Species Of Conservation Concern Research Articles

Abandonment or biomass production? Phytodiversity responses to land-use changes of semi-natural grasslands in northern Europe

European semi-natural grasslands are hotspots for biodiversity and important for the provisioning of multiple ecosystem services, but their extent has declined considerably during the past century. Increasing demands for agricultural and forest biomass risk causing further loss of grasslands, raising concern about a goal conflict between climate mitigation and biodiversity conservation. This study focused on the loss of semi-natural grasslands in a mixed farm-forest landscape in southern Sweden by comparing plant diversity in grasslands with continuous grazing regimes to recently abandoned grasslands, improved grasslands (sown leys), and afforested grasslands. Compared to actively grazed grasslands, grasslands where grazing had been abandoned showed a lower plant species richness and fewer plant species of conservation concern, but similar species composition. In contrast, both improved and afforested grasslands showed >50 % lower species richness than abandoned and grazed grasslands, with profoundly different species composition. The dissimilarity in plant diversity between sites was primarily driven by the replacement of species (turnover), and trait-based analyses indicated that environmental filtering of light, management, and nutrient requirements of plants shaped the community differences. Furthermore, an increased cover of semi-natural grassland around the sites positively related to plant species richness and diversity, while an increased cropland coverage around the sites showed a negative relationship. Our results emphasize the importance of integrated land-use strategies that prioritize biodiversity conservation in mixed farm-forest landscapes, such as restoration of semi-natural grasslands and strategic planning of biomass production to avoid serious biodiversity losses.

Prioritising areas for conservation within Tropical Important Plant Areas of the British Virgin Islands, Caribbean

Oceanic islands are particularly vulnerable to the global decline of biological diversity, suffering disproportionally large losses of endemic species. A primary tool for mitigating species loss is the establishment of protected area networks. The 2030 Global Biodiversity Framework target calls for the protection of 30% of Earth’s land surface by 2030. This study identifies areas within the Tropical Important Plant Areas network of the British Virgin Islands (BVI), to better inform the expansion of the current protected area network with the objective of conserving the BVI’s unique flora. We identified and applied conservation targets for five threatened habitats and 34 species of conservation concern, including four endemic to the BVI. A total of 5,248 georeferenced plant records for the 34 species collected through decades of collaborative work between the National Parks Trust of the Virgin Islands and the Royal Botanical Gardens, Kew, along with the distribution of five threatened habitats were used within the decision support system MARXAN to identify four spatial portfolios to guide the expansion of the BVI’s current protected area network. Highlighting the need to expand the current (2007–2017) Protected Areas System Plan in the BVI, we found that the current Plan only covers 15% of terrestrial land and does not meet the conservation targets for plants and habitats. The portfolios identified in our analysis efficiently expand the current Protected Areas System Plan to strategically expand coverage for all conservation features, with two main portfolios reaching all defined conservation targets for protection. Notably, to evaluate options not requiring land purchase, we extracted areas within state-owned Crown land from two main identified portfolios and found that the two Crown land-portfolios could protect 28% and 23% of the BVI, respectively, while meeting the targets for most plants of conservation concern. However, to reach 30% land protection and meet the conservation targets for all plant species, including endemics, private land would need to be considered for this inclusion within the protected area network. Our results provide science-based guidance for the selection of candidate protected area expansion sites that include threatened plants and habitats for reaching the 2030 Biodiversity Framework targets. While systematic conservation planning can provide guidance on protected area expansion, it is important to evaluate and prioritise conservation actions, based on multiple solutions and available resources. We recommend similar approaches are applied more broadly throughout the Caribbean and other archipelagos across the world.

Women and urban wildmeat trafficking in the Republic of Congo

As a result of declining biodiversity and increasing rates of urbanization, the illegal urban wildmeat trade is projected to become an integral sector of the wildlife crime industry. Adequate assessment of urban wildmeat trafficking requires investigation into the roles and behaviors of individuals who engage in wildlife crimes. However, akin to much of wildlife crime literature, women's engagement within the urban wildmeat trade have received little investigation. The objectives of our investigation were to (1) explore relationships between women and wildlife products across the supply chain, and (2) determine whether a significant relationship exists between women and specific wildlife products. Through systematic social observations, we evaluate the gendered dimensions of urban wildmeat trafficking in the Republic of Congo between the urban centers of Brazzaville and Pointe-Noire. We place particular emphasis on species of conservation concern, namely great apes, African pangolins, and dwarf crocodiles. Results indicate that there are gendered variations at the species and the geographic level, indicating that women are sourcing and sending their products to different locations than men, and that women are specializing in trade of different species. We attest that urban wildmeat trafficking prevention strategies implement a gender-aware approach due to the unique ways that individuals engage with the industry and how that engagement is gendered.

Influence of temporary emigration on wood turtle (Glyptemys insculpta) detectability, with implications for abundance estimation.

Reliable population estimates are important for making informed management decisions about wildlife species. Standardized survey protocols have been developed for monitoring population trends of the wood turtle (Glyptemys insculpta), a semi-aquatic freshwater turtle species of conservation concern throughout its distribution in east-central North America. The protocols use repeated active search surveys of defined areas, allowing for estimation of survey-specific detection probability (p) and site-specific abundance. These protocols assume population closure within the survey area during the survey period, which is unlikely to be met as wood turtles are a highly mobile species. Additionally, current protocols use a single-pass design that does not allow for separation of availability (pa) and detectability (pd). If there are systematic influences on pa or pd that are not accounted for in the survey design or data analysis, then resulting abundance estimates could be biased. The objectives of this study were to determine if pa is a random process and if pa and pd are influenced by demographic characteristics. We modified the wood turtle survey protocol used in the upper Midwest to include a double-pass design, allowing us to estimate pa and pd using a robust design capture-recapture model. The modified protocol was implemented at 14 wood turtle monitoring sites in Minnesota and Wisconsin between 2017 and 2022. Our results indicated that pa was non-random and that pd increased with turtle carapace length. Our study suggests that model assumptions for current wood turtle population models may be violated, likely resulting in an overestimation of abundance. We discuss possible protocol and modeling modifications that could result in more accurate wood turtle abundance estimates.

Habitat changes explain shifts in bird community composition in abandoned military training areas: Lessons for conservation

Military training areas are important biodiversity refuges and may serve as viable components of regional conservation networks, mainly due to the blocking of ecological succession by the disturbance regime creating a heterogeneous open habitat mosaic hosting many threatened species. However, European armies have undergone downsizing over the past decades and numerous military training areas have been abandoned. The assessment of the consequences of this abandonment for biodiversity would show us whether these abandoned areas still provide conservation benefits. For this purpose, we carried out bird surveys in 30 abandoned military training areas in Czechia. The surveys were performed in two periods (2009 and 2020–2021) to track small-scale changes in land cover and bird abundance after the areas were abandoned in the 1990s. We tested (i) whether changes in bird abundance were related to land cover changes and (ii) whether the observed bird species’ responses to the land cover changes can be explained by species-specific characteristics. Multivariate spatial analyses uncovered significant shifts in land cover composition towards a higher representation of dense shrub, forest and built-up areas at the expense of open areas represented by grassland and sparse shrub. These land cover changes explained a small but significant part of bird abundance variation across the areas. Correspondingly, species benefiting from these land cover changes were associated with dense scrub or forest, such as the Common Chiffchaff, Willow Warbler, or Eurasian Blackcap, whereas species suffering from these changes were associated with grassland, such as the European Stonechat and Eurasian Skylark. Phylogenetically informed interspecific analysis aiming to explain changes in bird abundance between periods confirmed that population declines were linked to open habitat preference, while population increases were linked to the preference for dense shrub and forest. In addition, we found that protected species increased their abundance, most likely due to the existence of conservation management that kept their habitats available. These patterns indicate that military training areas transform toward later successional stages after their abandonment with corresponding changes in bird community composition. However, these changes may not necessarily be negative provided that species of conservation concern enjoy the support of conservation management.

Odonata Assemblages in Urban Semi-Natural Wetlands.

As the human population in urban areas is continuously growing, urbanization is one of the greatest threats to biodiversity. To mitigate the negative effects, the inclusion of blue zones (aquatic habitats) in modern urban development practices is strongly recommended, as they could be beneficial for the local biodiversity conservation. Odonata are a flagship group and are widely used in freshwater conservation as ecological indicators of habitat integrity and health. However, our understanding of their ecological requirements in urban landscapes is not yet complete. Therefore, we analyzed the taxonomic and functional diversity of Odonata in a semi-natural wetland in the Croatian capital. This study was conducted in the summers of 2020 and 2023. Most taxonomic and functional assemblage metrics were comparable between the two main habitat types, anthropogenically disturbed and natural oxbow lakes. However, significant differences were found in relation to the time scale, where most metrics were lower in 2023, indicating the negative impact of extreme climate events (including droughts) that occurred in this region after 2020. With 19 species recorded, our results indicate that semi-natural urban wetlands, especially natural oxbow lakes, have great potential to function as good habitats for Odonata, where even some species of conservation concern were detected. When developing landscape management plans in urban areas, it is essential to consider the importance of habitat heterogeneity in terms of good structure of aquatic macrophytes (presence of submerged, emergent and floating vegetation), which would ensure the most suitable habitat conditions for local Odonata species.

Survival of juvenile greater sage‐grouse in Wyoming

An understanding of vital rate contributions to population growth is necessary for species of conservation concern, such as greater sage‐grouse Centrocercus urophasianus. Sage‐grouse demographic rates are generally well described; however, a notable exception is juvenile survival during the post‐fledging period. We evaluated juvenile survival at two study areas in central and south–central Wyoming. We captured and monitored 124 juvenile sage‐grouse (77 females and 47 males) in 2017–2019 in the central Wyoming study area and 68 (29 females and 39 males) in 2020–2021 in the south–central Wyoming study area. Monthly survival generally increased from September to March in each year and study area. In both study areas, we found no evidence that monthly mortality risk differed between male and female juvenile sage‐grouse. In central Wyoming, seven‐month survival estimates from September to March were 0.28 (85% CI: 0.18–0.44) from 2017–2018, 0.28 (85% CI: 0.20–0.39) from 2018–2019, and 0.43 (85% CI: 0.34–0.55) from 2019–2020. In south‐central Wyoming, survival estimates were 0.34 (85% CI: 0.25–0.47) from 2020–2021 and 0.78 (85% CI: 0.68–0.90) from 2021–2022. Overall, we found evidence that body condition at time of capture and weather (temperature and precipitation) during the pre‐fledging period influenced juvenile mortality risk, but the most supported intrinsic and extrinsic factors varied between study areas. Our results provide additional estimates of juvenile survival that will be useful for understanding sage‐grouse demography. However, the spatial and temporal variation in juvenile survival that we documented should be accounted for when evaluating how management actions may influence sage‐grouse populations.

Large-landscape connectivity models for pond-dwelling species: methods and application to two invasive amphibians of global concern

ContextFunctional connectivity models are essential in identifying major dispersal pathways and developing effective management strategies for expanding populations of invasive alien species. However, the extrapolation of models parameterized within current invasive ranges may not be applicable even to neighbouring areas, if the models are not based on the expected responses of individuals to landscape structure.ObjectivesWe have developed a high-resolution connectivity model for both terrestrial and aquatic habitats using solely potential sources. The model is used here for the invasive, principally-aquatic, African clawed frog Xenopus laevis, which is a species of global concern.MethodsAll ponds were considered as suitable habitats for the African clawed frog. Resistance costs of lotic aquatic and terrestrial landscape features were determined through a combination of remote sensing and laboratory trials. Maximum cumulative resistance values were obtained via capture-mark-recapture surveys, and validation was performed using independently collected presence data. We applied this approach to an invasive population of the American bullfrog, Lithobates catesbeianus, in France to assess its transferability to other pond-dwelling species.ResultsThe model revealed areas of high and low functional connectivity. It primarily identified river networks as major dispersal pathways and pinpointed areas where local connectivity could be disrupted for management purposes.ConclusionOur model predicts how the dispersal of individuals connect suitable lentic habitats, through river networks and different land use types. The approach can be applied to species of conservation concern or interest in pond ecosystems and other wetlands, including aquatic insects, birds and mammals, for which distribution data are limited or challenging to collect. It serves as a valuable tool for forecasting colonization pathways in expanding populations of both native and invasive alien species and for identifying regions suitable for preventive or adaptive control measures.

Population genomics of flat-tailed horned lizards (Phrynosoma mcallii) informs conservation and management across a fragmented Colorado Desert landscape.

Phrynosoma mcallii (flat-tailed horned lizards) is a species of conservation concern in the Colorado Desert of the United States and Mexico. We analysed ddRADseq data from 45 lizards to estimate population structure, infer phylogeny, identify migration barriers, map genetic diversity hotspots, and model demography. We identified the Colorado River as the main geographic feature contributing to population structure, with the populations west of this barrier further subdivided by the Salton Sea. Phylogenetic analysis confirms that northwestern populations are nested within southeastern populations. The best-fit demographic model indicates Pleistocene divergence across the Colorado River, with significant bidirectional gene flow, and a severe Holocene population bottleneck. These patterns suggest that management strategies should focus on maintaining genetic diversity on both sides of the Colorado River and the Salton Sea. We recommend additional lands in the United States and Mexico that should be considered for similar conservation goals as those in the Rangewide Management Strategy. We also recommend periodic rangewide genomic sampling to monitor ongoing attrition of diversity, hybridization, and changing structure due to habitat fragmentation, climate change, and other long-term impacts.

New records and conservation status of tree species from environmental licensing studies in highly human-modified areas in Bahia, northeastern Brazil

Based on fieldwork for licensing environmental impact studies in Bahia, northeastern Brazil, we present new records of five tree species, including two species known only from their type locality. The records mostly originate from highly human-modified areas in Atlantic Forest, which we argue that should not be underestimated by environmental licensing studies. We assess the conservation status of the five species and highlight the importance of using trained botanists for recording species of conservation concern. Our data demonstrate that studies for environmental licensing can contribute knowledge and aid in biodiversity conservation.

An easily implemented single-visit survey method for intermittently available and imperfectly detectable wildlife applied to the Florida east coast diamondback terrapin (Malaclemys terrapin tequesta).

Single-visit surveys of plots are often used for estimating the abundance of species of conservation concern. Less-than-perfect availability and detection of individuals can bias estimates if not properly accounted for. We developed field methods and a Bayesian model that accounts for availability and detection bias during single-visit visual plot surveys. We used simulated data to test the accuracy of the method under a realistic range of generating parameters and applied the method to Florida's east coast diamondback terrapin in the Indian River Lagoon system, where they were formerly common but have declined in recent decades. Simulations demonstrated that the method produces unbiased abundance estimates under a wide range of conditions that can be expected to occur in such surveys. Using terrapins as an example we show how to include covariates and random effects to improve estimates and learn about species-habitat relationships. Our method requires only counting individuals during short replicate surveys rather than keeping track of individual identity and is simple to implement in a variety of point count settings when individuals may be temporarily unavailable for observation. We provide examples in R and JAGS for implementing the model and to simulate and evaluate data to validate the application of the method under other study conditions.

Bird‐habitat associations and local‐scale vegetation structure in lowland brushlands

AbstractBrushlands support a diverse suite of bird species, including species of conservation concern in the western Great Lakes region of central North America. Information on how to effectively manage lowland brushlands for birds and associations between breeding birds and local‐scale vegetation structure and composition is lacking. We surveyed lowland brushlands from 2016–2018 in Minnesota, USA, to assess bird‐habitat associations using avian point‐count surveys and fixed‐radius vegetation plots. We used Poisson regression models to assess the associations between breeding bird species richness, total abundance, and abundance of frequently detected species (using counts as an index for abundance) to woody stem density and height, patchiness of woody stem density, variation of woody stem height, and number of woody plant species. Sedge wrens (Cistothorus stellaris), the most abundant species, were negatively associated with multiple woody plant metrics and positively associated with patchiness. Common yellowthroats (Geothlypis trichas) were the second‐most abundant species and associated with low‐stature woody plants (<1 m based on average heights in study sites). Bird species richness, alder flycatchers (Empidonax alnorum), chestnut‐sided warblers (Setophaga pensylvanica), swamp sparrows (Melospiza georgiana), veeries (Catharus fuscescens), and yellow warblers (Setophaga petechia) increased with woody vegetation height. Chestnut‐sided warbler and Nashville warbler (Leiothlypis ruficapilla) abundances also increased with woody stem density. We suggest that managing lowland brushlands to promote diverse woody plant structure, including tall shrubs and areas with patchy, open herbaceous cover, by implementing temporally and spatially variable disturbance regimes, may benefit bird species that rely on lowland brushlands with a range of vegetation structure requirements.

Long‐term occupancy monitoring reveals value of moderate disturbance for an open‐habitat specialist, the Stephens' kangaroo rat (Dipodomys stephensi)

AbstractFor species of conservation concern, long‐term monitoring is vital to properly characterize changes in population distribution and abundance over time. In addition, long‐term monitoring guides management decisions by informing and evaluating the efficacy of management actions. A long‐term monitoring initiative for the federally threatened Stephens' Kangaroo rat (Dipodomys stephensi, SKR) was established in 2005, across 628 hectares within Marine Corps Base Camp Pendleton (MCBCP), San Diego, California, USA. From 2005 to 2018, we tracked trends in area occupied by SKR, trends in relative SKR densities within occupied habitat, and modeled probabilities of SKR occupancy, colonization, extinction, with habitat, climate, and disturbance covariates. Area occupied by SKR increased almost 2‐fold from 2005 to 2018 on MCBCP, while density in occupied habitat increased almost 3‐fold. Increased area occupied was correlated with increases in estimated density among years, indicating SKR population growth occurs by expansion into suitable habitat patches, as well as increases in numbers within occupied habitat. SKR occupancy was positively associated with gentle slopes (<10%) and moderate open ground (40–80%) and forb cover (>40%). They were more likely to colonize previously unoccupied habitat when there were moderate levels of open ground (40–80%) and low shrub cover (<20%), while more likely to go locally extinct in areas with high slopes (>10%), less open ground (<20%), and increased non‐native grass cover (>40%). Additionally, probabilities of SKR occupancy and colonization were higher in areas with moderate levels of disturbance, which was positively associated with open ground and forb cover. We conclude that long‐term occupancy and density monitoring is effective in informing status and trends of spatially dynamic species and that moderate habitat‐based disturbance is compatible with the management of SKR.

Satellite Remote Sensing Shows Maintenance of Fish Pond Area Improves Persistence of Eurasian Otters in Hong Kong

Urbanization and land cover change are significantly affecting the availability of habitats for wildlife worldwide. However, linking species persistence to large-scale habitat changes is challenging, especially when wildlife monitoring data is lacking. In China, the Eurasian otter (Lutra lutra) is a species of conservation concern and is listed as endangered as a consequence of declining populations across the country. Hong Kong is home to a small population of Eurasian otters, which are primarily restricted to a set of wetlands in the inner Deep Bay area. However, the drivers of their historical distribution changes are largely unknown. We combined otter spraint data from 2018 to 2019 with historical records of otter data spanning 1959–2018 to examine otter habitat preference and changes in their distribution, relating this with land cover changes measured by Landsat-5 and Landsat-8 satellite remote sensing in the past (1986 and 1995) and present (2018) using supervised random forest classification. We found that otters showed habitat preference for fish ponds and watercourses, and persisted in areas where fish pond area was more readily available. We also found no significant effect of the extent of land cover changes on otter persistence, suggesting that the species is resilient to some level of fish pond loss and find value in available terrestrial habitats. Our results demonstrate the utility of relating satellite remote sensing data to species distribution data over decadal time scales and highlight the importance of managing terrestrial and wetland habitats for otters and other key species in increasingly urbanized landscapes.

Range expansion of a declining forest species, the Western Gray Squirrel (Sciurus griseus), into semiarid woodland

Abstract Globally, animals that are range-restricted are frequently becoming species of conservation concern, in part due to competitive exclusion by phylogenetically and ecologically similar species that are more tolerant of human disturbance. However, climate and land use changes to natural landscapes can create pockets of refugia for range-restricted species. Western gray squirrels (Sciurus griseus) are native to the west coast of North America, principally California and western Oregon. Over the past several decades, Western Gray Squirrel populations have declined in human-dominated areas, with increased competition from introduced congeneric species native to eastern North America cited as a primary driver. Despite declines in their established range west of the Pacific Crest in western North America, western gray squirrels are extending their range into the Great Basin, where they were not historically found. Using a network of remote camera traps deployed across the Sierra Nevada–Great Basin ecotone in northwestern Nevada, we detected western gray squirrels across 16 of 100 camera-trapping sites. The majority of detections were located in piñon–juniper woodland, a land cover type not previously occupied by this species. Occupancy modeling revealed that western gray squirrels were equally likely to occur in piñon–juniper woodland compared to mature pine forest that they occupy elsewhere in their range. A species distribution model parameterized with historical gray squirrel observations (pre-1950), indicated increased climatic suitability for the species on the eastern side of the Sierra Nevada in recent decades, which may have facilitated this range expansion. Our findings reveal the potential for species declining in their historical range to colonize novel habitats that become increasingly suitable as a result of human-driven changes to ecosystems.

Life‐history connections to long‐term fish population trends in a species‐rich temperate river

AbstractFishes exhibit a diverse range of traits encompassing life‐history strategies, feeding behaviours and spawning behaviours. These traits mediate fish population responses to changing environmental conditions such as those caused by anthropogenic stressors. The Conasauga River, located in northwestern Georgia and southeastern Tennessee, USA, hosts a diverse assemblage of over 75 species of freshwater fish, some of which are locally or regionally endemic, and many of which are imperilled. Annual monitoring data have shown population declines in multiple fish species of conservation concern in the Conasauga River since at least the 1990s, raising the possibility that other taxa could be declining as well. We quantified temporal changes in fish communities at six shoal sites sampled annually in most years from 1996 to 2022, and asked whether species traits hypothesized to underlie population vulnerability to environmental alteration were correlated with species‐specific trends for 32 taxa. We estimated that total counts of fish in annual samples declined by ~2% per year, although declines were uneven among species and generally greater for less abundant taxa. Tests for species traits corresponding to temporal population trends provided evidence that crevice‐spawning minnows and smaller‐bodied taxa had steeper declines compared with broadcast spawners and larger, longer‐lived, more fecund taxa. Lower abundance, reliance on a particular habitat feature, and life‐history traits that may limit population resilience to disturbance may all prove useful for identifying riverine fishes at particular risk of future population decline.

Differently managed reed beds are home to Coleoptera communities differing in diversity, overall biomass and size

Reed beds can be managed for commercial or conservation purposes, with effects on its inhabitants. In this paper, we assess the effect of management on the reed bed Coleoptera community by investigating reed beds subject to winter cutting, winter harvest, short-term unmanaged (3 years), and long-term unmanaged (25 years). Using pit fall traps, we collected Coleoptera across a summer season to estimate Coleoptera biomass, abundance, size, richness, diversity, and community composition across the four types of management of reed beds. Cutting and harvest both show to increase Coleoptera biomass compared to unmanaged reed beds, with the highest Coleoptera abundance found in the harvested reed bed. The species richness and diversity, on the other hand, peaked in the long-term unmanaged reed bed. Community composition differed between the different management types, and across time. Species of conservation concern were most abundant in recently managed areas. These results have implications for the conservation of the reed bed Coleoptera community. First, to maintain a high Coleoptera diversity, some areas must be left unmanaged. Secondly, to secure habitats for species of conservation concern as well as boost the Coleoptera biomass, frequent management of other areas is advised. This mosaic management pattern will also create the overall most species rich reed bed, as unique Coleoptera communities were found in each management type.

Predicting the spatial distribution of wintering golden eagles to inform full annual cycle conservation in western North America.

Wildlife conservation strategies focused on one season or population segment may fail to adequately protect populations, especially when a species' habitat preferences vary among seasons, age-classes, geographic regions, or other factors. Conservation of golden eagles (Aquila chrysaetos) is an example of such a complex scenario, in which the distribution, habitat use, and migratory strategies of this species of conservation concern vary by age-class, reproductive status, region, and season. Nonetheless, research aimed at mapping priority use areas to inform management of golden eagles in western North America has typically focused on territory-holding adults during the breeding period, largely to the exclusion of other seasons and life-history groups. To support population-wide conservation planning across the full annual cycle for golden eagles, we developed a distribution model for individuals in a season not typically evaluated-winter-and in an area of the interior western U.S. that is a high priority for conservation of the species. We used a large GPS-telemetry dataset and library of environmental variables to develop a machine-learning model to predict spatial variation in the relative intensity of use by golden eagles during winter in Wyoming, USA, and surrounding ecoregions. Based on a rigorous series of evaluations including cross-validation, withheld and independent data, our winter-season model accurately predicted spatial variation in intensity of use by multiple age- and life-history groups of eagles not associated with nesting territories (i.e., all age classes of long-distance migrants, and resident non-adults and adult "floaters", and movements of adult territory holders and their offspring outside their breeding territories). Important predictors in the model were wind and uplift (40.2% contribution), vegetation and landcover (27.9%), topography (14%), climate and weather (9.4%), and ecoregion (8.7%). Predicted areas of high-use winter habitat had relatively low spatial overlap with nesting habitat, suggesting a conservation strategy targeting high-use areas for one season would capture as much as half and as little as one quarter of high-use areas for the other season. The majority of predicted high-use habitat (top 10% quantile) occurred on private lands (55%); lands managed by states and the Bureau of Land Management (BLM) had a lower amount (33%), but higher concentration of high-use habitat than expected for their area (1.5-1.6x). These results will enable those involved in conservation and management of golden eagles in our study region to incorporate spatial prioritization of wintering habitat into their existing regulatory processes, land-use planning tasks, and conservation actions.

A Comparative Multi-Zoo Survey Investigating the Housing and Husbandry of Callimico goeldii

Callimico (Callimico goeldii) are members of the callitrichid family, and a species of conservation concern managed within the European Association of Zoos and Aquaria (EAZA) ex situ program. They benefit from extensive ‘Best Practice’ guidelines developed by the Callitrichid Taxon Advisory Group (TAG), but there are gaps in species-specific knowledge and captive management research. A survey was created to understand and evaluate current housing and husbandry within EAZA collections holding callimico. The questionnaire allowed collation of details including enclosure size along with prevalence of mixed species exhibits, use of UV-B lighting, enclosure complexity and enrichment routines. Responding collections represented 44% of the current callimico holders, with the results allowing comparative analysis of current practice against the guidelines and considering previous research. Significant positive differences were discovered between minimum recommended enclosure dimensions, including total enclosure volume, 32 m3 (p < 0.001, median = 100) and height, 2.5 m (p < 0.001, median = 3) versus EAZA’s minimum recommended dimensions. Encouragingly, no significant difference in complexity was found between on and off exhibit housing, but the results suggest that being housed in a mixed species exhibit offers a more complex environment for callimico (W = 405.5, p < 0.005). The responses revealed overall good practice, although a disparity was noted in the provision of UV-B lighting and the prevalence of enrichment. Observational research focusing on spatial use, preference and behavior is recommended to complement husbandry guidelines. Reference of the survey findings to welfare indicators could determine the effect of current housing and husbandry on callimico welfare.

Monk seals (Monachus monachus) in the Mediterranean Sea: The threat of organochlorine contaminants and polycyclic aromatic hydrocarbons

The Mediterranean monk seal (Monachus monachus) is an emblematic species of conservation concern. Anthropogenic pressures have led to severe population declines and significant fragmentation of the remaining populations. Because of their close relationship with coastal areas, Mediterranean monk seals may be potentially exposed to pollution from agricultural sources, as well as from oil tanker spills. Although monitoring of pollution has long been considered a priority for this species, data on monk seal contamination levels are scarce. In this study, 55 blubber samples of all genders and age classes collected during necropsies (1995–2013) from seals of the Eastern Mediterranean subpopulation were analyzed for organochlorine compounds (OCs), i.e., hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs), and polycyclic aromatic hydrocarbons (PAHs). Overall, PCBs > DDTs ≫ PAHs > HCB in all samples. Results showed a significant downward trend over the 19-year period for DDTs and HCB. No marked pattern was found for PAHs, even though relative abundance of cancerogenic PAH fraction rose in recent years. PCB levels in subadult specimens increased noticeably over time despite worldwide ban. Our findings did not suggest recent releases of DDT or new pesticides (e.g., Dicofol) in the environment, but may indicate an improper disposal of ancient storages of PCBs or a remobilization from reservoirs. OC levels exceeded thresholds that are commonly associated with immunosuppression and reproductive impairment in other pinnipeds. Hence, OCs could be responsible of potential toxicological effects in this subpopulation. This study represents the first report on PAH and one of the few reports on OC bioaccumulation in Mediterranean monk seals. Based on the levels found in the blubber of monk seals from the Eastern Mediterranean, and given the known harmful effects associated to the prolonged exposure to these substances and the reduced long-term expectations of species recovery, regular monitoring is advocated.