Search

To further improve the convergence and solution accuracy of competitive swarm optimizer, a variety of population entropy competitive particle swarm optimization algorithm (CSOPE) is proposed. Firstly, a nonlinear inertia weight adjustment strategy is proposed to balance the global exploration ability and local exploitation ability of particles. Secondly, a population state detection strategy based on entropy model is proposed, which calculates the population entropy by the standardized quartile difference and standardized median difference of the population. The population state is monitored by the difference in entropy values between adjacent generations of the population. When the population is in a convergence state, it uses gray wolf search to exploit winner particle locally to improve the convergence accuracy of the algorithm. The proposed CSOPE algorithm is compared with other 8 optimization algorithms on 21 test functions in CEC2008 and CEC2013, and the experimental results show that the solving accuracy and convergence of the CSOPE algorithm are significantly improved. The CSOPE algorithm is applied to the node localization problem in wireless sensor networks, and the results show that the CSOPE algorithm has high localization accuracy. [ABSTRACT FROM AUTHOR]

Purpose. To carry out a retrospective analysis of changes in the state of the white Dniester crayfish population (Pontastacus eichwaldi bessarabicus Brodsky, 1967) in the Dniester estuary. To provide a description of its abundance and range in this water body. To analyze changes in the main biological characteristics of this species at the population level in the estuary. Methodology. The material for the study was collected from the catches of commerical fishing gear during the crayfish fishery in the Dniester estuary in the period from 2017 to 2021. A complete biological analysis of the obtained material was carried out in the laboratory of the Department of Aquatic Bioresources and Aquaculture of the Odessa State Ecological University (OSEU). The total length of crayfish, their weight, absolute and working fecundity of females, egg diameter, size and weight characteristics of larvae and juveniles were determined. The feeding of crayfish in ontogeny was studied. To assess the reproductive capacity of the crayfish population in the Dniester estuary, we used the coefficient of fecundity preservation Ki calculated on the basis of the obtained data. Statistical data processing was carried out using MS Excel spreadsheets. Findings. In 1950-2021, the range of ​​the population of the Dniester white crayfish in the Dniester estuary decreased from 13 to 7‒8 thousand hectares, and its total stock — up to 200±50 thousand individuals. At the same time, the average density of this crayfish was 17-18 ind. per hectare of the estuary. In recent years, more than 60% of the water area, in which the population of white Dniester crayfish is found in the estuary, is located within the Lower Dniester National Nature Park. In addition, the size and weight of crayfish in the estuary have decreased in recent years. For example, in the 1960s and 1970s, up to 40-45% of individuals were characterized by a length of 13.5-16.5 cm. In 2017, the modal group consisted of individuals with a length of 9-9.5 cm, and in 2019-2021 — 9.6-10.0 cm. The maximum size of crayfish in 2019-2021 was 14.5-15.0 cm (19‒20 cm in 1960-1970s). The reproductive capacity of the population also deteriorated. Absolute and working fecundity decreased. The Ki coefficient for the population of this species in the Dniester estuary in 2017–2018 was 0.63, and in 2020–2021 it was 0.53. This indicates a progressive decrease in the abundance of its population. Originality. For the first time in the last 25‒30 years, an assessment of the current state of the Dniester white crayfish population is given. The analysis of the available data indicates the progressive degradation of the population. A decrease in the range of distribution of this species in the estuary, a decrease in its size, the share of females in the population, and indicators of their fecundity were recorded. A decrease in the coefficient of preservation of fecundity Ki indicates a depressed state of the Dniester white crayfish population in the estuary, which threatens its further degradation. In recent years, catches of white Dniester crayfish in the Dniester estuary have decreased significantly. For example, the catch per fyke net does not exceed 1.0-2.0 kg, and the share of individuals of non-commercial size (up to 10 cm) has increased significantly. Practical Value. The research results allowed: providing an ecological and biological characterization of the state of the Dniester white crayfish population in the Dniester estuary; characterizing changes in the abundance and spatial distribution of crayfish in this water body; highlighting the peculiarities of its biology; determining the strategy of restoration and rational use of the natural population of crayfish, becoming an opportunity during the development of effective methods of its artificial reproduction.

This review aims to illustrate the status and distribution of African elephant in Eastern Africa. The source of data for this review was secondary data including published articles, books, Master theses, PhD dissertations and unpublished literatures. The African elephant (Loxodonta africana) is the largest living terrestrial mammal on the earth and perhaps one of the most intelligent. They are present in 50 countries, 13 of which are in Asia and 37 in Africa. The total estimation of elephant in Africa is 472,269, with 29.1% in the Eastern Africa. In recent report, African elephant in South Africa holds approximately 42%, followed by Eastern Africa with 28%, Central Africa with 25%, and West Africa with 5%. As a result of illegal hunting, African elephant in Eastern Africa declined by 62 percent from 2006 to 2013. Largely attributed decrease in Tanzania. However, the number of African elephants in south Sudan has been increase but there is no longer a resident elephant in Somalia. To sustain African elephant, first and foremost requirement is identifying and assessing its population status and distribution across targeted areas. Therefore, this review is important to realize sustainable management approaches for African elephant in Eastern Africa by understanding their status and distribution.

This review aims to illustrate the status and distribution of African elephant in Eastern Africa. The source of data for this review was secondary data including published articles, books, Master theses, PhD dissertations and unpublished literatures. The African elephant (Loxodonta africana) is the largest living terrestrial mammal on the earth and perhaps one of the most intelligent. They are present in 50 countries, 13 of which are in Asia and 37 in Africa. The total estimation of elephant in Africa is 472,269, with 29.1% in the Eastern Africa. In recent report, African elephant in South Africa holds approximately 42%, followed by Eastern Africa with 28%, Central Africa with 25%, and West Africa with 5%. As a result of illegal hunting, African elephant in Eastern Africa declined by 62 percent from 2006 to 2013. Largely attributed decrease in Tanzania. However, the number of African elephants in south Sudan has been increase but there is no longer a resident elephant in Somalia. To sustain African elephant, first and foremost requirement is identifying and assessing its population status and distribution across targeted areas. Therefore, this review is important to realize sustainable management approaches for African elephant in Eastern Africa by understanding their status and distribution. [ABSTRACT FROM AUTHOR]

We present the main demographic parameters of the Western Siberian pied flycatcher population, nesting in natural habitats, at different stages of population dynamics. The average values, range, boundaries, and direction of changes in the survival of sexually mature individuals, fecundity, and the encounter probability at different ages were analyzed. Using matrix models of population structure and population dynamics, an estimate of the true survival rate of fledglings is given. The range of values of demographic parameters that characterize viable groups of the studied bird species is indicated. [ABSTRACT FROM AUTHOR]

Climate change is poised to exert a significant impact on species distribution in the future, and Taxus cuspidata as an endangered species is no exception. Predicting the potential distribution of T. cuspidata is essential for decision‐makers to develop conservation policies and explicitly implement conservation measures. In this study, a combined model was employed to predict potentially suitable habitats for T. cuspidata based on extant data of T. cuspidata distributions in northeastern China. Our findings suggest that mean diurnal range (bio2) and isothermality (bio3) were identified as dominant factors influencing T. cuspidata distribution. Under future climate scenarios, suitable habitat areas increased only in the SSP126 scenario in the 2070s, declining in all other scenarios. In all climate scenarios, the centroid of suitable habitats ultimately shows a trend in northward movement. Decreases in suitable habitat predominantly occurred in Yanbian Korean Autonomous Prefecture, Baishan city, and Tonghua city. Overall, this study highlights a projected habitat reduction due to climate change. Recommendations entail the strategic establishment of nature reserves and the implementation of initiatives aimed at population replenishment. [ABSTRACT FROM AUTHOR]

Purpose. To carry out a retrospective analysis of changes in the state of the white Dniester crayfish population (Pontastacus eichwaldi bessarabicus Brodsky, 1967) in the Dniester estuary. To provide a description of its abundance and range in this water body. To analyze changes in the main biological characteristics of this species at the population level in the estuary. Methodology. The material for the study was collected from the catches of commerical fishing gear during the crayfish fishery in the Dniester estuary in the period from 2017 to 2021. A complete biological analysis of the obtained material was carried out in the laboratory of the Department of Aquatic Bioresources and Aquaculture of the Odessa State Ecological University (OSEU). The total length of crayfish, their weight, absolute and working fecundity of females, egg diameter, size and weight characteristics of larvae and juveniles were determined. The feeding of crayfish in ontogeny was studied. To assess the reproductive capacity of the crayfish population in the Dniester estuary, we used the coefficient of fecundity preservation Ki calculated on the basis of the obtained data. Statistical data processing was carried out using MS Excel spreadsheets. Findings. In 1950-2021, the range of the population of the Dniester white crayfish in the Dniester estuary decreased from 13 to 7‒8 thousand hectares, and its total stock -- up to 200±50 thousand individuals. At the same time, the average density of this crayfish was 17-18 ind. per hectare of the estuary. In recent years, more than 60% of the water area, in which the population of white Dniester crayfish is found in the estuary, is located within the Lower Dniester National Nature Park. In addition, the size and weight of crayfish in the estuary have decreased in recent years. For example, in the 1960s and 1970s, up to 40-45% of individuals were characterized by a length of 13.5-16.5 cm. In 2017, the modal group consisted of individuals with a length of 9-9.5 cm, and in 2019-2021 -- 9.6-10.0 cm. The maximum size of crayfish in 2019-2021 was 14.5-15.0 cm (19‒20 cm in 1960-1970s). The reproductive capacity of the population also deteriorated. Absolute and working fecundity decreased. The Ki coefficient for the population of this species in the Dniester estuary in 2017-2018 was 0.63, and in 2020-2021 it was 0.53. This indicates a progressive decrease in the abundance of its population. Originality. For the first time in the last 25‒30 years, an assessment of the current state of the Dniester white crayfish population is given. The analysis of the available data indicates the progressive degradation of the population. A decrease in the range of distribution of this species in the estuary, a decrease in its size, the share of females in the population, and indicators of their fecundity were recorded. A decrease in the coefficient of preservation of fecundity Ki indicates a depressed state of the Dniester white crayfish population in the estuary, which threatens its further degradation. In recent years, catches of white Dniester crayfish in the Dniester estuary have decreased significantly. For example, the catch per fyke net does not exceed 1.0-2.0 kg, and the share of individuals of non-commercial size (up to 10 cm) has increased significantly. Practical Value. The research results allowed: providing an ecological and biological characterization of the state of the Dniester white crayfish population in the Dniester estuary; characterizing changes in the abundance and spatial distribution of crayfish in this water body; highlighting the peculiarities of its biology; determining the strategy of restoration and rational use of the natural population of crayfish, becoming an opportunity during the development of effective methods of its artificial reproduction. [ABSTRACT FROM AUTHOR]

Taxus cuspidata is listed as a first-class national key protected plant in the northeast region, with scarce individuals in the wild and significant conservation value. We conducted a systematic field survey to explore the population structure and dynamic characteristics of T. cuspidata in the Baishilazi National Nature Reserve. A total of 313 T. cuspidata were recorded, displaying a spatially clustered distribution. Young individuals made up 33 % of the population, and the population's diameter class structure indicated a decreasing trend in population size. The population's survival curve closely resembled the Deevey-II type. These results suggest that the proportion of young individuals and strong potential for self-renewal. Geographic analysis revealed that north-facing slopes with moderate gradients were the primary habitat for T. cuspidata in the reserve. Interspecific analysis identified Acer ukurunduense and A. komarovii as the species with the highest interspecific associations with T. cuspidata. The population is projected to continue growing. The nature reserve is effectively fostering the natural renewal and recovery of T. cuspidata populations. These findings offer valuable insights for the conservation management of T. cuspidata in Baishilazi National Nature Reserve, supporting the sustainable development of endangered species populations.

Common hippopotamuses (Hippopotamus amphibious) are among the top five herbivorous animals in Africa. Despite being listed as a vulnerable species by the International Union for Conservation of Nature, they are a common mammal in Ethiopia's protected areas, lakes, rivers, and marshes. However, there is insufficient data to evaluate status of the population and habitat compatibility across the most of the country. The aim of this research was to ascertain the population size of hippos and the suitability of its habitat in the Dhidhessa Wildlife Sanctuary (DWS) in southwest Ethiopia. The study was conducted between 2021 and 2022. To estimate the population size, the total count procedures were employed. The adaptability of each habitat for hippos was determined using the multi-ring buffer analysis in Arc GIS 10.2. A total of 231 and 133 hippos were observed during both the dry and wet seasons, respectively. Of the surveyed individuals, 62.08 % were adults, 20.88 % were under-adults, and 17 % were young. More hippos (45.1 %) were observed in the savanna grassland during the rainy season. Subsequently, the hippos (50.6 %) relocated to the riverine forest in the dry season. Thus, the habitats in DWS and their environs were determined to range from most suitable to unsuitable for hippos. The results showed that 58.31 % of the regions were unsuitable, 18.49 % were moderately suitable, and 23.18 % were highly suitable for hippos grazing. 7.95 % of the research area slope was suitable, 26.32 % moderate and 65.72 % not suitable and 19.8 % was considered most suitable for human interference, 46.3 % was severely disturbed, and 33.9 % was moderately affected. Based on the current investigation, it has been determined that human interference in hippos' habitats is significant. In order to protect the hippos' habitats from excessive human activities and their impacts, a buffer should be created around the DWS area.

Abstract Flying foxes of the genus Pteropus, especially those inhabiting islands, face increasing pressure from anthropogenic threats. A first step to implementing effective conservation actions is to establish monitoring projects to understand a species’ population status and trend. Pteropus species are highly affected by seasonality which further requires regular, repeated, and long-term data to understand population trends, and reactions to severe weather events. In the present case study, a regular, bi-annual population census was implemented on Comoros between 2016 and 2023 for the highly threatened Livingstone’s fruit bat, Pteropus livingstonii, and compared the results of standardized monitoring to historical population data. Seasonality had a large impact on the number of bats found at roost sites, with more bats present in the wet season, but the data over the past eight years revealed no significant in- or decrease in the number of bats counted on the island Anjouan. We estimated around 1,200–1,500 bats on Anjouan and 300–400 bats on Mohéli, and found that landcover type has no measurable effect on population distribution at roost sites. Our study highlights the need for long-term surveys to understand past population trends and that single counts are not sufficient to draw final conclusions of a species’ status.

Galicia became a part of the Austro-Hungarian Empire after the first partition of the Polish- Lithuanian Commonwealth and remained within its borders for almost a century and a half. The new territory, which was densely populated by representatives of the Ukrainian and Polish peoples, formed a single administrative-territorial unit. The economic situation of the region and the status of the population, primarily peasants, could not be considered satisfactory, although it slightly improved during the period of enlightened absolutism. After the revolution, the state apparatus of the empire was modernized, the secret council and the court chancellery were abolished. The central government was further formed by ministries. Later, the country embarked on the path of constitutional development, a basic law of the state was adopted, censorship and serfdom were abolished. The development of the Austrian state from absolute monarchy to a monarchy with certain elements of constitutionalism occurred gradually. Each stage was characterized by partial changes in legislation, the political course of the country, and changes in the state apparatus of the country. All these changes to some extent influenced the situation of the Ukrainian population of Galicia. This time coincided with the European «Springtime of Nations.» The coincidence of historical circumstances allowed a part of the Ukrainian people, under relatively comfortable conditions (compared to the part of the Ukrainian people living in the territories that were part of the Russian Empire), to raise not only social, economic, and political issues but also national issues in the conditions of the revolutionary movement. Austria, remaining an absolute monarchy, carried out a series of liberal reforms, including the abolition of personal dependence of peasants from landlords (end of the 18th century) and later serfdom (mid-19th century), and guaranteed certain basic freedoms to citizens: personal (such as personal inviolability), political (voting rights), and so on. The method of building management bodies, the model of resolving social conflicts in the Austro- Hungarian monarchy influenced the development of the Ukrainian idea in Galicia, contributed to the education of a national elite, which actively participated in the development of a modern Ukrainian state and rights at the beginning of the 20th century. [ABSTRACT FROM AUTHOR]

The African blackspot shark Carcharhinus humani (until now commonly known as Human's whaler shark) is a small-sized requiem shark (family Carcharhinidae) found in tropical coastal waters of the western Indian Ocean as far south as Port St Johns on the east coast of South Africa. It was only recently recognised as being distinct from the blackspot shark C. sealei, which occurs elsewhere in the Indo-Pacific. This study utilised four datasets to investigate the movements, temporal and geographic distributions, life history and population status of this species in South African waters. The recapture of eight individuals of 294 that were tagged by shore anglers revealed an average distance moved of 33 km (range 1–192 km). Competitive shore anglers caught an average of 39 C. humani per annum along the entire KwaZulu-Natal (KZN) coast, with no marked trend in catch rate over time. Catches in the KZN bather protection programme were extremely low but included 30 pregnant females which displayed a highly seasonal pattern of embryo development. Sightings of C. humani on stereo baited remote underwater video systems (stereo-BRUVS) in the iSimangaliso Marine Protected Area were dominated by females (7.7:1) and were mostly in deeper water of 26–35 m. In all datasets most of the individuals were mature and were present year-round, but with a clear peak in summer and autumn, especially in the catches taken by shore anglers. Competitive shore-angling catch data were used to conduct a risk assessment for the South African population, and, based on values of probability of encounter, the sampled population satisfies the IUCN Red List criteria for Least Concern. [ABSTRACT FROM AUTHOR]

Abstract Climate change is poised to exert a significant impact on species distribution in the future, and Taxus cuspidata as an endangered species is no exception. Predicting the potential distribution of T. cuspidata is essential for decision‐makers to develop conservation policies and explicitly implement conservation measures. In this study, a combined model was employed to predict potentially suitable habitats for T. cuspidata based on extant data of T. cuspidata distributions in northeastern China. Our findings suggest that mean diurnal range (bio2) and isothermality (bio3) were identified as dominant factors influencing T. cuspidata distribution. Under future climate scenarios, suitable habitat areas increased only in the SSP126 scenario in the 2070s, declining in all other scenarios. In all climate scenarios, the centroid of suitable habitats ultimately shows a trend in northward movement. Decreases in suitable habitat predominantly occurred in Yanbian Korean Autonomous Prefecture, Baishan city, and Tonghua city. Overall, this study highlights a projected habitat reduction due to climate change. Recommendations entail the strategic establishment of nature reserves and the implementation of initiatives aimed at population replenishment.

The purple sea urchin (Heliocidaris crassispina) is one of the main drivers of ecosystem dynamics, and its reproductive cycle plays an important role in population structure and size variability. In this study, we analyzed the population structure, gonadal developmental characteristics, reproductive cycle and other factors influencing wild purple sea urchins from December 2021 to November 2022 in Daya Bay, Guangdong, China. The results showed that purple sea urchins showed an allometric growth pattern, there were obvious seasonal variations in the population size, and fishing pressure reduced the sea urchin populations; two-factor analysis of variance (ANOVA) and correlation analyses showed negative correlations between month (M), test diameter (TD), weight (W) and gonadal index (GI) (P> 0.01), and a positive correlation between TD, weight (W), and GI (P<0.01); the gonadal development process can be divided into recovery, growth, prematuration, maturation, and late discharge, with almost synchronous development of male and female gametes; the spawning period is from April to November, which is longer than in the temperate zones, showing two spawning peaks in April and August. The time of spawning is influenced by temperature and food. Data on the breeding cycle of sea urchins in Daya Bay were obtained in this study. This information can offer theoretical assistance in the preservation and management of both artificial nurseries and wild resources. [ABSTRACT FROM AUTHOR]

The article examines the diversity and population status of wild edible plants in the Kinnaur District of Himachal Pradesh, India. It found a total of 115 plant species, with 91 of these species being used for various edible purposes by the local people. The study highlights the importance of public awareness and community-based management to protect and preserve wild edible plant species in the region. The document provides a list of wild edible plant species found in the fringe forest areas of Himachal Pradesh, along with information on their uses, density, frequency, and importance value index. The research emphasizes the need for further research on the nutritional profiles and processing methods of these plants and calls for their inclusion in future forestry and rural plantation programs. Additionally, the articles explore the utilization of wild edible plants by indigenous communities in various districts of Himachal Pradesh, highlighting their importance in providing nutritional support and offering insights into traditional knowledge and practices. [Extracted from the article]

The Chinkara gazelle (Gazella bennettii), an endangered species, faces a serious threat from anthropogenic activities and climate change. In Balochistan, climate change and drought have created extremely challenging circumstances for its survival. The population status of many species cannot be determined due to a lack of data. If the current situation persists, there is a high risk of extinction for this species in its natural habitat. The purpose of this study was to examine the population dynamics and distribution patterns of Chinkara gazelle in the Khuzdar and Lasbela districts of Balochistan, Pakistan. The study covered an area of approximately 45,123.97 km² and involved a double-observer survey at six sites from 2019 to 2022, using the BBRecapture package in the R programming language. The study detected a decreasing population trend in the Chinkara population over a four-year period. A population of 700, 683, 613 and 583 individuals were observed in 2019, 2020, 2021 and 2022, respectively. Rocky shrub land consistently recorded the highest number of chinkara sightings among various habitats. This study provides valuable information about the Chinkara gazelle population, including population trends, gender ratios, habitat preferences, and density. The findings contribute significantly to our understanding of the species and will be used to develop local-level conservation initiatives. [ABSTRACT FROM AUTHOR]

This article describes the status of the Caucasian rapid racerunner (Eremias velox caucasica Lantz, 1928) population on the Sarykum sand massif. Data collected on its sex-age structure in the first decade of May 2022 were analyzed. Morphometric diagrams based on body length measurements (mm) were built. The results obtained show that the population consists of immature specimens and mature males and females. Adult animals can be divided into two age groups, namely, lizards aged two years and three years or more. The core of the population is made up of immature and two-year-old males and females. Sexual dimorphism related to body length was reliably determined by the nonparametric Mann–Whitney test: males turned out to be larger than females. Although the population is generally stable, it is still negatively affected by the recreational load on the Sarykum territory and the sand overgrowth. These two factors lead to changes in the biotope inhabited by E. v. caucasica. Therefore, it is important to carefully monitor the population of E. v. caucasica on the Sarykum sand massif as this species is listed in the Red Book of the Republic of Dagestan and other southern regions of Russia.

Vultures are vital scavengers that maintain ecological balance by feeding on carcasses. Among the nine vulture species in India, four are categorised as 'Critically Endangered', one as 'Endangered', three as 'Near Threatened', and one as 'Least Concern' as per the IUCN Red List. The vultures have experienced a global decline, while in India, majorly due to the use of diclofenac, a non-steroidal antiinflammatory drug (NSAID). A review of all available literature on vultures from 1838 to December 2022 and extracting of all sight records from eBird to understand their status, occurrence, and distribution for the Indian state of Karnataka. The study reveals a total of seven vulture species recorded from the state, of them, one was misidentified, two are vagrants, and the other four species, namely Egyptian Vulture, White-rumped Vulture, Indian Vulture, and Red-headed Vulture, are residents. The resident vulture population in the state is experiencing a consistent decrease and has been confined in recent years to in and around Bandipur and Nagarahole tiger reserves, while Egyptian Vulture is mostly observed in human-inhabited areas. In contrast to the gradual recovery of the Gyps vulture population across the country, the population in the Ramadevarabetta Vulture Sanctuary remains relatively low or decreasing. Periodic systematic population assessments and monitoring of nest sites, evaluating breeding patterns, and ensuring the availability of undisturbed carcasses for vultures to feed on are suggested. [ABSTRACT FROM AUTHOR]

Freshwater systems have experienced greater biodiversity loss than any other systems on Earth. The Hellbender Cryptobranchus alleganiensis (Daudin, 1803), a fully aquatic salamander species endemic to streams and rivers across the Midwestern and Eastern United States, has experienced drastic declines due to habitat degradation, accelerated sedimentation, aquatic contaminants, and infectious diseases. Although declining water quality is often suggested as a major contributing factor to Hellbender population declines, few studies have evaluated the effects of land use on water quality and Hellbender population status across multiple watersheds and ecoregions. In this study, we sought to understand the relationships between Hellbender population declines with both anthropogenic land use and water quality. We sampled 30 stream sites across a gradient of land use and Hellbender population status in Tennessee and North Carolina, USA, to evaluate relationships between Hellbender populations, water quality, and concentrations of heavy metals and the herbicides glyphosate and atrazine, the latter which we measured via a novel passive sampling technique. We found ecoregion-level differences in atrazine, Cd, pH, and conductivity, with the Interior Plateau ecoregion having the greatest variance in water-quality measurements. Although % watershed development was not different among ecoregions given the sites evaluated, Blue Ridge watersheds were overall less developed than watersheds in the Interior Plateau. We also found relationships between declining Hellbender population status and both increased watershed development and declining estimates of water quality, suggesting that increased anthropogenic watershed disturbance can lead to water-quality declines that can negatively affect the species. Because this research focused on assessing the prevalence of commonly encountered aquatic contaminants, our results and study design are applicable to lotic habitats within the evaluated ecoregions and similar habitats throughout the geographic range of the Hellbender. Our study highlights parameters that should be considered when investigating the effect of anthropogenic disturbance and declining water quality on Hellbender population status and emphasizes the importance of effective land management strategies that reduce anthropogenic effects to freshwater systems. [ABSTRACT FROM AUTHOR]

The demand for comprehensive biodiversity assessments is increasing through the implementation of the ecosystem-based approach to management (EBM) of marine resources. Regional sea conventions such as the Oslo-Paris Commission (OSPAR) strive to implement EBM by developing an extensive status assessment program for the marine environment. Demersal fish communities are one ecosystem feature assessed by OSPAR through several ecological indicators. One of these indicators assesses the recovery in the population abundance of sensitive fish species, which was initially developed to report on the status of the sensitive fish community as a whole. However, for national reporting obligations, contracting parties of OSPAR (particularly for EU member states reporting to the Marine Strategy Framework Directive) prefer to have assessments for individual species. The previous indicator assessment relied on a suite of demersal fish species, which were caught frequently in scientific groundfish surveys, but did not provide assessment results for rare species caught in low frequencies. This study introduces a new assessment approach, the Binomial Occurrence Assessment (BOA), for the FC-1 indicator now renamed the “Recovery of sensitive fish species”, by applying the binomial distribution to relative occurrence data from scientific fisheries surveys. BOA uses occurrences in a reference period to determine boundaries for the expected occurrences in the recent (six year) assessment period of each survey. Significant changes in occurrence between the reference and assessment period, i.e. declines or recoveries, can then be detected when the observed occurrences in the assessment period fall outside of these boundaries. Methods to integrate the assessment results across multiple surveys are explored and compared since data on occurrences for fish species are available from more than one fisheries survey in each marine region considered by OSPAR. A case study on the sensitive demersal fish species in the North Sea exemplifies the applicability of BOA. Furthermore, assessments by BOA are compared to data from analytical stock assessments for those data-rich sensitive species that can support both approaches. Despite some shortcomings of BOA, such as the inability to detect declines of very rare species and the potential for occurrence metrics to differ from abundance metrics, the BOA allows an assessment of the status of a wide suite of fish species throughout the entire OSPAR region. The low data requirements of BOA allow its generic application to any other monitoring program that has captured occurrences of single species or species suites in the past and present.

Understanding how individuals within populations are connected genetically and through shared space-use is critical to understanding the demographic patterns of at-risk populations. In recent years, non-invasive genetic sampling methods have allowed us to begin addressing these questions. Using a network analysis framework, we examined the spatial co-occurrence and genetic relatedness of boreal and central mountain caribou (Rangifer tarandus) in populations varying in sizes and trend from across western Canada. Using 15 microsatellites loci and a sex-specific marker, we developed pedigree networks for each population, including first to third order relationships. We constructed networks of individual spatial co-occurrence, and using multilayer network analysis, we determined the degree to which caribou that co-occurred spatially were related. Caribou populations varied in the extent and classes of familial relationships which co-occurred in space. In most populations, spatial co-occurrences were greater than expected only for parent-offspring relationships. A sex-specific analysis of the longest sampled population revealed that this was driven by a significant overlap between mothers and their offspring. Whereas in populations where very few parent-offspring relationship were detected, no significant overlap was found between any relationship categories. The lack of overlap in these populations may be an indication of poor calf survival. On the other hand, the higher degree of overlap with more distant relations (i.e., grandparents) seen in some populations may indicate a population that lacks mobility. Our research presents a new approach to explore both spatial and genetic overlap at the individual level in support of the conservation of threatened populations.

India is one of the few countries in the world that is home to a significant population of elephants. These majestic animals are an integral part of the country's culture and ecosystem. However, the population of elephants in India has been declining rapidly due to habitat loss, human-elephant conflict, poaching and other anthropogenic factors. This research paper aims to study the current population status and major hazards faced by elephants in India. The study is based on survey methods. The research findings suggest that the population of elephants in India has declined by 10% in the last decade. The major hazards faced by elephants in India include habitat loss, fragmentation, and degradation, human-elephant conflict, poaching, and electrocution. The research concludes with recommendations for the conservation of elephants in India, including habitat restoration, wildlife corridors, and mitigation measures for human-elephant conflict. [ABSTRACT FROM AUTHOR]

Polygonatum cirrhifolium (Wall.) Royle and Polygonatum verticillatum (L.) All. are important medicinal herbs of the 'Ashtavarga group' of medicinal plants and belongs to the family Asparagaceae. The populations of these species are declining in the natural habitat due to various anthropogenic factors; hence, it is important to know existing status of the species for devising conservation and management plan. Keeping that in view, study was conducted in different geographical locations of Himachal Pradesh during June-September 2019. Nine sites falling in four districts for P. cirrhifolium and 23 sites falling in five districts for P. verticillatum were selected to assess their population status by quadrat method using random sampling and following vertical belt transects approach. The population of the P. cirrhifolium was recorded maximum at Kulang site (Dm-2 = 7.27 ± 10.91, F = 23.33%), and lowest at Shakoli (Dm-2 = 0.43 ± 0.82, F = 13.33%). The value of abundance ranged from 2.89 (Batseri) to 14.25 (Nichar). IVI was found maximum at Kulang (61.72) and the lowest at Shakoli (9.16) site. Whereas population of P. verticillatum was recorded maximum at Hatu (Dm-2 = 8.33 ± 3.43, F = 60%), and lowest at Paneta Khud (Dm-2 = 0.73 ± 1.24, F = 20.0%). The value of abundance ranged from 3.62 (Kothi) to 13.89 (Hatu). Frequency was found maximum at Baghi (66.67%) and lowest at Paneta Khud (20.0%). The Shannon diversity index and IVI was found maximum at Jamathu (0.36 and 91.02) and lowest at Paneta Khad (0.18 and 19.81). Both species were distributed in small populations with low density and frequency and were found geographically isolated. [ABSTRACT FROM AUTHOR]

Our recent study compared monitoring data collected using surrogate metrics during 2014–2018 inclusive with baseline data from 2007 to evaluate the trajectory of the population status of the threatened heath skink Liopholis multiscutata in Victoria. The heath skink is a secretive burrowing species that is a habitat specialist and exists in north‐western Victoria as a few small and highly disjunct populations on large dunes in semi‐arid heathland or mallee. We re‐assessed the trajectories of the Victorian populations with additional monitoring data collected in 2021 and found continuing decline across all four Victorian heath skink populations. Urgent management intervention is required to arrest this decline, likely due to predation, reduced availability of habitat and life history and demographic traits that make this species susceptible to decline. [ABSTRACT FROM AUTHOR]

Understanding the impact of human disturbance on the breeding habitat selection of endangered species is critical to improving their conservation. Blue-crowned Laughingthrush Pterorhinus courtoisi (Ménégaux, 1923) syn. Garrulax courtoisi (Passeriformes: Leiotrichidae) is an endangered species in China. To explore the nesting habitat selection of the Blue-crowned Laughingthrush and its response to human disturbance during the breeding period, we conducted a field survey at its nesting sites in Wuyuan County and Dexing City, Jiangxi Province, from March to July 2021 and in June 2022. At the home range scale (200 m) the results of a principal component analysis (PCA) showed that this species had a clear preference for infrastructure construction, grassland, farmland and bare land. At the microhabitat scale (12.26 m), we compared the ecological parameters of a nest plot and control plot using a Kruskal–Wallis H test and found that there were significant differences in the vegetation coverage, crown breadth, shrub coverage, herb maximum height, herb average height and herb species number of the nesting area between the two groups. Ensemble species distribution models showed that the suitable habitat of the Blue-crowned Laughingthrush covered an area of 108.67 km2. Distance to waterways, deciduous broadleaved forests and roads were the main factors impacting the habitat distribution of the Blue-crowned Laughingthrush. Our study suggests that (1) it is highly important to improve the protection of breeding sites and suitable living areas close to the settlements and preserve a certain nesting habitat selection space for the Blue-crowned Laughingthrush during the breeding period; and (2) it is necessary to continue to monitor the potential suitable breeding habitat. This study provides a scientific basis for the protection of the Blue-crowned Laughingthrush by local forestry bureaus and conservation departments in the future. [ABSTRACT FROM AUTHOR]

Australia's Red Goshawk (Erythrotriorchis radiatus) is a taxonomically distinct raptor endemic to the tropics and sub-tropics of eastern and northern Australia, and the Australian mainland's rarest bird of prey. Classified as Vulnerable when legislation was first enacted in 1992, the species' status and distribution remain unclear, and it is possibly declining based on limited surveys. However, no comprehensive analysis of its range-wide population trends has ever been undertaken, creating a knowledge gap which potentially delays urgent conservation management. Here, we bridge that knowledge gap. We compile a comprehensive dataset of 1,679 occurrence records spanning the species' historical range, develop a novel method that overcomes reporting biases centred around nest locations, then identify population trends between 1978 and 2020 at national, state, and regional scales. Our results suggest that the species has declined significantly across eastern Australia and is likely locally extinct in many regions. We estimate the Red Goshawk has disappeared from 34% of its breeding range over the last four decades, and probably persists at extremely low density, if at all, over an additional 29.7% of its breeding range. These results demonstrate the species' declining population trajectory at multiple scales for the first time and provide further evidence for its up listing under Australian federal legislation to Endangered, using IUCN Red List criterion C2a(ii): small population size and decline. We recommend population surveys and monitoring coupled with targeted research to better understand population trajectories and determine which threats are driving this unique species' decline. [ABSTRACT FROM AUTHOR]

Arctic Russia is home to more than 90% of all Long-tailed Ducks in the Clangula hyemalis species from the Western Siberia/Northern Europe population. The breeding population in European Russia was estimated to be about 5 million birds in the 1960s, while today, estimates have declined to 1 million birds. Up until now, the main reasons for the overall population decline of the Long-tailed Duck were related to wintering conditions in the Baltic Sea. Our data indicate that the loss or deterioration of key breeding habitats in the Arctic regions of Russia is one important factor influencing the rapid population decline. Many key breeding habitats of the Long-tailed Duck were completely lost in the Bolshezemelskaya tundra, as this area was transformed into major oil and gas extraction sites. The transformation of these sites increased the disturbance and oil pollution of adjacent habitats, leading to the direct loss of certain key nesting sites and a marked and rapid decline of the breeding population of the Long-tailed Duck in the Bolshezemelskaya tundra. Oil-spills during transportation by sea may also be an important factor of decline in the Long-tailed Duck population. Meanwhile, in the Malozemelskaya tundra, which did not experience oil and gas development, the breeding population over the last decades remained stable. Urgent establishment of new protections in key breeding areas in Arctic Russia, sustainable population management, and new research programs are necessary for the conservation and enhancement of this globally threatened species. [ABSTRACT FROM AUTHOR]

The bulk of the chinstrap penguin (Pygoscelis antarcticus) global population inhabits the Antarctic Peninsula and Scotia Sea, which is a region undergoing rapid environmental changes. Consequently, regional level decreases for this species are widespread. This study aimed to evaluate the level of breeding colony changes in the Antarctic Peninsula and South Orkney Islands, which, roughly, hold 60% of the global chinstrap penguin population. The results indicated that within a period of 40 to 50 years, 62% of colonies underwent decreases, and the majority of colonies experienced decreases over 50%, which is represented by numbers in the range of 2000 to 40,000 pairs. Within three generations' time, the whole population for the area had experienced decreases of around 30%. These levels of decrease add to the fact that the suspected causes are not likely reversible in the short- to mid-term, calling for increased concern about the conservation of this species. [ABSTRACT FROM AUTHOR]

The state of populations of European grayling Thymallus thymallus (Linnaeus, 1758) has been assessed and compared in two Ural tributaries of the Pechora River. The grayling inhabiting the Shchugor River (the territory of Yugyd Va National Park) has been satisfactorily preserved with minimal shifts in population characteristics. In the Bolshaya Synya River, protected only at the river source, the grayling population decreased mostly by the fish of the maximum age (up to 7+), the share of repeatedly spawning individuals has decreased as well (4.0–4.8%), and the overall mortality rate has increased. Deterioration of the grayling population in the Bolshaya Synya River was due to intensive illegal fishing. Under limited initial data, using a set of traditional indicators appeared a more universal assessment approach, while the length-based indicators (LBIs) method has only limited application. [ABSTRACT FROM AUTHOR]

Theropithecus gelada is endemic to Ethiopia, mainly in the northern part of the Ethiopian plateau. Despite the relatively long-term research efforts on the population and behavioural ecology of geladas, and its conflict with humans in protected areas, these data are lacking in unprotected areas. Accordingly, this study was conducted to determine population status and to assess human-gelada conflicts around Debre Berhan town. The total count method was adopted during November 2013 - April 2014 to assess population status and data on human-gelada conflicts were collected based on a direct questionnaire survey. A total of 438 geladas were counted during the study period. The number of females was significantly higher than the number of males (÷2 =45.48, df =1, P < 0.05) with a ratio of 1:2.3 males to females. The mean group size of gelada was 43. Fifty seven percent of respondents had negative attitude towards geladas, whereas 30.0% had a negative attitude and 12.3% had neutral attitudes. The average annual crop loss by gelada was 2 quintal per household. The trend of crop damage by geladas is increasing significantly in the study site during the last ten years (÷2 = 44.47, df = 2, P < 0.05). The study helps future conservation of species in unprotected areas in the vicinity of agricultural lands. [ABSTRACT FROM AUTHOR]

Proboscis monkeys, an iconic Bornean endemic species, are facing threats from habitat loss, degradation, and fragmentation due to human activities. Past surveys have covered only a limited number of proboscis monkey populations across their range, leaving the status of many populations largely unknown. We surveyed the previously unexplored Kota Belud region in northwestern Sabah, Malaysian Borneo, to determine the population and distribution of proboscis monkeys. Our assessment of the threats to their survival focused specifically on land-use and land-cover patterns, with the primary goal of evaluating the population status of proboscis monkeys in this region through an analysis of habitat change. Between January and September 2022, we conducted boat-based surveys in wetland forests—potential habitats of the proboscis monkeys. Of the six sites we surveyed, we directly observed proboscis monkeys at just one, although local residents reported their presence at other sites. Our observations identified 25 individuals in at least three one-male-multifemale groups and one all-male group, all along the Tempasuk River near the coastline. Overall, our study highlights the concerning state of the proboscis monkey population in Kota Belud, which is small, highly fragmented, and likely reaching its limits of adaptability to habitat changes due to human activities. While acknowledging the need for further studies, urgent conservation strategies are needed. For the long-term survival of the proboscis monkeys in Kota Belud, we recommend prioritizing the identification and protection of remaining habitats, rehabilitation, reconnection of isolated areas, and proactive measures to prevent further habitat fragmentation. [ABSTRACT FROM AUTHOR]

Summary: The little-known Bristled Grassbird Chaetornis striata is thought to be declining due to the loss of grassland habitats throughout its range, and is currently classified as globally 'Vulnerable'. In order to investigate the current status and possible causes of the presumed decline, we assessed population density of Bristled Grassbird in Padma and Jamuna river systems of Bangladesh. The study was conducted during the breeding seasons of the Bristled Grassbird in April and May in 2016–2019, using distance sampling and habitat suitability modelling. We also examined habitat preferences and responses to environmental changes based on vegetation structure and habitat modifications at point count locations. We detected a total of 39 birds with a mean group size of 1.44 individuals. We estimated 4.52 (95% CI: 2.65–7.73) individuals per km2 with an encounter rate of 1.48 detections per point count station and 341.15 birds within the study area. Our habitat suitability model projected a total of 167.41 km2 of suitable habitat and a total of 756.7 birds in floodplain grasslands of Padma and Jamuna river systems. The Bristled Grassbird was positively associated with grass height and grass density with 92.31% of 39 detections at Saccharum spontaneum dominated grasslands. We did not find a significant effect on Bristled Grassbird detections with increasing human activities, although the detection rate decreased linearly with increasing agricultural intervention and grass harvesting. These findings indicate that the Bristled Grassbird is more widely distributed throughout Bangladesh, and may be less vulnerable to grassland modifications, than previously thought. [ABSTRACT FROM AUTHOR]

Based on the analysis of the genetic polymorphisms (RGAP- and CDDP-PCR) among populations and comparison of these results with ecological characteristics (density, area, spatial and vitality structure, age, ability of renewal and self-maintenance), the status of five natural (Lemska, Gutyn Tomnatyk, Sheshul-Pavlyk, Krachuneska, Troyaska-Tataruka) and one man-made (Pozhyzhevska) populations of Gentiana lutea from the Ukrainian Carpathians was assessed. The results of the complex ecological and genetic analysis have revealed that three populations are unstable (Krachuneska, Troyaska-Tataruka, Gutyn Tomnatyk), two are relatively stable (Lemska, Pozhyzhevska) and only one is stable (Sheshul-Pavlyk). The research results can be used for stabilizing the number of violations and restoring the endangered natural populations. Based on these data, the recommendations for the conservation and protection of G. lutea populations have been developed.

A study on population status and distribution of Assamese macaque (Macaca assamensis) across altitudinal gradients in Dampa Tiger Reserve (DTR), Mizoram, India was conducted. Six species of diurnal primates inhabits in DTR and a study on Assamese macaque is reported here. Line transact method was adopted for population sampling. Total distance covered was 293.5 km. Data on group locations, demography and site covariates including trail length, duration of walk, forest type were recorded. Nine groups of Assamese macaque comprising of 123 individuals were recorded mostly at an altitude between 250 m to 856 m. The smallest group was consisted of 7 individuals, and the largest was of 21 individuals. An average group size calculated was 13.6 (±4.32) individuals. The population comprised of 36.59% male, 53.66% female, and 9.76% immature. All the groups were comprised of multi-males and multi-females. The population encounter rate was 0.42 individual/km and the group encounter rate was 0.03group/km. Total male to female ratio was 1:1.46, adult adult male to female ratio was 1:1.53. All female to immature ratio was 1:0.18 and an adult female to immature ratio was 1:0.26. Maximum sighting were at the distance between 30-50 m. Area of occupancy of groups was about 26 km2 and ecological density was 4.7/km2. Among primates in DTR, wild population of Assamese macaques were found to occupy altitudinal range between 250 to 856 m. 67% individuals were distributed at the altitude between 400 to 600 m. Presence of other primate species in DTR restricted the occurrence of this species. [ABSTRACT FROM AUTHOR]

The Indian wolf, Canis lupus pallipes is an endangered carnivore of India listed in Schedule-1 of the Indian Wildlife (Protection) Act, 1972. There is not much information available on the species and with this perspective, the present study was initiated in the Great Indian Bustard Sanctuary in Maharashtra. Direct and indirect evidences were used to assess its population status and distribution, habitat use, feeding ecology, denning behaviour and wolf-human conflict emanating due to livestock depredation. Intensive ecological and behavioural studies were conducted at Nannaj on one pack between 1991 and 1994. The wolf survives all over the Sanctuary, which is densely populated by humans as elsewhere in its distribution range in India where wolf-human conflicts are common arising either due to livestock depredation or child-lifting. Usually, large packs were present in blackbuck Antilope cervicapra areas whereas smaller packs inhabited areas not supporting healthy populations of blackbuck. In blackbuck poor areas, the wolf survived mainly on livestock. The Sanctuary supports 40-58 wolves. The wolves had a seasonal pattern of habitat use related to movement of prey and livestock. Wolves selected those areas as rendezvous sites which had higher prey density, vegetation cover, minimum human disturbance and were located close to water source. On an average wolves consumed 3.68 (S.E.=0.17) kg/wolf/kill and kill periodicity was 3.65 days (S.E.=0.58). Wolves preyed largely on blackbuck during the non-breeding period and livestock during denning period. Predation was higher on male blackbuck than females despite female biased sex ratio. The average litter size of three packs was recorded to be 5 (range 4-6). The dominant male and female wolves guarded the dens more often than the helpers. They used multiple dens for raising pups that were excavated and/or renewed during denning period. Important conservation problems of wolf have also been discussed in the paper. [ABSTRACT FROM AUTHOR]

Methods used to monitor variation in population sizes in both Atlantic salmon and anadromous brown trout (sea trout) have been widely used in Norway the last 20 years. However, a national management regime, based on population data, has only been established for one of the two species, the Atlantic salmon. One prerequisite for using this "one species" model is that there is negligible interspecific competition between salmon and trout in the rivers. This may, however, be an oversimplification of the real situation. The pre-fishery abundance (PFA), monitored with combination of underwater video systems, snorkelling counts, and catch statistics will, in most rivers, include both salmon and Sea Trout. In the present study, we estimated a total PFA for rivers, or groups of rivers, in eight regions in Norway in 2019. The total size of each river system was measured by abiotic factors such as river area, river length, annual mean water flow, and size of precipitation field; additionally, one biotic factor, smolt age, was used to standardise PFA data across regions. A comparison shows that the standardised total PFA of salmon and trout varies across regions where the highest estimated PFA was four times higher than the lowest. Compared to the traditional one-species approach, the merged PFA data show a different population status in the eight regions. The difference in the two approaches was mainly linked to the variation in size in anadromous brown trout populations. Merging data from salmon and trout populations in defined regions may be a better input in a management model than the current model used by the Norwegian Scientific Committee for Salmon Management (VRL). [ABSTRACT FROM AUTHOR]

With the ongoing global biodiversity crisis in the Anthropocene, it is critical to understand how to save endangered species to "bend the curve" of biodiversity decline. The Hainan gibbon (Nomascus hainanus) is a Critically Endangered species that is endemic to Hainan Island. We performed two synchronized total count surveys in Hainan Tropic Rain Forest National Park in November and December of 2020 and 2021 by locating gibbon groups from their morning calls and conducting detailed counts in all potential habitat fragments. We compared our findings with existing data to model the population trend, and analyzed the potential and realized reproductive potentials. We found 5 groups with a total of 33 gibbons in 2020 and 35 in 2021, including 4 and 6 solitary individuals respectively. This is an increase of 169% since 2003, when there were 13 individuals with 2 groups and 2 solitary individuals. Logistic and linear curves fitted the 2003-2021 population census data equally well. Although the population is growing, it has not realized its full reproductive potential (when all adult females give births at 24-month intervals), suggesting that external factors like available habitat, as well as nutritional, physiological, and behavioral factors may be limiting the population. The gibbon's recovery demonstrates that establishing a nature reserve with regular patrols, banning logging, curbing poaching, and environmental education have been effective. Because the Hainan gibbon population is still extremely small, carefully planned conservation actions, including an ambitious forest restoration program, will be needed to ensure the species' continued survival. [ABSTRACT FROM AUTHOR]

Common hippopotamuses (Hippopotamus amphibious) are among the top five herbivorous animals in Africa. Despite being listed as a vulnerable species by the International Union for Conservation of Nature, they are a common mammal in Ethiopia's protected areas, lakes, rivers, and marshes. However, there is insufficient data to evaluate status of the population and habitat compatibility across the most of the country. The aim of this research was to ascertain the population size of hippos and the suitability of its habitat in the Dhidhessa Wildlife Sanctuary (DWS) in southwest Ethiopia. The study was conducted between 2021 and 2022. To estimate the population size, the total count procedures were employed. The adaptability of each habitat for hippos was determined using the multi-ring buffer analysis in Arc GIS 10.2. A total of 231 and 133 hippos were observed during both the dry and wet seasons, respectively. Of the surveyed individuals, 62.08 % were adults, 20.88 % were under-adults, and 17 % were young. More hippos (45.1 %) were observed in the savanna grassland during the rainy season. Subsequently, the hippos (50.6 %) relocated to the riverine forest in the dry season. Thus, the habitats in DWS and their environs were determined to range from most suitable to unsuitable for hippos. The results showed that 58.31 % of the regions were unsuitable, 18.49 % were moderately suitable, and 23.18 % were highly suitable for hippos grazing. 7.95 % of the research area slope was suitable, 26.32 % moderate and 65.72 % not suitable and 19.8 % was considered most suitable for human interference, 46.3 % was severely disturbed, and 33.9 % was moderately affected. Based on the current investigation, it has been determined that human interference in hippos' habitats is significant. In order to protect the hippos' habitats from excessive human activities and their impacts, a buffer should be created around the DWS area., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The article presents the results of the Steppe Eagle (Aquila nipalensis) study in the Republic of Kalmykia. 135 breeding territories of eagles were examined and 155 birds were observed during summer registrations and counts. The average distribution density of the occupied breeding territories in 2021 in the main part of the area was 2.15 (1.54–2.99)/100 km², in the zone of the large number of food resources – 5.72 (4.45–7.35)/100 km². The percentage of occupied breeding territories was 71%, and 43% of the occupied territories were successful. The number of nestlings in broods ranged from 1 to 3, averaging 1.81±0.69 per successful nest (n=43) and 0.73±0.95 per occupied nest (n=105). The percentage of nests with dead clutches and nestlings was high at all registration plots. The main diet of eagles during the breeding period included the Little Ground Squirrel (Spermophilus pygmaeus) (44%) and several additional prey items. A preliminary assessment of habitat suitability for the Steppe Eagle in terms of food conditions was carried out using GIS methods. Based on the registration data and clarification of the breeding range borders (47086.7 km²), the number of the Steppe Eagle in Kalmykia was re-estimated at 789 (587–1059) pairs. The signs indicating a negative trend in the population intensified: the percentage of immature birds in breeding pairs was 27%, the percentage of abandoned breeding territories was 19%. There is a consolidation of breeding groups in the population nucleus with a simultaneous decrease in breeding density at the periphery. Among the negative anthropogenic factors in 2021 there were the following: mass mortality on power lines, destruction of the food potential by the locals, disturbance during breeding, probable taking away of nestlings from nests.

With the advent of the golden jackal in the Lower Dnister, certain changes have taken place in natural complexes, which are primarily related to the impact of the new species on the local fauna. Under such conditions, the number of jackals in certain areas, the spatial structure and location of separate packs are important information for the development of measures aimed at maintaining an optimal abundance of this species. Given the active impact of wildlife on natural systems, there are a number of both biological and purely social problems that need to be addressed. The effectiveness of solving such problems directly depends on the level of study of various aspects of biology and ecology of jackals. In addition, knowledge of the current state of the Dniester jackal population allows timely and effective response to new environmental challenges, which are associated with an increase in the abundance of new species and in its impact on the native mammal fauna. The results of the research indicate a certain competition of the jackal with other species of predatory mammals, in particular the fox and the raccoon dog. Thus, within the territories where the study was carried out, with the appearance of the jackal at the lower course of the Dnister, the red fox was not observed at all and the number of raccoon dogs decreased significantly. Habitats of separate jackal groups within the Lower Dnister National Nature Park have been identified and their total abundance has been established. The dynamics of settlement by the species of the Lower Dnister area is analysed, the conservatism of the species in relation to the residential areas is indicated. It has been established that in some parts of the park, in particular on the northern bank of the Dnister Estuary, the density of animals is about 12 individuals per 1000 hectares, which significantly exceeds the permissible sanitary and epidemiological standards. At the same time, in some parts of the floodplains of the Lower Dnister, density exceeds 0.5 individuals per 1000 ha, which indicates a complex spatial distribution of separate packs and groups of jackals. Mapping of the number of jackals in the park showed that groups far from the estuary are smaller in number (6–14 individuals), whereas groups near the estuary are more abundant (13–20 individuals).

Arctic Russia is home to more than 90% of all Long-tailed Ducks in the Clangula hyemalis species from the Western Siberia/Northern Europe population. The breeding population in European Russia was estimated to be about 5 million birds in the 1960s, while today, estimates have declined to 1 million birds. Up until now, the main reasons for the overall population decline of the Long-tailed Duck were related to wintering conditions in the Baltic Sea. Our data indicate that the loss or deterioration of key breeding habitats in the Arctic regions of Russia is one important factor influencing the rapid population decline. Many key breeding habitats of the Long-tailed Duck were completely lost in the Bolshezemelskaya tundra, as this area was transformed into major oil and gas extraction sites. The transformation of these sites increased the disturbance and oil pollution of adjacent habitats, leading to the direct loss of certain key nesting sites and a marked and rapid decline of the breeding population of the Long-tailed Duck in the Bolshezemelskaya tundra. Oil-spills during transportation by sea may also be an important factor of decline in the Long-tailed Duck population. Meanwhile, in the Malozemelskaya tundra, which did not experience oil and gas development, the breeding population over the last decades remained stable. Urgent establishment of new protections in key breeding areas in Arctic Russia, sustainable population management, and new research programs are necessary for the conservation and enhancement of this globally threatened species.

Sea otters (Enhydra lutris kenyoni) historically occurred in Washington State, USA, until their local extinction in the early 1900s as a result of the maritime fur trade. Following their extirpation, 59 sea otters were translocated from Amchitka Island, Alaska, USA, to the coast of Washington, with 29 released at Point Grenville in 1969 and 30 released at La Push in 1970. The Washington Department of Fish and Wildlife has outlined 2 main objectives for sea otter recovery: a target population level and a target geographic distribution. Recovery criteria are based on estimates of population abundance, equilibrium abundance (K), and geographic distribution; therefore, estimates of these parameters have important management implications. We compiled available survey data for sea otters in Washington State since their translocation (1977–2019) and fit a Bayesian state‐space model to estimate past and current abundance, and equilibrium abundance at multiple spatial scales. We then used forward projections of population dynamics to explore potential scenarios of range recolonization and as the basis of a sensitivity analysis to evaluate the relative influence of movement behavior, frontal wave speed, intrinsic growth, and equilibrium density on future population recovery potential. Our model improves upon previous analyses of sea otter population dynamics in Washington by partitioning and quantifying sources of estimation error to estimate population dynamics, by providing robust estimates of K, and by simulating long‐term population growth and range expansion under a range of realistic parameter values. Our model resulted in predictions of population abundance that closely matched observed counts. At the range‐wide scale, the population size in our model increased from an average of 21 independent sea otters (95% CI = 13–29) in 1977 to 2,336 independent sea otters (95% CI = 1,467–3,359) in 2019. The average estimated annual growth rate was 12.42% and varied at a sub‐regional scale from 6.42–14.92%. The overall estimated mean K density of sea otters in Washington was 1.71 ± 0.90 (SD) independent sea otters/km2 of habitat (1.96 ± 1.04 sea otters/km2, including pups), and estimated densities within the current range correspond on average to 87% of mean sub‐regional equilibrium values (range = 66–111%). The projected value of K for all of Washington was 5,287 independent sea otters (95% CI = 2,488–8,086) and 6,080 sea otters including pups (95% CI = 2,861–9,300), assuming a similar range of equilibrium densities in currently un‐occupied habitats. Sensitivity analysis of simulations of sea otter population growth and range expansion suggested that mean K density estimates in currently occupied sub‐regions had the largest impact on predicted future population growth (r2 = 0.52), followed by the rate of southward range expansion (r2 = 0.26) and the mean K density estimate of currently unoccupied sub‐regions to the south of the current range (r2 = 0.04). Our estimates of abundance and sensitivity analysis of simulations of future population abundance and geographic range help determine population status in relation to population recovery targets and identify the most influential parameters affecting future population growth and range expansion for sea otters in Washington State. [ABSTRACT FROM AUTHOR]

The hog deer Axis porcinus formerly occurred in south-west China but has not been recorded there since 1965. To investigate the current status of the species in China, we conducted interviews, and transect and camera-trap surveys during October 2018–June 2020 to search for signs of hog deer across its historical range in the country. We interviewed 50 local inhabitants and surveyed 14 line transects in four counties of Lincang City, Yunnan Province. The camera traps were deployed in Nangunhe Nature Reserve (39.4 km of transects, 82 camera stations, 15,120 camera days) and Daxueshan Nature Reserve (41.1 km of transects, 68 camera stations, 13,554 camera days). We found no hog deer tracks and no hog deer were trapped by cameras. The floodplain grasslands preferred by hog deer along Nanting River have been transformed into agriculture plantations and human settlements. Our findings suggest that hog deer may have been extirpated from China, most likely as a result of habitat loss and overhunting. The conservation priorities for this species in China are the establishment of a protected area in the Nanting River watershed, restoration of habitat and reintroduction of individuals from range countries. [ABSTRACT FROM AUTHOR]

Landbird populations on Tinian Island have been periodically surveyed since 1982 to evaluate the status of non-native and native landbirds. We report the results of surveys in 2013 and the observed changes during 31 years in species population trends based on surveys since 1982. A total of 11 native and 3 non-native species were detected during the 2013 survey. Population sizes were estimated using point-transect distance sampling methods, and population trends were assessed using repeated measures analysis of variance for nine forest bird species. In all years, the Rufous Fantail (Rhipidura rufifrons) and Bridled White-eye (Zosterops conspicillatus) were the most abundant species, whereas the White-throated Ground Dove (Pampusana xanthonura) was the least abundant species in 1982, 1996, and 2008, and the Mariana Kingfisher (Todiramphus albicilla) was the least abundant in 2013. The less common species numbered in the low thousands included the Mariana Fruit Dove (Ptilinopus roseicapilla), White-throated Ground Dove, introduced Philippine Collared Dove (Streptopelia dusumieri), Mariana Kingfisher (Todiramphus albicilla), and Micronesian Myzomela (Myzomela rubratra). The Micronesian Starling (Aplonis opaca) and Tinian Monarch (Monarcha takatsukasae) were estimated to number in the tens of thousands. The most abundant species were the Rufous Fantail, numbering more than 100,000, and the Bridled White-eye, numbering more than 400,000. The overall trends in abundance between 1982 and 2013 showed an increase in the Mariana Kingfisher, Micronesian Starling, Rufous Fantail, White-throated Ground Dove, and Philippine Collared Dove, while populations were stable for the Bridled White-eye and Tinian Monarch. Declines were seen for the Mariana Fruit Dove and Micronesian Myzomela. These trends matched previous analyses with the exception that Tinian Monarch abundance showed an increase in the 2013 survey. [ABSTRACT FROM AUTHOR]

Globally, competition and disease from introduced Red-eared Slider (Trachemys scripta elegans) is a threat to co-existing native turtles. Red-eared Slider has been introduced throughout south coastal British Columbia (BC), mainly as pet turtle releases. Urban centres receive the most individuals, particularly in the Lower Mainland area outlying Vancouver, on southern Vancouver Island, and on the Sunshine Coast. The range of Red-eared Sliders in BC overlaps that of the Threatened Pacific Coast population of Western Painted Turtle (Chrysemys picta bellii). Herein we report on a survey for both species, noting presence, assessed population sizes, and nesting activity. Across 19 sites in the south coast occupied by both turtle species, we found the median abundance of Red-eared Sliders to be 2.5 times larger than that of Western Painted Turtles (Mann--Whitney U = 104, n1 = n2 = 19, Z-Score = -2.2188, P = 0.02642, two-tailed). There had been no evidence of Red-eared Sliders successfully hatching in the wild in BC until our study. We observed complete development, with 19 neonates from three different nesting sites between 2015 and 2017. Thus, Red-eared Slider is indeed established and able to breed in BC and thus competition and disease introduction from the species likely contributes to the decline of the Pacific Coast population of Western Painted Turtle, particularly at sites with low painted turtle numbers. The scale and mechanisms of impact requires further investigation. [ABSTRACT FROM AUTHOR]

Despite widespread concern about biodiversity declines, few empirical studies exist on long-term population trends of mammal carnivores. In the context of global change, it is essential to understand the population trends and resource use of mammal carnivores. Mammal carnivores fulfil an important ecosystem function in terrestrial ecosystems as their top-down role directly and indirectly influences prey populations which affects the entire food web. The objective of this study was to evaluate whether and how the population trends of two sympatric mustelid species, stone marten and polecat, have changed between 1998 and 2013 in Flanders, Belgium. In addition, we explored temporal changes in their dietary habits. From 1998–2013, in collaboration with a citizen science network, we collected road-killed animals over the entire area of Flanders (13,682 km²). Based on the number of collected road-killed animals we detected a decrease in the polecat population during 1998–2013 whereas the stone marten population has increased. By subsequent identification of the stomach contents of the specimens, we detected fluctuations throughout the year of the consumption of certain food types. In addition, the consumption of certain food items decreased (stone marten: fruits, grains and nuts and lagomorphs; polecat: birds, rodents and other mammals) or increased (stone marten: edible waste and polecat: amphibians) throughout this period of opposite population trends. An increase of the degree of specialization of the diet throughout the sampling period was also detected for both mustelid species. In summary, our study concludes contrasting population trends coupled with clear changes in feeding habits of two sympatric carnivore species. Understanding these long-term relationships between species population trends and their dietary ecology is vital for biodiversity conservation and nature management.