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Hamadryas baboons, Papio hamadryas, differ from almost all other primate species in that males separate female kin by aggressively coercing females into joining their one-male units. Male behaviour thus appears to be the sole determinant of social structure, shaping patterns of relatedness. However, recent genetic studies have found that female relatedness within one-male units (OMUs) is higher than across OMUs, contrary to expected results of male behaviour. This has caused some researchers to speculate that female hamadryas baboons have some influence over dispersal. In this study, we used an agent-based model to parse how the hamadryas social system influences OMU female relatedness. We hypothesized that (1) the multilevel social structure in hamadryas baboons leads to greater-than-random relatedness in OMUs and that (2) subtle female preference leads to even higher relatedness, similar to the pattern observed in genetic data. Our agent-based model of hamadryas baboon society and dispersal was based on available field data and ran for 150 years in discrete 6-month intervals. To test hypothesis 2, we implemented manipulations mimicking female kin attraction, which increased females’ chances of being transferred into a unit containing closely related females. As output of every simulation, pedigree relatedness of adult female dyads within and across OMUs was calculated. We validated our model by comparing patterns of group size, population size, adult sex ratio and dispersal rates with available field data. The results of our simulations supported both hypotheses. Relatedness within OMUs was slightly higher than across OMUs when females had no influence over dispersal. When we implemented our scenarios of female influence on dispersal, the relatedness within OMUs increased even more, approaching the effect size of genetic data from the field. We conclude that, despite conflicting interests, a combination of male and female behaviour create a complex pattern of gene flow in this unique multilevel social system.

Summary This paper describes advances made to aerial surveys of macropods in New South Wales and Queensland. Regular aerial surveys of macropods across large areas of Australia’s arid and semi-arid rangelands were established as a response to concerns for the species’ conservation. They became integral to the harvest management of the four macropod species – Eastern Grey Kangaroo (Macropus giganteus), Western Grey Kangaroo (M. fuliginosus), Red Kangaroo (Osphranter rufus) and Common Wallaroo (O. robustus). Harvest quotas are set as a proportion of population size, requiring absolute estimates of abundance. Counts were made in strip transects from fixed-wing aircraft, but required correction for animals that are missed. In New South Wales and Queensland, counts are now made using line transect sampling, providing survey-specific correction. Helicopters are used in more rugged and timbered areas and where Common Wallaroo can be more frequently found and harvested. Mark-recapture distance sampling is used in more open country that can be surveyed using fixed-wing aircraft and improves the accuracy of density estimates by accounting for animals missed on the transect line. Macropod populations are likely to be surveyed in the future by airborne imagery and by drones, but the technology needs further development. Spatial models could usefully provide small-scale density estimates and address non-random sampling.

Climate and land management are important environmental drivers that affect the structure of terrestrial plant communities worldwide. Demographic studies allow a mechanistic understanding of the pathways in which environmental factors change population size. Climate and land management might interactively influence vital rates and growth rates of populations, however, demographic studies have not heretofore considered both factors in combination. We used the Global Change Experimental Facility as a platform to study the effect of climate (ambient climate conditions vs. future climate conditions) and land management (sheep grazing vs. mowing) on the demography of the common grass, Bromus erectus growing in semi-natural grassland communities. Using an integral projection model, we found positive population growth rates for B. erectus under all treatment combinations, and an interactive effect of climate and land management. Under ambient climate conditions, population growth of B. erectus was higher in mowed than grazed grassland plots, while population growth rates were similar across both management types under future climatic conditions. This interaction was primarily due to between-treatment changes in seedling recruitment, a vital rate to which the population growth rate is particularly sensitive. The interaction found in this study highlights the importance of considering multiple environmental drivers in demographic studies, to better predict future plant population dynamics and ultimately changes in community structure.

Monitoring the demographics and genetics of reintroduced populations is critical to evaluating reintroduction success, but species ecology and the landscapes that they inhabit often present challenges for accurate assessments. If suitable habitats are restricted to hierarchical dendritic networks, such as river systems, animal movements are typically constrained and may violate assumptions of methods commonly used to estimate demographic parameters. Using genetic detection data collected via fecal sampling at latrines, we demonstrate applicability of the spatial capture–recapture (SCR) network distance function for estimating the size and density of a recently reintroduced North American river otter (Lontra canadensis) population in the Upper Rio Grande River dendritic network in the southwestern United States, and we also evaluated the genetic outcomes of using a small founder group (n = 33 otters) for reintroduction. Estimated population density was 0.23–0.28 otter/km, or 1 otter/3.57–4.35 km, with weak evidence of density increasing with northerly latitude (β = 0.33). Estimated population size was 83–104 total otters in 359 km of riverine dendritic network, which corresponded to average annual exponential population growth of 1.12–1.15/year since reintroduction. Growth was ≥40% lower than most reintroduced river otter populations and strong evidence of a founder effect existed 8–10 years post‐reintroduction, including 13–21% genetic diversity loss, 84%–87% genetic effective population size decline, and rapid divergence from the source population (F ST accumulation = 0.06/generation). Consequently, genetic restoration via translocation of additional otters from other populations may be necessary to mitigate deleterious genetic effects in this small, isolated population. Combined with non‐invasive genetic sampling, the SCR network distance approach is likely widely applicable to demogenetic assessments of both reintroduced and established populations of multiple mustelid species that inhabit aquatic dendritic networks, many of which are regionally or globally imperiled and may warrant reintroduction or augmentation efforts., Monitoring the demographics and genetics of reintroduced populations is critical to evaluating reintroduction success, but species ecology and the landscapes that they inhabit often present challenges for accurate assessments. Using genetic detection data collected via fecal sampling at latrines, we demonstrate applicability of the spatial capture–recapture (SCR) network distance function for estimating the size and density of a recently reintroduced North American river otter (Lontra canadensis) population in the Upper Rio Grande River dendritic network in the southwestern United States, and we also evaluated the genetic outcomes of using a small founder group for reintroduction. Combined with noninvasive genetic sampling, the SCR network distance approach is likely widely applicable to demogenetic assessments of both reintroduced and established populations of multiple mustelid species that inhabit aquatic dendritic networks, many of which are regionally or globally imperiled and may warrant reintroduction or augmentation efforts.

Abstract The Marsh Fritillary butterfly (Euphydryas aurinia) is a Eurasian species which has suffered significant reductions in occurrence and abundance over the past century, particularly across the western side of its range, due to agricultural intensification and habitat loss. This loss has been particularly severe in the UK with extensive localised extinctions. Following sympathetic management, reintroduction was undertaken at four Cumbria (northern UK) sites in 2007 with stock from a captive admixture population descended from Cumbrian and Scottish founders. Annual population monitoring of the reintroductions was undertaken. Nine years post-reintroduction, the level of population genetic variation was assessed using microsatellites. Variation in historical Cumbrian samples was determined using museum samples and Scottish samples from current populations were assayed to characterise natural population variation. Half of the Scottish sites also served as indicators of the alleles present in the founder populations. The genetic contribution of the founder populations allied to population size data allowed patterns of genetic variation to be modelled. Alleles from Cumbrian and Scottish founders are present in the reintroduced populations. The four sites have levels of variation akin to natural populations and exhibit differentiation as predicted by statistical modelling and comparable with natural populations. This suggests that reintroduction following captive breeding can produce self-sustaining populations with natural levels of genetic diversity. These populations appear to be undergoing the same evolutionary dynamics with bottlenecks and drift as natural populations. Implications for insect conservation Reintroduction of captive bred individuals is a viable strategy for producing populations with natural levels of genetic diversity and evolutionary dynamics. Hybridisation of populations on the brink of extinction with those thriving can preserve some of the genetic distinctiveness of the declining population.

The effectiveness of antibiotics against bacterial infections has been declining due to the emergence of resistance. Precisely understanding the response of bacteria to antibiotics is critical to maximizing antibiotic-induced bacterial eradication while minimizing the emergence of antibiotic resistance. Cell-to-cell heterogeneity in antibiotic susceptibility is observed across various bacterial species for a wide range of antibiotics. Heterogeneity in antibiotic susceptibility is not always due to the genetic differences. Rather, it can be caused by non-genetic mechanisms such as stochastic gene expression and biased partitioning upon cell division. Heterogeneous susceptibility leads to the stochastic growth and death of individual cells and stochastic fluctuations in population size. These fluctuations have important implications for the eradication of bacterial populations and the emergence of genotypic resistance.

Vultures are among the most threatened avian taxa in the world. When vultures aggregate in large numbers to feed, poisoned carcasses can extirpate entire populations at once. In the light of shrinking numbers worldwide, restocking and reintroduction projects, where wild or captive-bred vultures are released back into nature, constitute a crucial management tool, successfully implemented in many countries. However, reestablishment of sustainable vulture populations to their historical ranges remains a serious challenge, especially if the threat of poisoning persists, which is usually the case. In this study, we model the outcome of a restocking project where an initial colony is subject to repeated poisoning events. We use as an example the isolated population of the griffon vulture (Gyps fulvus) in Cyprus. Mathematical considerations and model simulations show that the probability of colony persistence depends on the initial population size and the intensity and frequency of the poisoning incidents. This type of scenario creates an Allee effect that requires a colony to exceed a minimum size in order to survive. Also in this scenario, a sequence of small but frequent poisoning episodes is worse on average than a few large and rare ones of the same cumulative mortality. Future population reinforcement efforts for vultures should focus on the release of adult birds in adequate numbers for the successful establishment of sustainable colonies and should involve a reduction in small but persistent sources of mortality such as the poison baiting of small canids that until now has been neglected by conservation scientists.

Geographical variation in the likelihood of biological invasions can be affected by propagule pressure and habitat suitability, which are driven by ecological and social processes. Past studies have empirically quantified the role of drivers by comparing geographical variation in numbers of invading species with variation in candidate factors; however, lack of data has limited empirical studies for individual species. Lymantria dispar (L.), a nonnative forest pest formerly known as gypsy moth, is an exemplar species for exploring invasion drivers because of extensive records on its spread. Since its establishment in eastern United States in 1869, it has been repeatedly introduced into outlying areas, prompting 325 eradication programs from 1972 to 2014. We used these eradication programs as proxies for new establishment events, with the assumption that populations would have established in the absence of eradication treatments. These proxy events were used to quantify the effects of socio-environmental factors on the probability of L. dispar arrival and establishment. Establishment probability was significantly affected by propagule pressure (distance to the previously invaded area, human population size, and the area of source outbreaks) and habitat suitability (climate and availability of host trees). The statistical model developed here can be used to predict invasions and inform surveillance strategies to more efficiently manage these invasions.

Environmental risk assessment of metal mixtures is challenging due to the large number of possible mixtures and interactions. Mixture toxicity data cannot realistically be generated for all relevant scenarios. Therefore, methods for prediction of mixture toxicity from single-metal toxicity data are needed. We tested how well toxicity of Cu-Ni-Zn mixtures to Daphnia magna populations can be predicted based on the Dynamic Energy Budget theory with an individual-based model (DEB-IBM), assuming non-interactivity of metals on the physiological level. We exposed D. magna populations to Cu, Ni, and Zn and their mixture at a fixed concentration ratio. We calibrated the DEB-IBM with single-metal data and generated blind predictions of mixture toxicity (population size over time), with account for uncertainty. We compared the predictive performance of the DEB-IBM with respect to mixture effects on population density and population growth rates with that of two reference models applied on the population level, independent action and concentration addition. Our inferred physiological modes of action (pMoA) differed from literature-reported pMoAs, raising the question of whether this is a result of different model selection approaches, intraspecific variability, or whether different pMoAs might actually drive toxicity in a population context. Observed mixture effects were concentration- and endpoint-dependent. The independent action was overall more accurate than the concentration addition but concentration addition-predicted effects on population growth rate were slightly better. The DEB-IBM most accurately predicted effects on 6-week density, including antagonistic effects at high concentrations, which emerged from non-interactivity at the physiological level. Mixture effects on initial population growth rate appear to be more difficult to predict. To explain why model accuracy is endpoint-dependent, relationships between individual-level and population-level endpoints should be illuminated. Environ Toxicol Chem 2021;40:3034-3048. © 2021 SETAC.

Assessing the risk to threatened species of population decline from anthropogenic disturbances is challenging when there are issues with species identification, and little is known of their biology, distribution, population size, and habitat preference. The bare-rumped sheath-tailed bat (Saccolaimus saccolaimus) is one such species that has a poorly defined distribution over two broad areas of northern Australia. Environmental impact assessments are expected to consider the possibility of its presence in intervening areas outside the known distributions. Our study presents new empirical data that can assist with detection of S. saccolaimus across the entire expanse of northern Australia, provides a critical analysis of acoustics-based identification of the species, and assessed presence within the potentially high value habitat of tall Eucalyptus tetrodonta-dominated forest on the western side of Cape York Peninsula using a combination of trapping and acoustic recordings. Capture of other Saccolaimus species was the greatest of any survey conducted to date in Australia, demonstrating that the capture of these high-flying bat species in tall forest habitats can be relatively effective with mist net arrays hoisted into the tree canopy. In addition, reference echolocation call collections from the focal trapping area plus other locations across northern Australia allowed characterisation and comparison of the calls of most low-frequency-emitting (LFE) echolocating bat species of northern Australia. In addition to separation of species-specific search phase call types using multivariate statistics, a compilation of features from search phase, approach phase and feeding buzz echolocation calls will help distinguish S. saccolaimus from most other LFE species. However, the similarity of the echolocation calls of S. mixtus and S. saccolaimus prevented them from being distinguished from one another. A multi-method approach that emulates the present study and incorporates our recommendations and cautions will lead to robustness in ecological studies and greater clarity in environmental impact assessments.

Cerberiopsis candelabra Vieill. is a long-lived, monocarpic (= semelparous) and mass-flowering rain-forest tree, endemic to New Caledonia. Population size structures suggest establishment has been episodic, followed by a recruitment gap that might signal population decline. Here, we use age structures based on tree rings to better assess population dynamics and persistence, and investigate influences of tree size, age and growth rate on flowering. Age structures of populations surveyed in 2007–2008 were unimodal, with establishment over c. 15–81 y, followed by a recruitment gap of c. 23–79 y. Seedling mortality was generally high. High densities of flowering trees or large-scale exogenous disturbances may be necessary for in-situ regeneration. There was no evidence of a simple flowering threshold: flowering in 2017 occurred across a wide range of tree size, age and growth rate. Instead, evidence suggested that size and age at flowering may vary among plants depending on their growth trajectory. Environmental triggers of flowering were not identified by dating tree establishment, but the last three mass-flowering events occurred in years of tropical cyclones. Regeneration and persistence might be facilitated if large-scale disturbances trigger flowering, improving reproductive efficiency by synchronising flowering and linking reproduction with environmental conditions that enhance seedling recruitment.

The current status of the elasmobranchs’ populations and distribution in the Canary Islands is uncertain. Here we investigate the abundance and distribution patterns of coastal elasmobranchs of Tenerife, with a special attention on the Aetomylaeus bovinus population using a photo-identification methodology. A total of 35 visual surveys were conducted in 5 coastal areas, in which pictures were taken every time an elasmobranch individual was sighted to conduct further biometry analyses. For A. bovinus sightings, pictures were used to identify each individual. Relative abundances and sex-ratios of the elasmobranchs recorded were calculated. The Western Coastline of the island was more diverse, showing 8 species out of the 9-total observed. The photo-identification technique allowed a preliminary estimation of the population size of A. bovinus in El Palmar area with 10 individuals identified and 10 re-sightings over a period of 12 months. This study provides the first relevant information regarding broad distribution, abundance and diversity of coastal elasmobranchs around Tenerife. The study also provides information regarding site fidelity of 3 mature individuals of Aetomylaeus bovinus in the South West area.

Population size, group composition and feeding ecology of the endemic and endangered Black-and-White Colobus Monkey (Colobus guereza gallarum) was investigated in Harenna Forest, South East Ethiopia by using the line-transect method in 10 selected blocks. During the dry and wet seasons, a mean number of 212 and 246 C. g. gallarum individuals was recorded, respectively. Also, the number of groups of the animal was higher in wet (36) than dry (31) season, but statistically insignificant (P= 0.447). Out of the recorded C. g. gallarum, 25.98% were adult males; 32.53% adult females; 14.85% sub-adult male, 11.14% sub-adult female and 15.50% were juveniles/young. Young leaves were the largest (35.1%) contributor to the diet of guereza followed by shoots (22.1%) in both seasons. Other common items were included mature leaves (20.6 %), bark (17.7%), fruit (2.8%) and flower (1.7%). C. g. gallarum were observed feeding on 19 plant species belonging to 12 families. The highest contribution of the diet was from the family Rosaceae (41.67%), while family Fabaceae, Moraceae and Myrsinaceae were contributing 50% of the diet. Schefflera volkensii was the most consumed plant species which accounted for 7.96%, followed by Urera hypselodendron (7.83%) and Dombeya torrida (7.06%). Moreover, C.g.gallarum mainly forage on leaves particularly young leaves, and their foraging activities depend inside the forest. Thus, to maintain sustainable conservation of the endemic C.g.gallarum in the area, their habitats should be properly protected, and appropriate monitoring strategies should be designed.

Reconstructing past events of hybridization and population size changes are required to understand speciation mechanisms and current patterns of genetic diversity, and ultimately contribute to species' conservation. Sea turtles are ancient species currently facing anthropogenic threats including climate change, fisheries, and illegal hunting. Five of the seven extant sea turtle species are known to currently hybridize, especially along the Brazilian coast where some populations can have ~32%-42% of hybrids. Although frequently observed today, it is not clear what role hybridization plays in the evolutionary diversification of this group of reptiles. In this study, we generated whole genome resequencing data of the five globally distributed sea turtle species to estimate a calibrated phylogeny and the population size dynamics, and to understand the role of hybridization in shaping the genomes of these ancient species. Our results reveal discordant species divergence dates between mitochondrial and nuclear genomes, with a high frequency of conflicting trees throughout the nuclear genome suggesting that some sea turtle species frequently hybridized in the past. The reconstruction of the species' demography showed a general decline in effective population sizes with no signs of recovery, except for the leatherback sea turtle. Furthermore, we discuss the influence of reference bias in our estimates. We show long-lasting ancestral gene flow events within Chelonioidea that continued for millions of years after initial divergence. Speciation with gene flow is a common pattern in marine species, and it raises questions whether current hybridization events should be considered as a part of these species' evolutionary history or a conservation issue.

The ability of tree species to adapt to water stress and increased frequency of bark beetle outbreaks with climate change may increase with population size and standing genetic variation, calling into question the resilience of small, rare plant populations. The Torrey pine (Pinus torreyana) is a rare, genetically depauperate conifer that occurs naturally in a mainland and island population in southern California. Due to recent declines in the mainland population coinciding with drought and Ips paraconfusus bark beetle outbreaks, the species would benefit from an assessment of adaptive genetic diversity. Here, we use RNA-Seq to survey gene-coding diversity across 40 individuals to (1) characterize patterns of genetic diversity in the species and (2) test for genetic differentiation between trees that succumbed to beetle attack or survived following an outbreak. Consistent with previous studies, we found few genetic variants, with most SNPs occurring as fixed differences between populations. However, we found structure within the mainland and polymorphisms segregating in both populations. Interestingly, we found differentiation in genotypes between attacked and surviving trees and 11 SNPs associated with survival status, several of which had defense-related functions. While low diversity suggests limited adaptive capacity, genetic associations with survival in functionally relevant genes suggest adaptive potential for bark beetle defense. This initial study prompts future research to explore the genetic basis of putative resistance and suggests conservation efforts should protect surviving genotypes and the full spectrum of genetic diversity across populations to preserve the evolutionary potential of the species.

New Zealand fur seals (Arctocephalus forsteri) are expanding in numbers and distribution throughout New Zealand. The exception is the West Coast of the South Island, where there is documented decli...

Distribution patterns of species are affected by resource availability, dispersal, disturbance and population dynamics. The smaller population size and range of the native Eurasian beaver (Castor fiber) compared to the non-native North American beaver (Castor canadensis) in Finland raise questions on reasons for the slower range expansion of the native species. We compared the population growth rates and the spread of both species from their release sites. We also studied the factors possibly affecting the spread of the Eurasian beaver in South western Finland in more detail. We found that the North American beaver has spread longer distances than the Eurasian beaver, but we did not find evidence for movement barriers constraining the expansion rate of the native species. Lack of high-quality habitats does not seem to constrain the expansion to nearby areas either. Despite this, the Eurasian beaver population has grown to a high density close to its reintroduction site, and it has started to spread to novel areas only recently. We conclude that the expansion of the native beaver in Finland seems to be controlled by factors other than those related to barriers for movement: movement behavior and population dynamics, which require further investigation.

Variation in behavioural traits is especially important in novel habitats where selection forces determine successful colonizers. Prey species must constantly balance the risk versus reward of remaining in an area with threats while gaining possible fitness benefits. Flight initiation distance, the distance at which an animal flees when approached by a human, is a common metric used to assess habituation to stressors and risk behaviour. Here we examine the flight initiation distance of 519 feral pigeons (Columba livia) across New York City, U.S.A. We examined this behavioural response across the metropolitan landscape with respect to multiple urbanization factors related to human activity, the abiotic environment and the ecological community. We used principal component analysis (PCA) to transform landcover characters and then liner models to test various anthropogenic variables including landcover, pedestrian traffic and human population size. We found that flight initiation distance in pigeons decreased with increased human activity (measured by pedestrian traffic and human population size) and more urban landcover (specifically longer road length and greater amounts of impervious surface). We also found that flight initiation distance was shorter in areas with more peregrine falcon, Falco peregrinus, sightings, but longer in areas with more red-tailed hawk, Buteo jamaicensis, sightings. Overall, this research demonstrates that feral pigeon behaviour varies with urbanization, human activity and ecological attributes. Since behavioural changes are often the most rapid phenotypic response to change, this study demonstrates that pigeons are responding to anthropogenic stressors, which may set the stage for adaptive changes.

Waterbird populations in eastern Australia have been declining over the past 35 years primarily due to water resource development and resultant changes to natural river flows and flooding. To mitigate these impacts there is an increased allocation of water for the environment, including waterbird populations. We used population viability models to identify the frequency of breeding events required to reverse the trend and achieve long-term species’ management objectives. We found that the population size of straw-necked ibis was primarily dictated by the frequency of large breeding events and to a lesser extent by adult annual survival and the frequency of small breeding events. We identified combinations of small and large breeding events over the next 10 years required for increased population growth. We also assessed the likelihood of current water management policies increasing populations and thereby reversing the decline in eastern Australia’s waterbird populations.

The Southern Ocean has been disproportionately affected by climate change and is therefore an ideal place to study the influence of changing environmental conditions on ecosystems. Changes in the demography of predator populations are indicators of broader shifts in food web structure, but long‐term data are required to study these effects. Southern elephant seals (Mirounga leonina) from Macquarie Island have consistently decreased in population size while all other major populations across the Southern Ocean have recently stabilized or are increasing. Two long‐term mark‐recapture studies (1956–1967 and 1993–2009) have monitored this population, which provides an opportunity to investigate demographic performance over a range of climatic conditions. Using a 9‐state matrix population model, we estimated climate influences on female survival by incorporating two major climatic indices into our model: The Southern Annular Mode (SAM) and the Southern Oscillation Index (SOI). Our best model included a 1 year lagged effect of SAM and an unlagged SOI as covariates. A positive relationship with SAM1 (lagged) related the previous year's SAM with juvenile survival, potentially due to changes in local prey availability surrounding Macquarie Island. The unlagged SOI had a negative effect on both juvenile and adult seals, indicating that sea ice dynamics and access to foraging grounds on the East Antarctic continental shelf could explain the different contributions of ENSO events on the survival of females in this population., This research investigated the influence of large‐scale climate modes (SAM and SOI) on female southern elephant seal survival (φ) by creating demographic models from historic capture‐mark‐recapture data. Map of the Southern Ocean from Tasmania (top) to East Antarctica and the Ross Sea (bottom) with Macquarie Island location marked by a small circle. Surrounding Antarctica, the Polar Front (blue line), 60th parallel south, (gray circle) and winter sea ice extent (white) are overlaid. Top right: Vegetation map of Macquarie Island (adapted from the Australian Antarctic Data Centre map no. 13106) and stylized illustration of a female southern elephant seal, Mirounga leonina (artwork by: Sophia Volzke).

SummaryThe Great Bustard Otis tarda is a globally threatened species with populations inhabiting the steppe zones of Turkey. In recent decades, its populations in Turkey have suffered severe declines in range and size. Although the remaining populations are in urgent need of protection, there has been no national-scale study on the species since 2009, and huge information gaps remain concerning its range, abundance, and movements in the country. Here, we combined data from five years of fieldwork together with all available sight and literature records to present up-to-date estimates of distribution and population size in Turkey, to better understand its movement patterns, to reveal its recent and historical population changes, and to assess its national extinction risk and threats. We find that the species’ breeding population has shrunk by 20–29% over the last five years, and there are only 559–780 breeding Great Bustards in Turkey distributed in two discrete subpopulations. Comparison with historical records shows that the species’ range has shrunk by at least 60% since the beginning of the 20th century. We suggest possible migratory routes within and through Turkey and that Turkey might have a higher regional importance for the species than previously thought. Illegal hunting, agricultural intensification, shift to irrigated crops, overgrazing, collision with powerlines, and disturbance are the most severe threats to the species in Turkey. Our national Red List assessment yields an Endangered categorisation. Further studies are needed to understand the metapopulation structure and movements of the species and to conserve its remaining populations in Turkey.

English and Welsh red squirrel (Sciurus vulgaris) populations are often small, geographically isolated and particularly vulnerable to stochastic events, such as extirpation due to infectious disease. Immigration or emigration via connected habitat with later re-colonisation may be restricted or not possible and pathogenic disease impact magnified, increasing population loss risk compared to extensive habitat populations. In the United Kingdom (UK), both squirrelpox virus (SQPV) and adenovirus (ADV) infections are major threats to regional in situ conservation and translocation studies. It is important that any amplification of mortality impacts are understood including via population size, isolation and additional threats such as urbanisation. Here, we quantified mortalities between August 2019 and July 2020 in three small isolated English woodland populations and a small woodland fragment on the island of Anglesey, Wales. A cumulative red squirrel population estimate at the four sites during the study was 45–55 animals, with 30 recorded deaths and 15 carcasses recovered for post-mortem examination. Cause of death varied, including trauma, predation, ectoparasite burden, ADV-associated disease and squirrelpox. Negative-stain transmission electron microscopy (TEM) confirmed squirrelpox in four animals, with ADV-associated disease recorded in five others. Polymerase chain reaction (PCR) confirmed asymptomatic ADV infection in three further animals. Surveillance throughout the study revealed red squirrel persistence in each woodland location with grey squirrels (Sciurus carolinensis) recorded at two of four sites. Proactive management action, including red squirrel conservation mitigations have been prepared for each site, with formal red squirrel strategy development for such isolated populations ongoing, via citizen-based action and appropriate analytical support. We recommend analytical disease surveillance and invasive species management continue as central pillars of such conservation efforts.

Declines in the abundance and diversity of insects pose a substantial threat to terrestrial ecosystems worldwide. Yet, identifying the causes of these declines has proved difficult, even for well-studied species like monarch butterflies, whose eastern North American population has decreased markedly over the last three decades. Three hypotheses have been proposed to explain the changes observed in the eastern monarch population: loss of milkweed host plants from increased herbicide use, mortality during autumn migration and/or early-winter resettlement and changes in breeding-season climate. Here, we use a hierarchical modelling approach, combining data from >18,000 systematic surveys to evaluate support for each of these hypotheses over a 25-yr period. Between 2004 and 2018, breeding-season weather was nearly seven times more important than other factors in explaining variation in summer population size, which was positively associated with the size of the subsequent overwintering population. Although data limitations prevent definitive evaluation of the factors governing population size between 1994 and 2003 (the period of the steepest monarch decline coinciding with a widespread increase in herbicide use), breeding-season weather was similarly identified as an important driver of monarch population size. If observed changes in spring and summer climate continue, portions of the current breeding range may become inhospitable for monarchs. Our results highlight the increasingly important contribution of a changing climate to insect declines.

Population monitoring is required to guide conservation programs. We conducted a capture–mark–recapture study of a population of the vulnerable green and golden bell frog (Litoria aurea) at the northern end of its range. Frogs were captured and marked over three breeding seasons (2015/16, 2016/17, 2017/18) in a large coastal lagoon. We aimed to: (1) produce annual estimates of population size to describe population trajectory, and (2) investigate monthly variation in abundance, capture probability, and temporary emigration to understand how these factors change at a finer temporal scale. Frog abundance varied across the three annual breeding seasons: 60–280 adult males, 120–190 adult females, and 90–420 subadults. We infer that the population is stable because adult abundance estimates were higher after 2015/16. Because our study sampled only half the available breeding habitat, the overall population may number 350–850 adults. Our modelling revealed >40 males but

Understanding species’ distribution, population trends, and the significance of threatening processes are central to the effective conservation and management of wildlife. The island state of Tasmania, Australia, is home to two of the three extant subspecies of common wombat Vombatus ursinus ursinus and V. u. tasmaniensis, both endemic to the state. We provide a comprehensive conservation assessment of both subspecies in Tasmania, providing information on distribution and habitat, population trends and incidence of roadkill. Wombats are widespread in Tasmania, occurring in most vegetation communities, but particularly in agricultural areas, dry eucalypt forests and woodlands, and grasslands. Wombat roadkills are widespread along most major roads, with the interaction of traffic speed and wombat density likely to be one of the main causes of wombat roadkill along roads with low traffic volume. Despite this, and other factors that impact wombats including sarcoptic mange and targeted culling, population indices from standardised spotlight surveys have increased by 2.6 times over the past 36 years for V. u. tasmaniensis on mainland Tasmania and by 4.2 times over the past 27 years for V. u. ursinus on Flinders Island. Based on IUCN criteria for distribution extent and population size and trends, neither subspecies qualifies for up-listing to Threatened. Nevertheless, because of risks to wombats (e.g. disease and roadkill) ongoing monitoring and research into effective mitigation is warranted.

Bark beetle outbreaks and forest fires have imposed severe ecological damage and caused billions of dollars in lost resources in recent decades. The impact of such combined disturbances is projected to become more severe, especially as climate change takes its toll on forest ecosystems in the coming years. Here, we investigate the impact of multiple disturbances in a demographically heterogeneous tree population, using an age-structured difference equation model of bark beetle outbreaks and forest fires. We identify two dynamical regimes for beetle and fire dynamics. The model predicts that fire helps dampen beetle outbreaks not only by removing host trees but also by altering the demographic structure of forest stands. We show that a stand thinning protocol, which reduces the population size of the largest few juvenile classes by a small percentage, is able to significantly reduce beetle-induced tree mortality. Our research demonstrates one approach to capturing compound disturbances in a mathematical model. Electronic supplementary material The online version of this article (10.1007/s12080-021-00520-y) contains supplementary material, which is available to authorized users.

Data on species composition and frequency of occurrence of the grenadier anchovies (Coilia) spp. is reported from the Mekong Delta (Vietnam) based on fieldwork materials. Information about two numerous species C. lindmani and C. rebentischii is obtained with respect to the spatial distribution and influence of various ecological factors on their density. Abundance of the Lindman grenadier anchovy C. lindmani is significantly higher in freshwater part of the delta compared to the estuary. The Multi-fingered grenadier anchovy C. rebentischii occurs only inside the estuary ecotone. The article is concerned with the effects of the environmental factors, such as oxygen content in the water, salinity, depth, and character of streambed substrate. No seasonal and year to year variations have been detected in terms of the population size. Some data on the biological characteristics are reported for the first time.

Long‐term population declines have elevated recovery of grassland avifauna to among the highest conservation priorities in North America. Because most of the Great Plains is privately owned, recovery of grassland bird populations depends on voluntary conservation with strong partnerships between private landowners and resource professionals. Despite large areas enrolled in voluntary practices through U.S. Department of Agriculture's Lesser Prairie‐chicken (Tympanuchus pallidicinctus) Initiative (LPCI), the effectiveness of Farm Bill investments for meeting wildlife conservation goals remains an open question. Our objectives were to evaluate extents to which Conservation Reserve Program (CRP) and LPCI‐grazing practices influence population densities of grassland birds; estimate relative contributions of practices to regional bird populations; and evaluate percentages of populations conserved relative to vulnerability of species. We designed a large‐scale impact‐reference study and used the Integrated Monitoring in Bird Conservation Regions program to evaluate bird population targets of the Playa Lakes Joint Venture. We used point transect distance sampling to estimate density and population size for 35 species of grassland birds on private lands enrolled in native or introduced CRP plantings and LPCI‐prescribed grazing. Treatment effects indicated CRP plantings increased densities of three grassland obligates vulnerable to habitat loss, and LPCI grazing increased densities of four species requiring heterogeneity in dense, tall‐grass structure (α = 0.1). Population estimates in 2016 indicated the practices conserved breeding habitat for 4.5 million birds (90% CI: 4.0–5.1), and increased population sizes of 16 species , totaling 1.8 million birds (CI: 1.4–2.4). Conservation practices on private land benefited the most vulnerable grassland obligate species (AICc weight = 0.53). By addressing habitat loss and degradation in agricultural landscapes, conservation on private land provides a solution to declining avifauna of North America and scales up to meet population recovery goals for the most imperiled grassland birds., Article impact statement: Voluntary conservation on private land addressing critical habitat needs provides an emerging solution to the decline of grassland birds.

Shortfalls in our knowledge of the most basic parameters, such as overall range and population size, ensure evidence-based conservation of poorly known or ‘missing’ species is inherently difficult. Often, the only source of such knowledge is anecdotal reports, which are usually considered too unreliable to be of value. Methods that help conservation decision-makers use anecdotal records of poorly known or ‘missing’ species to decide where conservation action should occur, and how urgent that action might be, will support better conservation decisions for those species. Here, we use a Delphi-style process based on expert opinion to assess the largely anecdotal sightings record of the Night Parrot (Pezoporus occidentalis), an endangered species from arid central Australia that underwent a significant decline following the arrival of Europeans. Our results clarify the patterns and possible causes of this decline and subsequent range contraction. We conclude that the species persists in only two broad regions, and is probably extinct throughout much of its former range. Our method is applicable to other poorly known species with a similarly sporadic and largely anecdotal sightings record. This method could be used to clarify the historical and current distribution and status of such species, a critical first step in understanding their conservation requirements.

Research question: Can evidence of trickle-down-effects be observed among youth living in \ud the hometowns of Canadian athletes that competed and/or won medals at the London 2012 \ud Olympic Games?\ud Research methods: Leisure-time physical activity (LTPA) rates of male and female youth \ud were extracted from the Canadian Community Health Survey (n > 1,000,000) for 110 health \ud regions during the pre-Olympic (2009/2010), Olympic (2011/2012), and post-Olympic \ud (2013/2014) year periods. The health regions were treated as panel units and, beyond\ud Canadian athletes and medallists, the panel data analysis incorporated population size and \ud previous Olympic hosting as control variables in the model.\ud Results and Findings: The panel analysis revealed that the number of Canadian athletes \ud representing youths’ hometowns at the London 2012 Olympic Games was negatively \ud associated with LTPA rates when considering the full sample of youth, and male youth in \ud particular. Interestingly however, winning medals (of any colour) was positively associated \ud with hometown LTPA rates among the full sample of youth and male youth. Hometown \ud population size was negatively associated with LTPA rates for the full sample of youth and \ud female youth specifically. Winning a gold medal and hosting previous Olympic/Paralympic \ud Games were not significantly associated with hometown LTPA rates when considering the \ud full sample of youth or male and female youth separately. \ud Implications: Our study demonstrates a need for researchers and sport managers to consider \ud the spatial reach and scope of trick-down-effects beyond that which can occur within a host \ud nation. These effects have the potential to be a global phenomenon.

Expert knowledge is widely used for assessing the conservation status of little-known species. Pterocymbium oceanicum is a large, emergent tree endemic to Fiji. Experts classified the species as ‘Critically Endangered’ (IUCN Red List) in 2016 and estimated the population size at

Birds underlie a predation-starvation risk, and foraging should show a diurnal/circadian pattern. Camera traps were used to study visitation patterns and discovery of a novel food source in woodland birds in SW Germany. A total of 18 species occurred at feeders with nine of them being exploratory species. Great Tits (Parus major) discovered novel food sources first in most instances, and first discoveries occurred on average at 10:38, while it took 97 h for the first detection of the food source. Population size was correlated with discovery. The study supports the predation-starvation risk hypothesis with discovery of food sources in the morning.

Benthic species, though ecologically important, are vulnerable to genetic loss and population size reduction due to impacts from fishing trawls. An assessment of genetic diversity and population structure is therefore needed to assist in a resource management program. To address this issue, the two-spined yellowtail stargazer (Uranoscopus cognatus) was collected within selected locations in the Indo-West Pacific (IWP). The partial mitochondrial DNA cytochrome c oxidase subunit 1 and the nuclear DNA recombination activating gene 1 were sequenced. Genetic diversity analyses revealed that the populations were moderately to highly diversified (haplotype diversity, H = 0.490–0.900, nucleotide diversity, π = 0.0010–0.0034) except sampling station (ST) 1 and 14. The low diversity level, however was apparent only in the matrilineal marker (H = 0.118–0.216; π = 0.0004–0.0008), possibly due to stochastic factors or anthropogenic stressors. Population structure analyses revealed a retention of ancestral polymorphism that was likely due to incomplete lineage sorting in U. cognatus, and prolonged vicariance by the Indo-Pacific Barrier has partitioned them into separate stock units. Population segregation was also shown by the phenotypic divergence in allopatric populations, regarding the premaxillary protrusion, which is possibly associated with the mechanism for upper jaw movement in biomechanical feeding approaches. The moderate genetic diversity estimated for each region, in addition to past population expansion events, indicated that U. cognatus within the IWP was still healthy and abundant (except in ST1 and 14), and two stock units were identified to be subjected to a specific resource management program.

Daily activity in herbivores reflects a balance between finding food and safety. The safety‐in‐numbers theory predicts that living in higher population densities increases safety, which should affect this balance. High‐density populations are thus expected to show a more even distribution of activity—that is, spread—and higher activity levels across the day. We tested these predictions for three ungulate species; red deer (Cervus elaphus), roe deer (Capreolus capreolus), and wild boar (Sus scrofa). We used camera traps to measure the level and spread of activity across ten forest sites at the Veluwe, the Netherlands, that widely range in ungulate density. Food availability and hunting levels were included as covariates. Daily activity was more evenly distributed when population density was higher for all three species. Both deer species showed relatively more feeding activity in broad daylight and wild boar during dusk. Activity level increased with population density only for wild boar. Food availability and hunting showed no correlation with activity patterns. These findings indicate that ungulate activity is to some degree density dependent. However, while these patterns might result from larger populations feeling safer as the safety‐in‐numbers theory states, we cannot rule out that they are the outcome of greater intraspecific competition for food, forcing animals to forage during suboptimal times of the day. Overall, this study demonstrates that wild ungulates adjust their activity spread and level based on their population size., Daily activity of three ungulate species is density dependent across ten temperate forest sites. Activity spread and level increases with ungulate population size. Suggesting that future research should account for population size as a driver of ungulate activity.

In human‐dominated landscapes, connectivity is crucial for maintaining demographically stable mammalian populations. Here, we provide a comprehensive noninvasive genetic study for the brown bear population in the Hellenic Peninsula. We analyze its population structuring and connectivity, estimate its population size throughout its distribution, and describe its phylogeography in detail for the first time. Our results, based on 150 multilocus genotypes and on 244‐bp sequences of the mtDNA control region, show the population is comprised by three highly differentiated genetic clusters, consistent with geographical populations of Pindos, Peristeri, and Rhodope. By detecting two male bears with Rhodopean ancestry in the western demes, we provide strong evidence for the ongoing genetic connectivity of the geographically fragmented eastern and western distributions, which suggests connectivity of the larger East Balkan and Pindos‐Dinara populations. Total effective population size (Ne) was estimated to be 199 individuals, and total combined population size (NC) was 499, with each cluster showing a relatively high level of genetic variability, suggesting that migration has been sufficient to counteract genetic erosion. The mtNDA results were congruent with the microsatellite data, and the three genetic clusters were matched predominantly with an equal number of mtDNA haplotypes that belong to the brown bear Western mitochondrial lineage (Clade 1), with two haplotypes being globally new and endemic. The detection of a fourth haplotype that belongs to the Eastern lineage (Clade 3a1) in three bears from the western distribution places the southernmost secondary contact zone between the Eastern and Western lineages in Greece and generates new hypotheses about postglacial maxima migration routes. This work indicates that the genetic composition and diversity of Europe's low‐latitude fringe population are the outcome of ancient and historical events and highlight its importance for the connectivity and long‐term persistence of the species in the Balkans.

The endangered Moorish tortoise Testudo graeca is the unique terrestrial chelonian species in Northwest Africa. In west-central Morocco, the endemic subspecies, the Souss valley tortoise T. g. soussensis, occupies semi-arid to arid low-quality habitats, and is subject to serious threats. A long-term mark-recapture programme from 2001 to 2012 allowed estimating population size and structure, sex ratio, and survivorship in one of the well-known populations in a degraded and overgrazed arid steppe-land of west-central Morocco. Spring population size considerably decreased to more than half in less than 10 years, with a mean density lower than 3 ind.ha-1 in 2012 compared to its last known density estimated in 2003. In spring 2012, the population structure exhibited an unbalanced male-biased sex ratio (61:39) and a scarcity of juveniles (

The recovery of overexploited populations is likely to reveal behaviours that may have been present prior to harvest but are only now reappearing as the population size increases. The east Australian humpback whale (Megaptera novaeangliae) population (group V, stock E1) has recovered well from past exploitation and is now estimated to be close to the pre-whaling population size. Humpback whales were thought to follow a ‘feast and famine’ model historically, feeding intensively in high-latitude feeding grounds and then fasting while migrating and in calving grounds; however, there is growing evidence that animals may feed outside of known foraging grounds. This short article reports on the first photographically documented evidence of bubble-net feeding by humpback whales in Australian coastal waters (n = 10 groups observed) and provides the first evidence of a second site in the southern hemisphere for the formation of ‘super-groups’ (n = 6 super-groups at discrete locations). The formation of super-groups may be linked to changes in the type or density of prey available, either along the migratory route or in the feeding grounds of the previous summer. It is also possible that the increased population size following recovery make large group sizes while feeding more common. These findings strongly support evidence that feeding behaviour is not restricted to high-latitude foraging grounds in the Southern Ocean, and that prey consumption prior to leaving the coastal waters of Australia may be a significant component of the migratory ecology of this population. Understanding how environmental variation influences the extent to which humpback whales depend on foraging opportunities along their migratory route, and where feeding occurs, will help to predict how future changes in the ocean will influence whale populations. This will also allow for more effective management measures to reduce the impact of threats during this important period of energy consumption.

Aim: Globally distributed pelagic fishes are typified by very low to negligible genetic differentiation at oceanic scales arising from high gene flow and (or) large population sizes. However, genomic approaches employing thousands of loci to characterise genetic variation can illuminate subtle patterns of genetic structure and facilitate demographic inference, such that effects arising from gene flow and population size can be partially decoupled. We used a population genomics approach to identify putative stocks in a circumtropical pelagic fish, wahoo, and to assess global connectivity in this species. Location: Indo-Pacific and Atlantic Oceans. Taxon: Wahoo, Acanthocybium solandri (Cuvier, 1832). Methods: Globally distributed wahoo samples from 11 locations (representing a total of 296 individuals) were sequenced using a pool-seq ezRAD approach to obtain 1289–9825 genome-wide SNP loci per population pair for analyses of genetic structure at a minor allele frequency (MAF) >0.05. Demographic inference using a diffusion approximation method (∂a∂i) was performed using 11,495–12,812 SNPs per population pair at a MAF >0.02. Results: Genetic structure, measured as F , was overall low, suggesting very little heterogeneity amongst sample pairs (pairwise F ≤ 0.021). However, there was a clear signal of regional genetic structuring between ocean basins. A principal coordinate analysis separated samples from the Indo-Pacific with those from the Atlantic and an analysis of molecular variance suggested that ~77% of variation in genetic structure was amongst regions. Our demographic analyses found greater support for models including migration over simple models of isolation. Main conclusions: Our study provides the most thorough genetic investigation of wahoo to date. We provide evidence for global connectivity of wahoo populations over their evolutionary history, but we also provide the first indication of subtle regional structure between the Indo-Pacific and Atlantic Oceans, which occurs against a background of high gene flow. The identification of regional stocks will inform new management strategies and guide future investigations in wahoo, an increasingly important species in global fisheries. ST ST

Understanding how anthropogenic disturbances affect plant–pollinator systems has important implications for the conservation of biodiversity and ecosystem functioning. Previous laboratory studies show that pesticides and pathogens, which have been implicated in the rapid global decline of pollinators over recent years, can impair behavioral processes needed for pollinators to adaptively exploit floral resources and effectively transfer pollen among plants. However, the potential for these sublethal stressor effects on pollinator–plant interactions at the individual level to scale up into changes to the dynamics of wild plant and pollinator populations at the system level remains unclear. We developed an empirically parameterized agent‐based model of a bumblebee pollination system called SimBee to test for effects of stressor‐induced decreases in the memory capacity and information processing speed of individual foragers on bee abundance (scenario 1), plant diversity (scenario 2), and bee–plant system stability (scenario 3) over 20 virtual seasons. Modeling of a simple pollination network of a bumblebee and four co‐flowering bee‐pollinated plant species indicated that bee decline and plant species extinction events could occur when only 25% of the forager population showed cognitive impairment. Higher percentages of impairment caused 50% bee loss in just five virtual seasons and system‐wide extinction events in less than 20 virtual seasons under some conditions. Plant species extinctions occurred regardless of bee population size, indicating that stressor‐induced changes to pollinator behavior alone could drive species loss from plant communities. These findings indicate that sublethal stressor effects on pollinator behavioral mechanisms, although seemingly insignificant at the level of individuals, have the cumulative potential in principle to degrade plant–pollinator species interactions at the system level. Our work highlights the importance of an agent‐based modeling approach for the identification and mitigation of anthropogenic impacts on plant–pollinator systems., Article impact statement: Sublethal effects of pesticides and disease on pollinator foraging behavior threaten the stability of pollination systems.

The Guizhou odorous frog Odorrana kweichowensis is endemic to Guizhou Province, China. In this study, a comparative analysis of the mitochondrial COI and ND2 gene sequences was performed to examine genetic diversity in 109 individuals from ten localities across the geographic range of the species. Haplotype diversity and nucleotide diversity were 0.576 and 0.00055, respectively. Phylogenetic analyses almost nested all haplotypes into one lineage. AMOVA indicated that total variation was mainly derived from variation within individual populations. Neutral tests indicated that a recent expansion occurred in the total population. Fst estimations indicated that genetic divergence was not correlated with geographic distance. Accordingly, the species probably experienced a recent population expansion, and there no obvious population genetic structure is apparent. The findings provide useful information for the conservation of this species.

The seasonal occurrence and temporal sexual segregation of great white sharks Carcharodon carcharias have been widely documented in various temperate and sub-tropical waters across the globe. Yet, there is limited understanding of the relationship between the life stages and habitat use of C. carcharias, particularly in the Southern Cape. In this study, we investigated the population dynamics of C. carcharias in Mossel Bay, South Africa, between 2009 and 2013, using skipper logbooks and citizen research data obtained by a cage-diving vessel. A total of 3064 sharks, ranging in life history stages from young-of-the-year to subadult, were sighted during 573 trips. Juveniles dominated the sightings throughout the study, and there was marked sexual segregation, with females dominating the total sightings of sharks. C. carcharias were most abundant during the cooler, winter season, with females differing in abundance seasonally and males maintaining a low abundance throughout the year but peaking in the winter. In addition, sea surface temperature was the best indicator of C. carcharias presence. Abundance was greatest when vertical water visibility exceeded 3 m, with cloud cover influencing overall abundance negatively. Likely reasoning for the aggregation of C. carcharias in Mossel Bay includes the favourable conditions and abundance of food. Juvenile sharks may also utilise this area as a training ground to learn from larger conspecifics. This research demonstrates that information on population size and structure of C. carcharias can be obtained effectively through a compilation of logbook and citizen science data to assess and identify potential critical habitats in the quest to develop appropriate management strategies. This research also shows value in commercial cage-diving operations deriving international data sets needed to assess global populations of C. carcharias.

Birgus latro, the largest terrestrial arthropod in the world, has undergone a substantial decline globally over the last decades, with only a few healthy populations remaining where they are actively protected. We aimed to quantify demographic and spatio-temporal dynamics of a protected population ofB. latroon Aldabra Atoll (Seychelles). Based on results along 2 transects on the atoll from 2007 to 2016, we calculated an average (±SE) density of 23.7 ± 1.1 ind. ha-1. This suggests a population of around 5000B. latroin the coastal area of Picard Island, which is likely to be an underestimate due to the cryptic nature of the species. The average density within the study area was stable over the study period, and over the yearly cycle, the population exhibited high spatial and temporal variability in count, size and sex ratio and in association with the lunar cycle. Aldabra’sB. latropopulation is male-biased (3:1 male:female) and sexually dimorphic, with males being larger than females. Males and females moult at different times of the year, and the breeding season overlaps with the region’s wet season (December-March) and was in synchrony with the lunar phase.B. latroon Aldabra present colour polymorphism in a 4:1:1 ratio of orange:blue:intermediate (mixture of orange and blue). Results confirm that Aldabra is an important refuge forB. latroand potentially a natural source population for other areas in the region. Similar long-term studies onB. latroare encouraged to improve knowledge on the species and to support conservation actions to halt the species’ decline.

How genetic diversity is maintained within a range of species is one of the crucial pieces of information in species conservation. Although the classical central-marginal hypothesis assumes genetic paucity in peripheral populations, this pattern is not always the case. The semi-shrub Chimaphila umbellata subsp. umbellate, population of which are located in the southernmost part of the subspecies distribution, is considered to be a threatened species in Japan. Thus, this study aimed to examine which populations should be preferentially conserved and if the central-marginal hypothesis can be applied to this case. Genetic diversity was examined in 15 populations of C. umbellata subsp. umbellata in Japan using 16 nuclear simple sequence repeat markers. Overall, the genetic diversity values within the populations did not correlate with the latitude of the population locality, although those of the southern marginal populations tended to be lower than those of populations in other regions. While the populations are genetically differentiated from each other, recent population size declines were only detected in a few cases. Bayesian inference of population structure revealed three genetically distinct groups. An approximate Bayesian computation revealed that these three genetic groups were derived from the ancient population in a recent times. The contribution of each population to total genetic diversity was estimated by removing a given population and recalculating the total genetic diversity. Only one population contributed to both gene diversity and allelic diversity, while several populations contributed to one or the other. Considering genetic diversity and structure, the conservation priority of Japanese populations of C. umbellata to preserve genetic diversity is discussed.

Context Species translocations are used in conservation globally. Although harvest for translocation may have negative impacts on source populations, translocation programs rarely explore ways of minimising those impacts. In fluctuating source populations, harvest timing may affect its impact because population size and trajectory vary among years. Aims We explored whether the timing and scale of harvest can be altered to reduce its impact on a fluctuating source population of Mallee Emu-wrens, Stipiturus mallee; an endangered passerine in south-eastern Australia. Mallee Emu-wren populations fluctuate with ~5–10-year drought–rain cycles. Methods We used population viability analysis (PVA) to compare the impact of five harvest scales (no harvest, 100, 200, 300 or 500 individuals) under three population trajectories (increasing, stable or decreasing) and two initial population sizes (our model-based estimate of the population size and the lower 95% confidence interval of that estimate). To generate a model-based estimate of the population size, we surveyed 540 sites (9 ha), stratified according to environmental variables known to affect Mallee Emu-wren occurrence. We used an information-theoretic approach with N-mixture models to estimate Mallee Emu-wren density, and extrapolated results over all potential habitat. Key Results We estimate that in spring 2019, the source population consisted of 6449 individuals, with a minimum of 1923 individuals (lower 95% confidence interval). Of 48 harvest scenarios, only seven showed no impact of harvest within 5 years (15%). Those seven all had increasing population trajectories and carrying capacity set to equal initial population size. Twenty-six populations showed no impact of harvest within 25 years (54%). These were either increasing populations that had reached carrying capacity or decreasing populations nearing extinction. Conclusions Initial population size, carrying capacity, harvest scale and population trajectory were all determinants of harvest impact. Given the importance of carrying capacity, further research is required to determine its role in the Mallee Emu-wren source population. Implications Harvesting Mallee Emu-wrens after high-rainfall years will have the least impact because source populations are likely to be large with increasing trajectories. For fluctuating source populations, flexibility in the timing of harvest can reduce its impact and should be considered during translocation planning.

Context Despite the importance of buffalos to income and food needs, there has been little attention to the simulation of breeding programs using different strategies in the Iranian buffalo population. Aims The present study aimed to evaluate different breeding strategies in Iranian native buffalo by using stochastic simulation, and to determine the most appropriate strategy for Iranian buffalo breeding. Methods Different breeding scenarios were simulated for sensitivity of outcomes to the nucleus population size and selection design. Two systems of closed and open nucleus breeding schemes were simulated. Three different nucleus sizes, the optimal fraction of nucleus dams born in the base, and the appropriate fraction of base sires born in the nucleus were considered. Four selection designs were considered: random, phenotypic, best linear unbiased prediction (BLUP), and genomic selection. Key results The results indicated that in different population sizes and both open and closed nuclei, the average total genetic value was higher in genomic selection than in other selection designs. The total genetic value was higher in open nucleus than closed nucleus breeding schemes regardless of selection design. The highest mean of total genetic value was estimated at 91.53 in the optimal nucleus size of 15% of base population for the genomic selection approach and the open nucleus breeding system. In all nucleus population sizes, the highest inbreeding was obtained for selection based on BLUP, followed by genomic, phenotype and then random selection. Conclusions Overall, the application of open nucleus breeding schemes along with genomic selection is recommended for improving buffalo productivity. Implications Selection strategies used in Iranian buffaloes have so far been based on phenotypic information; however, obtaining genetic information could improve genetic progress in the Iranian buffalo population.

Little is known about the humpback whales (Megaptera novaeangliae) of the East-African Coast genetic sub-unit (C1). With an estimated population size of 7000 whales, they demonstrate the resilience of the species after commercial whaling caused population numbers to decline drastically. Zavora Bay, Mozambique offers an ideal observation point of the passage of the whales during their annual migration towards the breeding ground of southern Africa and serves as an operating base to monitor this population. This study aimed at identifying the importance of Zavora Bay as part of this breeding ground and the core regions for humpback whale use within the study area. Results showed the waters off the coast of Zavora are actively used for breeding and do not merely serve as passage towards the wintering habitats. A mother-calf pair separation with a preference for shallower waters closer to shore was observed. Besides depth and distance to shore, slope also proved to have a significant influence on the distribution of adult humpback whales. Increased survey effort and more detailed investigation of the threats to humpback whales within the waters of Zavora are recommended.

Geographic variations in the dolphin whistles could be useful in assessing association and isolation among populations. Whistle of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) among the Pearl River Estuary (PRE), Leizhou Bei (LZB) and Sanniang Bay (SNB) populations were investigated. A total of 2850 whistles with legible fundamental contour were extracted and 15 acoustic parameters were measured. Contrary to SNB, PRE and LZB had the same relative proportion of tonal type compositions with flat and sine representing the most frequent types. The generalized linear model analysis showed significant acoustic difference among populations and tonal types. All frequency parameters in SNB were significantly higher than those in PRE and LZB, where no significant variation was observed in most of the parameters either at the population level or within each tonal type. Canonical discriminant functions analysis showed a smaller difference between PRE and LZB than between PRE and SNB and between LZB and SNB. Compared with previous recordings, recent recordings demonstrated a consistent pattern of becoming higher in whistle frequency parameters in both LZB and SNB populations, suggesting that noise pollution in LZB and SNB increasing with time according to the acoustic niche hypothesis. Dolphin whistle's geographic variations could be shaped by the combined function of the geographical barrier function of the Qiongzhou strait and local ambient noise. Considering the isolated condition and the relatively smaller population size of the humpback dolphin in the SNB, more effective and proactive conservation actions should be taken to prevent the extinction of small populations.

Background One of the most challenging tasks in wildlife conservation and management is clarifying which and how external and intrinsic factors influence wildlife demography and long-term viability. The wild population of the Crested Ibis (Nipponia nippon) has recovered to approximately 4400, and several reintroduction programs have been carried out in China, Japan and Korea. Population viability analysis on this endangered species has been limited to the wild population, showing that the long-term population growth is restricted by the carrying capacity and inbreeding. However, gaps in knowledge of the viability of the reintroduced population and its drivers in the release environment impede the identification of the most effective population-level priorities for aiding in species recovery. Methods The field monitoring data were collected from a reintroduced Crested Ibis population in Ningshan, China from 2007 to 2018. An individual-based VORTEX model (Version 10.3.5.0) was used to predict the future viability of the reintroduced population by incorporating adaptive patterns of ibis movement in relation to catastrophe frequency, mortality and sex ratio. Results The reintroduced population in Ningshan County is unlikely to go extinct in the next 50 years. The population size was estimated to be 367, and the population genetic diversity was estimated to be 0.97. Sensitivity analysis showed that population size and extinction probability were dependent on the carrying capacity and sex ratio. The carrying capacity is the main factor accounting for the population size and genetic diversity, while the sex ratio is the primary factor responsible for the population growth trend. Conclusions A viable population of the Crested Ibis can be established according to population viability analysis. Based on our results, conservation management should prioritize a balanced sex ratio, high-quality habitat and low mortality.

Dengue fever, caused by the dengue virus (DENV), is one of the most important reemerging viral diseases transmitted by arthropods worldwide. DENV is maintained in nature in two transmission cycles: urban and sylvatic. The latter has only been recorded in Africa and Asia and involves nonhuman primates as natural hosts, although it has been suggested that other mammals may play a secondary role as potential reservoir host, including bats. The objective of this article is to review the current state of knowledge about DENV-positive bats in the Americas and to determine what ecological and human impact variables could favor DENV infection in bats. We performed a search of published studies on natural and experimental DENV infection in bats. From 1952 to 2019, 14 studies have been carried out (71.4% in the last decade) examining DENV infection in bats in seven countries of the Americas. DENV infection was examined in 1884 bats of 63 species and DENV was detected in 19 of these species. Clench's model estimated that more than 75 species could be carriers of DENV; therefore, considering that at least 350 species of bats are distributed in the Americas, to detect 95% of the DENV-bearing species, it would be necessary to examine about 10,206 bats of ∼287 species that have not been analyzed until 2019. The species with the highest number of positive cases were Molossus sinaloae and Artibeus jamaicensis. Species, colony size, mean annual temperature, mean annual precipitation, human population size, and bat collection site (site inhabited by humans, vegetation cover, and caves) contributed to explain the variation in DENV detection in bats in the Americas. These results provide evidence on the exposure of bats to DENV in different geographic areas of the Americas and a bat sylvatic transmission cycle is very likely to be occurring, where bats may be either accidental hosts, dead-end hosts, or potential reservoir hosts for DENV.