic differentiation between the two populations, which accounts for the high percentages of correct allocation (96.39-98.80%) scored by the genotype assignment test. The presence of two distinct clusters corresponding to Sardinia and mainland Italy was further confirmed by the multivariate Factorial Correspondence Analysis of individual genotypes. Moreover, the genome of the Sardinian individuals bore signs of past demographic fluctuations, i.e. the presence of the monomorphic locus Ma-4, a lower allelic richness and a lower number of private alleles, which may derive from the combination of drift, founder effects, and human overexploitation. Anyway, if such events ever affected the Sardinian population, this is likely to have happened in the past since, according to our microsatellite data, the present-day population does not show evidence of recent bottlenecks or inbreeding, the Wilcoxon sign-rank test and the F(IS) index being not statistically significant (both P > 0.05). Based on this genetic evidence, we advance hypotheses about the distinctiveness of the Sardinian population and its significance for taxonomy and conservation.     

Mitochondrial phylogeography and population history of pine martens Martes martes compared with polecats Mustela putorius

The flora and fauna of Europe are linked by a common biogeographic history, most recently the Pleistocene glaciations that restricted the range of most species to southern refugial populations. Changes in population size and migration, as well as selection, have all left a signature on the genetic differentiation. Thus, three paradigms of postglacial recolonization have been described, inferred from the patterns of DNA differentiation. Yet some species, especially wide-ranging carnivores, exhibit little population structuring between the proposed refugia, although relatively few have been studied due to the difficulty of obtaining samples. Therefore, we investigated mitochondrial variation in pine martens, Martes martes, in order to understand the extent to which they were affected by glacial cycles, and compared the results with an analysis of sequences from polecats, Mustela putorius. A general lack of ancient lineages, and a mismatch distribution that is consistent with an expanding population, is evidence that the present-day M. martes and Mu. putorius in central and northern Europe colonized from a single European refugium following a recent glaciation. There has also been interspecific mitochondrial introgression between M. martes and the sable M. zibellina in Fennoscandia.     

Scent marking and social relationships in pine martens (Martes martes)

Scent marking was studied in pine martens (Martes martes) in female-female and male-female pairs. Results show that agonistically dominant individuals generally had higher scent marking frequencies. However, environmental familiarity can modify the social relationship, whatever the previous social experiences, and, consequently, marking activity. Despite important intra-and interindividual variations, the subjects appeared to react to physical and social modifications by an increased marking rate. One factor affecting marking activity in both novel and established pairs was the activity level of the conspecific partner. the data support the hypothesis that pine martens react in the same way to physical and social modifications, but with different response levels. The discussion focuses on possible functions of scent marking. © 1993 Wiley-Liss, Inc.     

Habitat characteristics of Eurasian pine martens Martes martes in an insular Mediterranean environment

Eurasian pine martens are considered habitat specialists, associated primarily with mature stands of mesic mixed wood forest habitats, and avoid areas without overhead cover The species is found throughout the temperate and boreal regions of the continent but on the Mediterranean island of Minorca, introduced pine martens thrive in a competitor- and predator-free environment I test the prediction that because of evolved prey-capture and predator avoidance strategies Minorcan martens should select habitats most similar to temperate and northern parts of their range Scat index routes were used to quantify pine marten habitat selection Marten did not demonstrate any habitat type preferences although observed use of pine forests and coastal shrublands was slighly greater than expected Marten were indifferent to overhead cover whereas mesic sites and areas of tall high shrub density were favored Small mammal trap indices and preferred prey suggested that martens commonly used non-forested areas My results demonstrated that on Minorca pine martens were habitat generalists In the absence of predators open non-forested habitats were equally important to pine marten as were forested ones     

Genetic structure of European pine martens (Martes martes), and evidence for introgression with M. americana in England

European pine martens (Martes martes)were once distributed across much ofwestern Europe. A combination of factors, suchas persecution, trapping, and habitat loss haveled to sharp declines in the species' numbersand range and, as such, local populations havebecome more vulnerable to extinction. Toevaluate the influence of these factors on boththe level of genetic variation and populationstructure, we genotyped pine martens fromacross much of their current distribution. Continental M. martes populations werefound to have a higher level of geneticstructure and lower genetic variation thantheir North American sibling species, M.americana, sampled throughout Canada. Thedifferences among mainland populations of thesespecies may lie in greater levels of habitatfragmentation and persecution experienced byEuropean martens, though it is difficult toexclude more ancient processes such as theinfluence of glaciations. Among islandpopulations of the two species, the Scottishpopulation revealed a similar level ofstructure and variation to the M. a.atrata population of Newfoundland, howeverIreland was more differentiated with lessgenetic variation. Our work usingmicrosatellites also extends previous mtDNAevidence for the presence of M. americanahaplotypes in England, raising the possibilityof hybridization with M. martes. Thesefindings may influence current discussions onthe status of English martens and theappropriateness of proposed re-introductions byrevealing that some indigenous martens persistin England, despite the presence of somepotential hybrids in the region.     

Linking habitat characteristics with genetic diversity of the European pine marten (Martes martes) in France

Although typically considered as a forest specialist species, the European pine marten (Martes martes) is an example of a number of species that have recently been found to also live in fragmented landscapes. Considering that habitat fragmentation and loss is a major threat to the persistence of mammal species in such landscapes, we investigated the association between habitat characteristics and genetic diversity across four pine marten populations occupying contrasting landscapes in France with different degrees of forest availability and fragmentation. Bayesian and multivariate clustering methods evidenced the presence of three genetic clusters and isolation by distance between populations was found at the national scale. We found an overall moderate level of genetic variability, but no evidence of a bottleneck or deficit in heterozygosity in any of the populations. No pattern of isolation by distance was found within the populations, except in the one located in the Pyrenean Mountains which appeared partly isolated from other continental populations and also showed a lower level of genetic diversity. No obvious association between the pattern of genetic variability and the pattern of forested habitat characteristics was found. We discuss the possibility that pine martens show greater behavioural plasticity than typically expected allowing them to adapt to different habitat types.     

Burrowing by translocated boodie (Bettongia lesueur) populations alters soils but has limited effects on vegetation

Digging and burrowing mammals modify soil resources, creating shelter for other animals and influencing vegetation and soil biota. The use of conservation translocations to reinstate the ecosystem functions of digging and burrowing mammals is becoming more common. However, in an increasingly altered world, the roles of translocated populations, and their importance for other species, may be different. Boodies (Bettongia lesueur), a commonly translocated species in Australia, construct extensive warrens, but how their warrens affect soil properties and vegetation communities is unknown. We investigated soil properties, vegetation communities, and novel ecosystem elements (specifically non‐native flora and fauna) on boodie warrens at three translocation sites widely distributed across the species’ former range. We found that soil moisture and most soil nutrients were higher, and soil compaction was lower, on warrens in all sites and habitat types. In contrast, there were few substantial changes to vegetation species richness, cover, composition, or productivity. In one habitat type, the cover of shrubs less than 1 m tall was greater on warrens than control plots. At the two sites where non‐native plants were present, their cover was greater, and they were more commonly found on boodie warrens compared to control plots. Fourteen species of native mammals and reptiles were recorded using the warrens, but, where they occurred, the scat of the non‐native rabbit (Oryctolagus cuniculus) was also more abundant on the warrens. Together, our results suggest that translocated boodie populations may be benefiting both native and non‐native flora and fauna. Translocated boodies, through the construction of their warrens, substantially alter the sites where they are released, but this does not always reflect their historic ecosystem roles.     

Spatio-temporal population genetics of the Danish pine marten (Martes martes)

A spatio-temporal study of genetic variation in the Danish pine marten ( Martes martes ) populations from the Jutland peninsula and from the island of Sealand was performed using 11 microsatellite markers. Samples obtained from 1892 to 2003 were subdivided into historical (prior to 1970) and recent (from 1970) groups. As compared with the historical samples, there was a significant loss of genetic variation in the recent Jutland population, but not in Sealand. Effective population sizes were estimated using Bayesian-based software (TMVP). Historical effective population sizes were 5897 (90% highest probability density, HPD, limits: 1502–6849) in Jutland and 1300 (90% HPD limits: 224–5929) in Sealand, whereas recent effective population sizes were 14.7 (90% HPD limits: 10.9–23.5) in Jutland and 802 (90% HPD limits: 51.8–5510) in Sealand. Significant genetic differentiation ( F _ST) was found between the two historical samples, between the two recent samples, and between the historical and the recent sample in Jutland; whereas the F _ST value between the historical and the recent sample in Sealand was not significant. The significant genetic differentiation between the historical and the recent samples indicates changes in the genetic compositions over time, and the higher F _ST values between the two recent samples, as compared with the two historical samples, indicates that the populations in Sealand and Jutland have drifted apart within a short time span. No deviation from Hardy–Weinberg equilibrium was found within populations, indicating no further substructuring.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 457–464.     

Spring and summer food habits and habitat use of the Europena pine marten (Martes martes) on the island of Micorca, Spain

The food habits and habitat use of pine marten ( Martes martes L.) on the Balearic Island of Mincorca were studied from March-August 1990. In a 28.2 km² area, a series of hiking trails/forest roads were used to collect pine marten faeces bi-monthly and study te species' differential use of habitats. A total of 28 different food items were identified in 723 faeces. Small mammals were the most important food overall, constituting 34% of the volume During March-April, small mammals were the principal food consumed (63% of volume), followed by birds (19%). In May-June, birds were the main food (40%), then small mammals. Plant material and insects were the most important foods in July-August, both made up 68% of the pine marten diet. The abundance of certain foods and the degree of difficulty in obtaining them appear to be important factors that govern pine marten food selection in Minorca. Habitat use was studied along 12 routes totalling 32.6 km. Pine marten showed preference in March-April for Coastal Shrubland habitat, while during May-June they were found most in the Upland Pine type. During July-August, the Upland Pine and Open Pine habitats were most frequented by pine marten. According to bimonthly food habits data, habitat use seems largely determined by the abundance and availability of their prey items in the available habitat types. Martens may concentrate hunting efforts in areas different from when they are not hunting. The Minorcan pine marten differs from continental populations in its wide use of shrublands, in addition to forests.     

Translocations of digging mammals and their potential for ecosystem restoration: a review of goals and monitoring programmes

1. Globally, translocations are commonly used to improve the conservation status of threatened species. There is increasing recognition that translocations of ecosystem engineers also have the potential to restore ecological processes. Digging mammals are often considered to be ecosystem engineers, as their diggings provide shelter for other species and can significantly alter soil properties, with subsequent changes to vegetation.
2. Using Australian species as a case study, we reviewed published and grey literature on digging mammal translocations to determine how often these translocations are conducted to restore ecosystem processes. We documented ecosystem-level monitoring and research efforts, and assessed whether restoration was perceived to be occurring post-release.
3. At least 208 translocations of 24 digging mammal species have been conducted in Australia, with a further 38 planned for the near future. Prior to 2019, only 3% of translocations included a goal relating to the restoration of ecosystem processes associated with digging activities. Nearly a quarter of pre-2019 translocations have been the subject of some form of ecosystem-level monitoring or research, but long-term ecosystem-level monitoring was very rare. In contrast, 74% of the translocations planned for post-2018 include a goal relating to the restoration of ecological processes and most also include plans to conduct ecosystem-level monitoring.
4. Ecosystem restoration was perceived to be occurring for 26% of the pre-2019 translocations. None of the documents we reviewed indicated that ecological degradation had occurred post-translocation, even when declines in other taxa were recorded.
5. The restoration of ecosystem processes is increasingly being identified as a goal for translocation programmes. Where this is the case, we suggest that translocation practitioners include success criteria for the restoration of ecosystem processes, and commit to long-term monitoring designed to detect ecosystem-level effects of translocations.

     

Reintroduction of freshwater macroinvertebrates: challenges and opportunities

Species reintroductions – the translocation of individuals to areas in which a species has been extirpated with the aim of re‐establishing a self‐sustaining population – have become a widespread practice in conservation biology. Reintroduction projects have tended to focus on terrestrial vertebrates and, to a lesser extent, fishes. Much less effort has been devoted to the reintroduction of invertebrates into restored freshwater habitats. Yet, reintroductions may improve restoration outcomes in regions where impoverished regional species pools limit the self‐recolonisation of restored freshwaters. We review the available literature on macroinvertebrate reintroductions, focusing on identifying the intrinsic and extrinsic factors that determine their success or failure. Our study reveals that freshwater macroinvertebrate reintroductions remain rare, are often published in the grey literature and, of the attempts made, approximately one‐third fail. We identify life‐cycle complexity and remaining stressors as the two factors most likely to affect reintroduction success, illustrating the unique challenges of freshwater macroinvertebrate reintroductions. Consideration of these factors by managers during the planning process and proper documentation – even if a project fails – may increase the likelihood of successful outcomes in future reintroduction attempts of freshwater macroinvertebrates.     

Stress and translocation: alterations in the stress physiology of translocated birds

Translocation and reintroduction have become major conservation actions in attempts to create self-sustaining wild populations of threatened species. However, avian translocations have a high failure rate and causes for failure are poorly understood. While ‘stress’ is often cited as an important factor in translocation failure, empirical evidence of physiological stress is lacking. Here we show that experimental translocation leads to changes in the physiological stress response in chukar partridge, Alectoris chukar. We found that capture alone significantly decreased the acute glucocorticoid (corticosterone, CORT) response, but adding exposure to captivity and transport further altered the stress response axis (the hypothalamic–pituitary–adrenal axis) as evident from a decreased sensitivity of the negative feedback system. Animals that were exposed to the entire translocation procedure, in addition to the reduced acute stress response and disrupted negative feedback, had significantly lower baseline CORT concentrations and significantly reduced body weight. These data indicate that translocation alters stress physiology and that chronic stress is potentially a major factor in translocation failure. Under current practices, the restoration of threatened species through translocation may unwittingly depend on the success of chronically stressed individuals. This conclusion emphasizes the need for understanding and alleviating translocation-induced chronic stress in order to use most effectively this important conservation tool.     

Eco‐evolutionary dynamics in restored communities and ecosystems

Recent ecological studies have revealed that rapid evolution within populations can have significant impacts on the ecological dynamics of communities and ecosystems. These eco‐evolutionary dynamics (EED) are likely to have substantial and quantifiable effects in restored habitats over timescales that are relevant for the conservation and restoration of small populations and threatened communities. Restored habitats may serve as “hotspots” for EED due to mismatches between transplanted genotypes and the restored environment, and novel interactions among lineages that do not share a coevolutionary history, both of which can generate strong selection for rapid evolutionary change that has immediate demographic consequences. Rapid evolution that influences population dynamics and community processes is likely to have particularly large effects during the establishment phase of restoration efforts. Finally, restoration activities and their associated long‐term monitoring programs provide outstanding opportunities for using eco‐evolutionary experimental approaches. Results from such studies will address questions about the effects of rapid evolutionary change on the ecological dynamics of populations and interacting species, while simultaneously providing critical, but currently overlooked, information for conservation practices.     

Experimental studies of evolution in guppies: a model for understanding the evolutionary consequences of predator removal in natural communities

Guppies (Poecilia reticulata) in Trinidadian streams are found with a diversity of predators in the lower reaches of streams, but few predators in the headwaters. These differences have caused the adaptive evolution of guppy behaviour, morphology, male colouration and life history. Waterfalls often serve as barriers to the upstream distribution of predators and/or guppies. Such discontinuities make it possible to treat streams like giant test tubes by introducing guppies or predators to small segments of streams from which they were previously excluded. Such experiments enable us to document how fast evolution can occur and the fine spatial scales over which adaptation is possible. They also demonstrate that the role predators play in structuring this ecosystem resembles many others studied from a more purely ecological perspective; in these streams, as elsewhere, predators depress the numbers of individuals in prey species which in turn reduces the effects of the prey species on other trophic levels and hence the structure of the ecosystem. A focus on predators is important in conservation biology because predators are often the organisms that are most susceptible to local extinction. Their selective loss occurs because large predators have been deliberately exterminated and/or are more susceptible to environmental disturbances. Furthermore, we will argue that predator re-introductions might be destabilizing if, in the absence of predators, their prey have evolved in a fashion that makes them highly susceptible to predation, even after time intervals as short as 50-100 years. A better understanding of the evolutionary impacts of top predators will be critical goal for the policy and practice of large carnivore restoration in the future.     

Digging up the dirt: Quantifying the effects on soil of a translocated ecosystem engineer

Digging mammals are often considered ecosystem engineers, as they affect important properties of soils and in turn nutrient exchange, vegetation dynamics and habitat quality. Returning such species, and their functions, to areas from where they have been extirpated could help restore degraded landscapes and is increasingly being trialled as a conservation tool. Studies examining the effects of digging mammals have largely been from arid and semi‐arid environments, with little known about their impacts and importance in mesic systems. To address this knowledge gap, we investigated the ecological role of a recently introduced population of eastern barred bandicoots (Perameles gunnii) on Churchill Island, Victoria, south‐eastern Australia, from which all digging mammals have been lost. We quantified the annual rate of soil turnover by estimating the number of foraging pits bandicoots created in 100‐m² plots over a 24‐h period. Foraging pit counts could not be completed in each season, and the overall turnover estimate assumes that autumn/winter months represent turnover rates for the entire year; however, this is likely to fluctuate between seasons. Ten fresh and ten old pits were compared to paired undug control sites to quantify the effect soil disturbance had on soil hydrophobicity, moisture content and soil strength. Plots contained between zero and 64 new foraging pits each day. We estimated that an individual eastern barred bandicoot digs ~487 (95% CI = 416–526) small foraging pits per night, displacing ~13.15 kg (95% CI = 11.2–14.2 kg) of soil, equating to ~400 kg (95% CI = 341–431 kg) of soil in a winter month. Foraging pits were associated with decreased soil compaction and increased soil moisture along the foraging pit profile. Eastern barred bandicoots likely play an important role in ecosystems through their effects on soil, which adds to an increasing body of knowledge suggesting restoration of ecosystems, via the return of ecosystem engineers and their functions, holds much promise for conserving biodiversity and ecological function.     

Diet, body condition, and reproduction of Eurasian pine martens Mantes martes during cycles in microtine density

Winter diet, body condition, growth, reproduction, and age structure of pine martens Martes martes were studied during cycles in microtine density in south-central Sweden. I analysed 398 scats collected in winters 1988 89 to 1996-97. and 483 carcasses from martens trapped in winters 1989-90 to 1992-93. Microtines were the single most frequent prey category in the winter diet, and the consumption of microtines was correlated with microtine density. In the absence of microtines. pine martens increased the relative consumption of some alternative prey, most notably hares. Among adults, total food consumption, body condition, and reproductive success did not follow microtine density. Among juveniles, there were indications of lower total food consumption, smaller fat deposits, and higher trapping vulnerability, and among juvenile females also of lower body growth, when microtines were scarce. The data were, however, not consistent in this respect. I suggest that pine martens in the southern boreal region do not suffer from food shortage at microtine lows, and accordingly, that the demography of pine martens is independent of microtine cycles.     

Post-release survival of translocated fishers: implications for translocation success

As a vital tool for the conservation of species at risk, translocations are also opportunities to identify factors that influence translocation success. We evaluated factors associated with post-release survival of 90 radio-tracked fishers (Pekania pennanti) translocated from central British Columbia, Canada, to the Olympic Peninsula of Washington, USA, from 2008 to 2011. We hypothesized that the survival of translocated fishers would be affected by the same factors that influence the survival of resident, native fishers (i.e., sex, age, season, body condition), and additional factors that were associated with the translocation process (e.g., duration of captivity, release date, yr of release). Fisher survival was most strongly influenced by translocation year (i.e., release-yr cohort), season, sex, and age class of fisher; whereas duration of captivity, standardized body mass, release date, and number of intact canines did not influence survival. Survival was lowest for fishers released in cohort 2 in 2009 and during the breeding season (Mar–Jun), and was greatest for juveniles and males. When combined across release-year cohorts, year 1 survival rates were greatest for juvenile males followed by juvenile females, adult females, and adult males. Sex and age-related differences in survival of translocated fishers were counter to those commonly reported for established fisher populations, where adult females often have the highest survival rates and juveniles the lowest. Predation (40%) and vehicle strikes (20%) were the most common causes of known mortality among the 24 recovered fishers for which cause of death was determined. We speculate that females face higher risks of mortality in translocated populations because their small size makes them more vulnerable to predation and because adult females in resident populations are less likely than males and juveniles to disperse. Our findings support designing translocations that favor releasing a preponderance of female fishers in recognition of their lower survival rates and to ensure adequate breeders are established in the population, and juvenile and young adult fishers to enhance survival of both sexes. Releases conducted over multiple years will minimize the impact of stochastic annual events that may adversely affect survival in any given year. Persistence, widespread distribution, and documented reproduction of fishers within our study area for ≥6 years following the last releases indicate that survival parameters we measured contributed toward successful population establishment over the short term.     

Giraffe translocations: A review and discussion of considerations

Giraffe populations have declined dramatically in the last three decades. Giraffe translocations are likely to increase as wildlife managers seek to augment or re-establish populations. Currently, formal practical guidance for giraffe translocations is limited. Here, we present a review of translocation guidelines emphasising planning, implementation, monitoring and evaluation, and we review giraffe behaviour and ecology to provide recommendations specific to the translocation of giraffes. We also aim to stimulate discussion about best practices for giraffe translocations and further research into the ethical and practical considerations of moving giraffes.