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The Bathurst caribou (Rangifer tarandus groenlandicus (Borowski, 1780)) herd declined from ∼349 000 animals in 1996 to ∼8200 in 2018. Climate-driven changes to tundra and boreal vegetation is one hypothesis for the decline. We modelled and mapped annual productivity and phenology across the herd’s range using enhanced vegetation index (EVI) data derived from a Moderate Resolution Imaging Spectroradiometer (MODIS) time series spanning 2000–2017. Maximum annual EVI, growing season length, and time-integrated EVI increased significantly on 16%, 18%, and 49% of the core annual range, respectively. Trends toward longer growing seasons were driven entirely by earlier spring green-up and, along with time-integrated EVI, were most prevalent in tundra regions. Trends in forested regions were overwhelmingly related to the influence of forest fires, which burned more than half of the range below the forest–tundra ecotone since 1965. These trends suggest that climate-driven changes in production and phenology have occurred in the tundra and forest–tundra portions of the range and could have contributed to the recent herd decline. However, the trends may also be a result of herd decline itself, given the loss of this large herbivore from the landscape. Elucidating cause and effect will require comprehensive analysis of interactions between climatic variables, herd dynamics, and vegetation change, complemented by targeted field investigations.

Purple Martins (Progne subis) are Neotropical migratory birds that breed across North America and spend their nonbreeding season in South America, primarily Brazil. They have been in a long-term population decline over the last five decades. There are several suggested causes for the decline, but to begin understanding the conservation needs of this species, it is necessary first to fill existing knowledge gaps about migration timing, distribution, and habitat use in Brazil. The presence of this species across most of Brazil makes it difficult to keep track of seasonal or long-term changes in its distribution without careful, widespread data collection. Citizen science offers an emerging opportunity to address knowledge gaps of roost distribution and phenology. Here, we compiled Purple Martin records from citizen science platforms, scientific collections, and bibliography to produce an overview of the distribution and phenology of the species in Brazil. It is present in most Brazilian states, but records are concentrated in the Amazon region. Previously known large roosts in southeast Brazil, especially in the state of Sao Paulo, have decreased in number of individuals over the last decade. Most records are from September to April, although phenology varies with latitude. In the equatorial region (5°N–5°S), which is crossed by all populations that come to Brazil, the number of reports shows strong temporal variation, probably related to the timing of migration in different populations.

The unprecedented growth of human-dominated landscapes has led to population decline and the extinction of many animal species. A major paradigm shift that perceived wildlife as problem animals into threatened species that need protection triggered human-wildlife conflict studies. Although human-wildlife conflict incidences can be found globally, they have unique characteristics in each region of the world. However, little is known about the characteristics of human-wildlife conflicts in Southeast Asia, particularly Indonesia. There is a need for a comprehensive insight into human-wildlife conflict studies in Indonesia to understand past advancements and propose future priorities. This study examined the literature that provides the overall view of the human-wildlife conflict patterns in the country. The results showed that there was a comparatively small number of studies because this field was a relatively new subject in Indonesia. Furthermore, there were big gaps regarding animal species and the geographic distribution of study sites. A total of 35 species belonging to eight taxonomic groups experienced conflicts with humans. However, the studies heavily focused on three groups of animals and certain areas of the country. The predominant conflict sites were secondary forest, agroforestry, and farmlands. The conflicts in these areas unveiled the significance of local beliefs and social norms for formulating mitigation strategies.

In Denmark, many rural schools have been closed since 2000. These school closures have often resulted in heated debates between local politicians and the local population. Locals have feared that closing their school would have adverse effects and lead to local population decline. Meanwhile, previous research has found mixed evi-dence on the population effect of rural school closures. The aim of this paper is to contribute to the existing literature by looking at the case of Denmark. The paper analyses the local population effects of the simultaneous closure of eight village schools in 2011 in the same peripheral municipality in Denmark. The case study offers a quasi-experimental setting, and the population effects are estimated through an ordinary and a flexible difference-in-differences (DiD) analysis. Overall, the results show clear evidence of a negative population effect of rural school closures. The ordinary DiD analysis shows a population decline of 7.6 percentage points during the 10-year post-closure period. The flexible DiD analysis points to long-term effects, as the population decline first becomes statistically significant from the sixth year following the closures and onwards. To qualify the results of the econometric tests, we report findings from interviews with local people carried out in 2015 in four of the eight rural communities. Among other things, findings from interviews point to lock-in effects in terms of social capital and housing markets, which helps to understand the dominance of long-term population effects from school closures. In Denmark, many rural schools have been closed since 2000. These school closures have often resulted in heated debates between local politicians and the local population. Locals have feared that closing their school would have adverse effects and lead to local population decline. Meanwhile, previous research has found mixed evidence on the population effect of rural school closures. The aim of this paper is to contribute to the existing literature by looking at the case of Denmark. The paper analyses the local population effects of the simultaneous closure of eight village schools in 2011 in the same peripheral municipality in Denmark. The case study offers a quasi-experimental setting, and the population effects are estimated through an ordinary and a flexible difference-in-differences (DiD) analysis. Overall, the results show clear evidence of a negative population effect of rural school closures. The ordinary DiD analysis shows a population decline of 7.6 percentage points during the 10-year post-closure period. The flexible DiD analysis points to long-term effects, as the population decline first becomes statistically significant from the sixth year following the closures and onwards. To qualify the results of the econometric tests, we report findings from interviews with local people carried out in 2015 in four of the eight rural communities. Among other things, findings from interviews point to lock-in effects in terms of social capital and housing markets, which helps to understand the dominance of long-term population effects from school closures.

According to standardized bird trapping for banding purposes the population trends of Wrynecks (Jynx torquilla Linnaeus, 1758), Lesser Whitethroats (Sylvia curruca Linnaeus, 1758), Tree Pipits (Anthus trivialis Linnaeus, 1758), and Red-backed Shrikes (Lanius collurio Linnaeus, 1758) over 45 years in the Courish Spit, Eastern Baltic, indicate two periods, an initial population growth and a subsequent significant decline. All results, including the already published data on the Barred Warblers, indicate that 5 species of long-distance trans-Saharan migrants experienced a significant decline in numbers since the mid-1970s. Ringing protocol included determination of age and taking biometric measurements, the wing length as a proxy of structural size, and body mass. During the period of population decline, neither wing length, nor body mass of birds changed. None of the indicators of population productivity (clutch size, average brood size, breeding success) did not change, either. Presumably this may mean that the reasons for the population decline of the species are related to factors affecting birds on migration route or in wintering areas, and not on their breeding grounds. It is known that in catastrophic droughts on the African continent, the quality of habitats deteriorates, and competition for food leads to an increase in the mortality rate of wintering birds.

The breeding population of birds are dynamic and are affected by multiple factors including climate and local environmental conditions. However, often to understand such relations requires long-term data modelling. Such long-term population data is either lacking or has data gaps. This study demonstrates the use of Multiple Imputation Chained Equation (MICE) to overcome the problem of missing data population census. This is also the first comprehensive study, modelling the 36-year (1980-2015) long-term breeding population data of a near-threatened bird, Painted Stork, from Keoladeo National Park, India. It tests the effect of local water availability, i.e., water released to the park, and regional rainfall, i.e, climatic condition, on the breeding population using Generalised Additive Model (GAM). Both imputation and observed data series-based GAM models identified the local water availability as the most important factor influencing the breeding population of Painted Stork. More than 80% population decline was observed, despite a slight increase in the rainfall at regional scale, suggesting local hydrological conditions are limiting to the breeding population and not the climate. According to the visual assessment of partial plot of GAM, minimum 200-300 million cubic feet of water is needed each nesting season to ensure sustenance of breeding population. Post-1989, the breeding population was unable to match the long-term mean (~726) except in 1992, 1995, and 1996. The maximum decline was observed between 2000-2009, a decade of frequent droughts. The breeding population was stable until the end of this study, but it was far below the long term mean.

The global population is concentrating unprecedentedly into urban areas, raising concerns on global sustainability and human well-being. There also exists a niche trend of migration from urban to rural areas particularly in countries with post-industrial economies. This paper investigated values of migration expressed by the migrants arrived in Hokuto City, a Japanese rural municipality experiencing pervasive population decline but is also a popular destination for migrants from urban areas. Statistical analyses of 868 responses to a Hokuto City's migrant survey between April 2017 and January 2019 identified their common values of migration, i.e., nature, housing and food. In addition to these common values, households with different demographic characteristics had different priorities: employment for singles in ages between 16 and 29; favorable environment for raising children for married couples in their 30s and 40s; not specific or ‘lifestyle’ for migrants in 50s; and staying with or near family for retirees over 60 years. Knowledge of heterogeneity in migrants and of their values, as described herein, will enable targeted policies and public services concerning migration. Widespread acceptance of teleworking after experiencing the COVID-19 pandemic might offer people of working age, particularly in their 20s and younger, a wider range of options of places to work and live, and thus is likely to influence future urban-rural population flow. A more detailed analysis of the region's natural attributes which are central to the values of migration to rural areas, such as Hokuto City, will be useful to inform regional land use planning that is salient to the values of migrants.

Deforestation and agricultural intensification have resulted in an alarming change in the global land cover over the past 300 years, posing a threat to species conservation. Dhole is a monophyletic, social canid and, being an endangered and highly forest-dependent species, is more prone to the loss of favorable habitat in the Anthropocene. We determined the genetic differentiation and demographic history of dhole across the tiger reserves of Maharashtra using the microsatellite data of 305 individuals. Simulation-based analyses revealed a 77–85% decline in the major dhole sub-populations. Protected areas have provided refuge to the historically declining dhole population resulting in clustering with strong genetic structure in the remnant dhole population. The historical population decline coincides with the extreme events in the landscape over the past 300 years. The study highlights the pattern of genetic differentiation and diversity of a highly forest-dependent species which can be associated with the loss of forest cover outside tiger reserves. It also warrants attention to develop conservation plans for the remnant surviving population of dholes in India.

The Antarctic and the surrounding Southern Ocean are currently subject to rapid environmental changes and increasing anthropogenic impacts. Seabird populations often reflect those changes and so act as indicators of environmental variability. Their population trends may provide information on a variety of environmental parameters on the scale of years or decades. We therefore provide long-term data on the cape petrel (Daption capense) population from a long-term monitoring program on Fildes Peninsula, South Shetland Islands, Maritime Antarctic, an area of considerable human activity. Our data, covering a period of 36 years, indicate some variability, but no clear trend in the number of breeding pairs between the breeding seasons 1985 and 2006. However, beginning in the 2008 season, the population decreased significantly and reached a minimum in the 2020 season. The mean annual decrease between 2008 and 2020 was 10.6%. We discuss possible causes of this strong negative population trend. Anthropogenic disturbance only affects a few breeding sites in the area and is therefore unable, on its own, to explain the consistent population decline at all the breeding sites studied. We think it more likely that reduced food availability was the main cause of the drastic decline in the cape petrel population.

Far Eastern Curlew Numenius madagascariensis (Linnaeus, 1766) is Endangered species confined in East Asian Australasian Flyway (EAAF) sites. We compiled and summarized all historical numbers of Far Eastern Curlew in Banyuasin Peninsula, South Sumatra, Indonesia. A total of 30 records were documented from 1984 to 2020. The largest number is 2,620 individuals during the migration period in 1988. Unfortunately, the largest number drop to 1,750 individuals in wintering period in 2008, and then drop to 850 individuals in 2019. The numbers indicate that the population decline by up to 62% in the last 35 years (1984 to 2019). It is clear that the global decline of the Far Eastern Curlew also reflects the local population decline in Banyuasin Peninsula.

Kargil lies in the Trans-Himalayan region between 32°15`- 34°56`N latitude and 75°35`- 76°57` E longitude covering a geographical area of 14,086 Km2 has a vast diversity of aromatic and medicinal plants. The traditional uses of medicinal plants to cure various ailments in the Kargil district have been practiced from ancient times. The present study was conducted to validate the information on ethnobotanical studies of some threatened medicinal plants in the region and local people’s perception of its population decline. Therefore extensive field survey was conducted in a different region of district Kargil of Ladakh UT from May 2015- September 2020 to observe the habitat, altitudinal ranges, flowering, traditional uses of threatened medicinal plants, and the factors which are operating for the depletion of these important taxa from their natural habitat. Interviews were conducted in Local languages from more than 1000 informants as the corresponding author is a native of the study area. A total of 22 threatened plant species (21Angiosperms, 1 gymnosperm) belongings to 17 genera, 14 families were traditionally used tribal peoples of the valley to cure various ailments. Most of the threatened taxa belong to the family Ranunculaceae followed by Asteraceae. From local people’s perception, land-use change, illegal exploitation, and the selling of plant parts in the black market are the worst threat to the depletion of these species.Significance Statement: The flora of Ladakh is crying for Conservation due to factors such as climate change, bio-piracy, smuggling, pre maturation harvesting pressure, poverty, unemployment, human interference which leads to their extinction in the near future. Therefore it’s very pertinent to develop conservation strategies and adopt Sustainable utilization practices. For this mass awareness programs on sustainable utilization and conservation of these threatened medicinal plants need to be conducted by involving various stakes-holders, universities, colleges, schools, and other various government and non-governmental organizations.

The interplay between sustainability and anthropogenic landscape transformation is crucial to understanding the past decline and eradication of wild animals. The Bronze Age site of Zaoshugounao is located in the Guanzhong region of China, an area critical in the formation and development of early Chinese civilisation. Drawing upon zooarchaeological, palaeoenvironmental and textual evidence, analysis of sika deer remains from Zaoshugounao reveals sustainable sika deer-hunting strategies at the site, despite an overall long-term trend in the sika deer population decline and habitat loss. The authors’ results highlight the complexity and diversity of human-sika relations and contribute to ongoing discussions surrounding wild animal eradication and conservation in China.

In Japan, population decline is one of the important issues that need to be tackled in socioeconomic fields. We apply an analysis method composed of a spatial autocorrelation analysis to the local population data generated through the 1995 and 2015 national census, and try to detect their spatial dynamics in this study. Through making experimental verification of the distance parameter of the spatial autocorrelation analysis, we newly define 2 indices with respect to the size and area where lower local populations are distributed in urbanized areas. It is shown that the local population dynamics are described by the difference of the 2 indices among 1995 and 2015. The expansion of areas where local population decline occurred seems to be detected by our proposed approach.

Geographical isolation is closely associated with rural population decline and policies for regional and rural development frequently emphasize better transportation infrastructure improvements. Although poor access to jobs and services may lead to negative rates of net migration and skewed age and gender distribution in rural and remote areas, research on the association of road infrastructure improvement with rural demographic dynamics remains sparse. The current study adds to the understanding of these issues by examining the effects of a large-scale road tunnel project in Northern Iceland. The results suggest that improved road infrastructure coincides with a break in long-term population decline through parity in net migration and positive changes in the composition of the population of sparsely populated areas.

SummaryNew Caledonia hosts a large part of the world’s breeding population of the Tahiti Petrel Pseudobulweria rostrata. This rare, cryptic and little-studied seabird nests locally in the mountains up to 1,200 m in altitude, particularly in ultramafic (i.e. nickel-rich) areas where mining activity is a major threat. The considerable development of mining activities in New Caledonia over the past decade raises concerns about its potential impacts on breeding populations through both direct habitat destruction and side effects such as pollution or repeated disturbances. This context calls for a dedicated assessment of the persistence of local populations to guide the design of an adapted conservation strategy and potential restoration programmes. We investigated the impact of mining activities on a Tahiti Petrel population when surveyed pre-mining (2004–2007) and following a period of full mining (2017–2018). The vocal activity was assessed at a total of 114 night-call count stations spread over the Koniambo massif. Areas with ground-originated vocal activity were then searched during daytime for nesting evidence. Finally, georeferenced aerial photos were used to estimate habitat degradation as the percentage of bare soil cover (PBSC) within a 400-m radius around each call count station. Our study revealed a dramatic decline in the Tahiti Petrel vocal activity and a desertion of breeding habitats during the full-mining period compared to the pre-mining period. In light of these results, we recommend designing safe breeding areas and combining restoration methods including social attraction, predation control and artificial burrows at mining sites.

We describe the population of the Еndangered sea otter Enhydra lutris on Urup Island, one of the main wildlife refuges in the southern Kuril Islands of Russia. We reviewed historical and local reports of the sea otter, identified its habitat around the island, and surveyed the coastal waters of the island in 2019. Sea otters were numerous on Urup Island in the past but were hunted excessively and almost exterminated by the 1950s. Since then, sea otter populations have increased, and as the island is almost uninhabited we expected otters to be numerous. This was not the case, and we estimated the total population to be 363 ± SE 126 individuals. Our observation of two skinned carcasses on the shore suggests the low numbers are a result of poaching for the illegal fur trade. The case of Urup Island demonstrates that sea otters require active conservation, as even on a remote island they remain threatened. Establishment of protected areas would be an effective conservation measure for this species, although the suppression of demand for sea otter fur is of the greatest importance.

Background Habitat heterogeneity clearly distinguished in terms of availability of food and habitat resources and landscape features (natural or human-modified) play a crucial role in the avian species composition and population structure. To examine this, a study was carried out in Bhubaneswar, India, to understand the ecological niche distinction in birds based on habitat heterogeneity. Regular sampling was conducted in 30 sampling sites covering six different habitat types in a predominantly urban landscape of Bhubaneswar for understanding the ecological niche in birds. The birds were classified into 11 types of foraging guilds. Results The insectivorous guild had the highest bird species richness (181 species) and the omnivorous guild had the lowest (11 species). The piscivorous guild and wetland habitat had the strongest linkage, followed by the insectivorous guild and agricultural land. The frugivorous guild was significantly correlated with forest habitats (r = 0.386, p < 0.01) and park and garden habitats (r = 0.281, p < 0.01). This urban area hosted a higher number of bird species in certain habitat types, viz., agricultural lands (52%, 115 species) and forest patches (50%, 111 species). Conclusion The present study highlights the importance of agricultural lands, forest patches, parks and gardens, and wetlands inside the cityscape for supporting avifauna. It is therefore suggested that such habitats should be conserved inside an urban area to protect native avifauna. Thus, the city development plan must invariably include strategies for conserving the forest patches inside the urban area. Measures must be taken to restrain the degradation of agricultural lands and reduce their utilization for non-agricultural purposes, which will help in further reducing the bird population decline in the urban landscape.

Tungiasis is a neglected parasitic skin disease, caused by the female sand flea Tunga penetrans penetration, that is associated with poverty and occurs in many poor resourced communities in the Caribbean, South America and Africa. Although its effects on humans and domestic animals are well described in the literature, its epidemiology in indigenous populations remains enigmatic and little is known about the tungiasis impact on wild animals, such as jaguars, the only Panthera genus member on the American continent, an important species as an indicator of environmental integrity, which, in Brazil, is on the list of animals threatened with extinction by the Environment Ministry, categorized as vulnerable. The carnivore population decline in Amazon would be accelerated, especially in the eastern and southern border of the Amazonian domain, and it is known that anthropic factors favor the spread of generalist pathogens to new environments and species, representing a greater risk for wild populations. Thus, ectoparasites identification in jaguars is important not only to understand the role of this feline in maintaining the vectors in the wild, but also to know possible agents that can be transmitted by them. The objective of the present work is to report the tungiasis occurrence in five jaguars run over in Sinop, Sorriso and Lucas do Rio Verde, northern MT, between 2018 and 2020; this being the first scientific report found of parasitism by T. penetrans in jaguars in the Amazon biome. The lesions were found on the animals paws, characterizing phases two to five of the Fortaleza classification, and the infestations were evaluated as high, in the youngest animals, to low, suggesting that parasitism degree would be related to the age of the host.

The Arctic fox (Vulpes lagopus L.) population on the Kola Peninsula occupies an intermediate, and potentially connecting, position between foxes living on the Scandinavian Peninsula and populations further east in Russia, but very little is known about the status of this population. Here we summarize data from the literature, forgotten archival sources about research in the first half of the twentieth century, and the results of several independent expeditions undertaken over the past two decades. These materials include data on fur harvesting, incomplete monitoring data from official winter track counts of game animals, local knowledge, and our own observations. Our research revealed the extremely poor state of the Arctic fox population on the Kola Peninsula. According to our estimates, the current population is likely isolated and consists of no more than a few dozen adults. The fur return data, together with long-term data on small rodent abundance, suggest that irregular and fading out lemming cycles were a major driver of the Arctic fox population decline. The thorough research from the 1930s contrasts strongly with the lack of interest in studying and monitoring the population in recent decades, which is not even listed as a threatened species in the regional Red Data Book. In fact, the work performed here filled a more than a half-century gap in the study of the population and allowed us to determine the urgent need to resume research and immediately take active measures to protect and promote the recovery of the species in the region.

Currently, the Galapagos sea lion (GSL, Zalophus wollebaeki) and Galapagos fur seal (GFS, Arctocephalus galapagoensis) are among the most important endemic species for conservation in the Galapagos Archipelago. Both are classified as “Endangered” since their populations have undergone drastic declines over the last several decades. In this study we estimated the abundance of both otariids, and their population trends based using counts conducted between 2014 and 2018 in all their rookeries, and we analyzed the influence of environmental variability on pup production. The GSL population size in 2018 in the archipelago was estimated to be between 17,000 to 24,000 individuals and has increased at an average annual rate of 1% over the last five years after applying correction factors. The highest number of GSL counted in the archipelago was in 2014 followed by a population decline of 23.8% in 2015 that was associated with the El Niño event that occurred during that year. Following this event, the population increased mainly in the northern, central and southeastern rookeries. The GSL pup abundance showed a decreasing trend with the increase in intensity of the El Niño. The GFS population in 2018 was counted in 3,093 individuals and has increased at an annual rate of 3% from 2014 to 2018. A high number of GFS counted in 2014 was followed by a population decrease of 38% in 2015, mainly in the western rookeries. There was interannual population fluctuations and different growth trends among regions of the archipelago. GSL and GFS pup abundance has a strong decreasing tendency with the increase in the subthermocline temperature (ST) and the El Niño 1 + 2 index. Our results provide evidence that both species are highly vulnerable to periodic oceanographic-atmospheric events in the Galapagos Archipelago which impact prey abundance and the flow of energy in the unique Galapagos ecosystem.

This study examines regional differences in local environment factors to better understand the sustainability of local governments indexed by per capita public spending. Under the condition of heterogeneous population size, we examine how factor characteristics differ depending on the spatial context represented by the urban area category. By employing a Cobb–Douglas cost function with congestion effects on public service provision, the estimated factors enable us to articulate major factors and differences in cost-efficiency between urban area categories. We found that statistical significance and even the signatures of local environment factors differ depending on the urban employment area category. Regarding factors such as the ratios of employees in secondary and tertiary industries, these did not tend to be statistically significant in small-sized urban areas, while small-sized cities in large-sized urban areas were likely to gain confidence intervals. Moreover, we did not observe any statistical significance for the ratio of elderly people due to the balance of spending between national and local governments. These findings could contribute to sustainable management of cities in the advent of population decline.

Amphibians are among the most threatened taxa in the world. Anthropogenic habitat alteration is possibly the most important driver of their population decline and can occur through many different f...

1. As more and more species face anthropogenic threats, understanding the causes of population declines in vulnerable taxa is essential. However, long-term datasets, ideal to identify lasting or indirect effects on fitness measures such as those caused by environmental factors, are not always available. 2. Here we use a single year but multi-population approach on populations with contrasting demographic trends to identify possible drivers and mechanisms of seabird population changes in the north-east Atlantic, using the Atlantic puffin, a declining species, as a model system. 3. We combine miniature GPS trackers with camera traps and DNA metabarcoding techniques on four populations across the puffins’ main breeding range to provide the most comprehensive study of the species' foraging ecology to date. 4. We find that puffins use a dual foraging tactic combining short and long foraging trips in all four populations, but declining populations in southern Iceland and north-west Norway have much greater foraging ranges, which require more (costly) flight, as well as lower chick-provisioning frequencies, and a more diverse but likely less energy-dense diet, than stable populations in northern Iceland and Wales. 5. Together, our findings suggest that the poor productivity of declining puffin populations in the north-east Atlantic is driven by breeding adults being forced to forage far from the colony, presumably because of low prey availability near colonies, possibly amplified by intraspecific competition. Our results provide valuable information for the conservation of this and other important North-Atlantic species and highlight the potential of multi-population approaches to answer important questions about the ecological drivers of population trends. biologging, diet, DNA metabarcoding, dual foraging, foraging ecology, intraspecific competition, population decline, seabirds

Bank Swallow (Riparia riparia) is a declining insectivorous bird that nests colonially in near-vertical surfaces, including natural banks along waterways as well as those created by industrial excavation. Several threats are likely contributing to the population decline, conservation measures have been recommended, and monitoring methods have been developed. However, little is known of this species in the extensive boreal portion of its breeding range. To assess whether recommendations developed in southern areas are likely to be effective in a more northerly region, we investigated aspects of the nesting ecology of Bank Swallow in southern Yukon during 2013–2017. Nesting activity occurred between 20 May and 21 August. We found an exceptional abundance of nest burrows in natural riverbanks along 46 km of the Yukon River near Whitehorse (326 burrows/km), but relatively low percent burrow occupancy in both natural and artificial habitats compared to studies from other regions. Year-to-year persistence of nest burrows and rates of reuse of burrows were high compared to other studies. We highlight the potential importance of the boreal region for recovery of Bank Swallow in Canada, and the importance of using region-specific estimates of percent occupancy when monitoring Bank Swallow using burrow counts. Further study is needed to determine whether unoccupied burrows contribute to nesting success, and whether there are situations in which Bank Swallow burrows should be protected year-round instead of only during nesting.

Previous studies reported that habitat degradation and alteration (e.g., urbanization, agricultural intensification, and abandonment, as well as contaminants) led to frog population decline, which has become a serious global ecological issue. However, the combined effects of midsummer drainage and agricultural modernization on tadpole populations are rarely investigated. In this study, we evaluated the effects of human activity-induced water management and the type of drainage system in paddy fields on the survival of Zhangixalus arboreus in central Japan. Our results revealed that the midsummer drainage negatively affected tadpole survival, whereas the modern drainage system showed no influence. This study provides a useful way to better understand the survival of frog populations in the paddy field ecosystems.

Land crabs are threatened by ocean sprawl even though they act as keystone consumers in coastal forest. Female land crabs must migrate to the sea annually to release larvae. However, they face the risk of road mortality which reduces ecological connectivity. We investigated the spawning migration rhythm and the roadkill of land crab. Migrating crabs and roadkilled crabs were recorded on coastal roads in South Korea from July 28 to August 27 in 2018. Female land crabs mainly released zoeae during spring tide. The number of roadkilled crabs also synchronized with migration peak. A majority (95%) of 739 roadkilled carcasses were female crabs. As a result, the female crabs accounted only 29.6% of the population which can lead to a population decline. The roadkill density was the highest in a residential area without cement guardrails. These results suggest the mitigation actions for land crab roadkill. Among them, prohibiting vehicular traffic between sunset and midnight during spring tides in the breeding season should increase the viability of the population.

SummaryPublic preferences for wildlife protection can dictate the success or failure of conservation interventions. However, little research has focused on wildlife preferences among youth or how youth prioritize species-based conservation. We conducted a study of youth between 7 and 20 years old (n = 128) at five local schools situated near critical hawksbill turtle (Eretmochelys imbricata) nesting beaches in El Salvador to determine their wildlife preferences and how they prioritize species for conservation based on five attributes: endemism; use for hunting and fishing; rapid decline in population size; presence around their home; and ecological significance. These Salvadoran youth showed preferences for native over non-native species and tended to rank rapid population decline as the most important attribute for prioritizing wildlife for protection, followed by use for hunting and fishing. Participants in local environmental education activities placed greater importance on species in rapid decline than non-participants, who considered endemism as most important. Overall, these findings reveal how environmental education may successfully promote increased prioritization of imperilled species among youth. Economic payments for conserving hawksbill turtles may link the two top reasons that Salvadoran youth provided for protecting species by compensating for the reduced hunting required to facilitate population stabilization.

Changing forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally., The nature of forest disturbances are changing, yet consequences for forest dynamics remain uncertain. Using a new index, Stanke et al. show the populations of over half of the most abundant tree species in the western US have declined in the last two decades, with grim implications for how temperate forests globally will respond to sustained anthropogenic and natural stress.

The European eel stock is in a multi-decadal decline. When fishing yield diminished throughout Europe, the small-scaled fyke-net fishery for eel on the west coast of Sweden gradually increased. This contrary trend lasted from the early-1900s, until the 1990s when fishing restrictions eventually limited the catch. We identified the processes driving this aberrant historical development. Using data on the fisheries from 1914 to 2006, we analysed the relation of total landed quantities to stock abundance indices, weather conditions, technical development, and market indicators. No relation between landed volumes and abundance indices was found, but market price (inflation-adjusted) was clearly correlated. Weather and technical development had a minor influence on landed volumes. This indicates that the commercial eel fishery on the west coast developed due to increasing demand and increasing eel prices. We found no evidence that the local stock has been fully exploited, though the increasing catch must have gradually reduced the contribution to the international spawning stock. These results stress the importance of considering economic processes when interpreting historical catch data as a source of information on population size in stock assessments, and ultimately, understanding the collapse of the eel stock.

International audience; Recent estimates indicate that ∼70% of the world’s seabird populations have declined since the 1950s due to human activities. However, for almost all bird populations, there is insufficient long-term monitoring to understand baseline (i.e., preindustrial) conditions, which are required to distinguish natural versus anthropogenically driven changes. Here, we address this lack of long-term monitoring data with multiproxy paleolimnological approaches to examine the long-term population dynamics of a major colony of Leach’s Storm-petrel (Hydrobates leucorhous) on Grand Colombier Island in the St. Pierre and Miquelon archipelago—an overseas French territory in the northwest Atlantic Ocean. By reconstructing the last ∼5,800 y of storm-petrel dynamics, we demonstrate that this colony underwent substantial natural fluctuations until the start of the 19th century, when population cycles were disrupted, coinciding with the establishment and expansion of a European settlement. Our paleoenvironmental data, coupled with on-the-ground population surveys, indicate that the current colony is only ∼16% of the potential carrying capacity, reinforcing concerning trends of globally declining seabird populations. As seabirds are sentinel species of marine ecosystem health, such declines provide a call to action for global conservation. In response, we emphasize the need for enlarged protected areas and the rehabilitation of disturbed islands to protect ecologically critical seabird populations. Furthermore, long-term data, such as those provided by paleoecological approaches, are required to better understand shifting baselines in conservation to truly recognize current rates of ecological loss.

The current status of the red king crab population off western Kamchatka is considered based on data from bottom trawl surveys and fishery statistics since 2013. Some biological parameters of this crab species are provided; its commercial stock is estimated; some features of red king crab fishery and determination of total allowable catch for the past 7 years are analyzed. The red king crab fishing was resumed in 2013 after an 8-year ban imposed due to the population decline. During this period, the stock recovered and reached values greater than those recorded before the ban: the total estimated size of red king crab population in 2017 was almost 244 million ind., which is the highest value for the recent 17 years of research; the estimated number of commercial-sized males, 110 million ind., has not been recorded from the western Kamchatka shelf for at least past 4 decades. Recently, the Severny Zapretny and Khairyuzovsky areas of the shelf zone have yielded their role of main feeding grounds for pre-recruit crabs and juveniles to the Ichinsky area located south. For the 7 years of red king crab fishery, harvest values have been steadily high. In the past 3 years, the major part of the annual catch of live crabs has been exported to China and South Korea. As the analysis of size structure show, the body size of male red king crabs has been increasing each year all over the shelf. This may be explained by the strict sorting of caught crabs aboard vessels transporting live crabs with the release of the largest individuals; another possible explanation is the relatively low recorded number of pre-recruits in the past 2 years. For the 7 years past (including 2019), the fishing mortality rate is estimated within a range of 5–16% of the crab stock actually recorded from the permitted fishery areas, which is a highly cautious approach. In the nearest future, the crab commercial stock is expected to gradually decrease, which, nevertheless, should not fall below the reference target value of biomass. The current status of the red king crab population off western Kamchatka does not raise concern, and the ongoing intense harvesting of this valuable species within the recommended catch size will not have any negative effect on its commercial stock.

Bumble bees (species of Bombus Latreille, 1802) are important pollinators that are generally in population decline, but species presence and relative abundance are unknown in forested wetlands of the Acadian forest. To address this knowledge gap, we sampled bumble bees in forested wetlands and harvested sites (clearcuts) using vane and pan traps. We collected 617 specimens representing 11 species. We also included observations from iNaturalist (n = 70) in disturbed sites. We found that species-specific abundance in Acadian forested wetlands differed significantly from that in harvested sites. Wet coniferous forests with moderate to high herbaceous cover had greater overall bumble bee abundance than harvest sites. Species interactions may also influence community structure: sites with higher abundance of Bombus borealis Kirby, 1837 and B. ternarius Say, 1837 had fewer B. fervidus (Fabricius, 1798); B. flavidus Eversmann, 1852; and B. terricola Kirby, 1837. Differences in presence and abundance of bumble bee species may be explained by forested wetlands having a greater variety of flowering plants than forest harvest sites.

Significance Understanding the drivers of abundance and biodiversity decline across numerous taxa is imperative for designing conservation policy. We use highly detailed citizen science data to show that there is a strong, robust negative association between bird abundance and ambient ozone concentrations in the United States. In particular, we find that a regulation aimed at reducing ozone precursors has significantly bolstered populations in the eastern United States. Our estimated effects suggest that the large decline in average US ozone concentrations over the past several decades has averted the loss of potentially billions of birds. Environmental policies nominally aimed at humans can also provide substantial benefits to other species.

Agriculture intensification drives changes in bird populations but also in the space use by farmland species. Agriculture in Eastern Europe still follows an extensive farming model, but due to policy shifts aimed at rural restructuring and implementation of government subsidies for farmers, it is being rapidly intensified. Here, we aimed to document the ranging behaviour and habitat use of a declining farmland bird of prey—Montagu’s Harrier—and to compare it to findings from Western Europe. In 2011–2018, 50 individuals were followed with GPS loggers in Eastern Poland to study species spatial ecology. We found home ranges (kernel 90%) to be considerably large: 67.3 (± 42.3) km2 in case of males, but only 4.9 (± 6.1) km2 in females. Home ranges overlapped by 40%, on average, with other males in colonies and by 61%, on average, between consecutive breeding seasons of a particular male. The average daily distance travelled by males and females reached, respectively, 94.5 and 45.3 km, covering a daily home range of 32.3 and 3.1 km2. Individuals foraged up to 35 km from nests (3.5 km on average). Daily distance travelled and daily home ranges varied across the breeding season, in case of females being shortest in July, but sharply increasing in August. Also, individuals with breeding success had higher daily distance travelled but smaller daily home ranges. Average harriers’ distance to nest was generally increasing over the season, but was also changing over time of day: birds were closest to nest during night time, but at the end of the season, males roosted up to 16 km from the nest. While foraging males slightly preferred grasslands, higher elevation and smaller land-use patches, they avoided slopes and proximity of roads. We conclude that the surprisingly large home ranges of breeding harriers may suggest reduced prey availability or high fragmentation of hunting areas, both driving birds to utilise large areas and potentially contributing to population decline.

This article advances the discussion of subsidised housing and accessible and walkable neighbourhoods by focusing on the characteristics of cities experiencing population decline. We examine the neighbourhood context of subsidised housing with respect to walkability and accessibility in shrinking cities using Walk Score and a walkability index that considers the unique neighbourhood dynamics in these cities and access to anchor institutions and transit. Our results confirm recent studies that the majority of HUD units are in less walkable neighbourhoods and with low access to anchor institutions. Our results support the inclusion of more refined walkability and accessibility measures in affordable housing siting criteria. These measures would encourage the development of revitalisation strategies with enhanced walkability, services and transit.

Lithuania is a post-communist country that has experienced a rapid population decline. This study examines one of the largest cities in Lithuania, Siauliai, regarding urban shrinkage in the post-co...

All seahorse species (genus Hippocampus) are listed under Schedule I of India's Wild Life Protection Act, making all capture and trade of seahorses illegal. In the more than 15 years since the ban, little work has been done to assess its effects on seahorse conservation. Between 2015 and 2017, fisheries and trade surveys were conducted along the south‐east coast of India, in the state of Tamil Nadu, historically known to be a hub for seahorse catches and trade. Seahorses were primarily landed as bycatch, although in greater quantities by traditional drag nets than as trawl bycatch. Total annual catches were estimated between 4.98 million and 13.64 million seahorses, 87% of which were caught by active non‐selective gear. Generalized additive models revealed that seahorse catch per unit effort had non‐linear relations with depth and latitude, and were higher in biogenic habitats, with active, bottom‐used, and non‐selective gears (e.g. trawls). The illegal nature of the trade in seahorses hampered an understanding of trade routes and trade volumes. Catch estimates indicated that 11.21–30.31 tonnes of seahorses probably entered trade, yet interviews with traders only documented trade of about 1.6 tonnes. Fishers reported a decreasing availability of seahorses. Since most seahorses come from bycatch in persistent fisheries that are not directly affected by the ban on seahorse capture, this decline is likely to represent a population decline. A fishery and trade ban for incidentally caught species, particularly in a poorly regulated fishery, appears to add little conservation value. There needs to be a shift in the management approach, moving from a ban towards spatial and temporal restrictions, and toward enforcing existing fishery regulations.

The yellow-throated bulbul (YTB) is an endemic passerine restricted to scrub forests along hill slopes with exposed rocky outcrops in the Deccan Peninsula, India. It is found in small, discontinuous populations and is vulnerable to extinction due to ongoing habitat loss and subsequent population decline. To assess the genetic connectivity and past demography, we sequenced 1050 nucleotide base pairs of the mitochondrial control region of 60 individuals that represent distinct populations in the geographic range of the species. We recovered 39 haplotypes defined by 81 variable sites. Haplotype diversity was high with low nucleotide diversity, suggesting rapid population growth from a founder population with a small effective population size. The negative values of Tajima’sDand Fu’sFsand small positive value of Ramos-Onsins and Rozas’R2suggest deviation from neutrality and population expansion. The haplotype network and demographic expansion parameters further suggest historical population expansion. Mismatch analysis statistics and Bayesian skyline plots estimate population expansion during the late Pleistocene. Although the species presently occurs in small, disconnected we found no structuring of the population. Dispersal events are the most likely explanation for the absence of genetic structuring in the YTB population. These results represent important data for the design of a conservation plan for this endemic and globally threatened species.

Aldabra giant tortoises (Aldabrachelys gigantea) are currently listed as Vulnerable on the IUCN Red List of Threatened Species. However, negative impacts of sea-level rise are predicted to result in an overall population decline of 40-65 % over the next 100 years, rendering the species Endangered. Captive propagation is an important tool for in- and ex-situ species conservation, but breeding success outside the tortoises’ native island habitats has been very limited. Until now, the reproductive cycle of Aldabra tortoises has only been described in anatomic and behavioural studies. During a one-year period, plasma of four female and four male wild tortoises on Aldabra Atoll were examined monthly for levels of gonadal steroid hormones (oestradiol, testosterone, progesterone). Plasma oestradiol and testosterone values as well as meteorological data of the sampling period corresponded to previously published reports on seasonal changes in anatomy, behaviour and climate on the Aldabra Atoll. Seasonal changes in plasma testosterone were evident in males, with high values from January through April, reflecting previously described testicular growth and breeding season, followed by a nadir in August and September. In females, plasma oestradiol levels displayed seasonal changes, coinciding with reported ovarian growth from January to May. The obtained data provide prerequisite knowledge for endocrinological monitoring of reproductive processes and management of breeding programs, both ex-situ as in-situ, to establish reserve- and rewilded populations.

The waterbuck (Kobus ellipsiprymnus), though widespread throughout Africa, is suspected to be declining overall. Data on population numbers and structure are lacking for many parts of its range, especially in West Africa, where the subspecies defassa is found. The aim of the present study was to evaluate the abundance, distribution and attributes of waterbuck populations from the Nazinga Forest Reserve, southern Burkina Faso. We investigated waterbuck population trends in the park using transect data collected in 1985–2019. For the more detailed analyses of population structure and distribution of the animals, we used census data gathered during 2019. Most animals were adults (46.6%), and the sex ratio was heavily skewed towards females (5:1). Most animals were concentrated along the larger rivers. There was no influence of poacher activity on waterbuck distribution. In the long term (1985–2019), the population dynamics of waterbuck can be roughly divided into two main periods: a phase of population increase from 1985 to 2005, and one of ongoing population collapse from 2007 to 2019. Although the declining population trend was obvious, coefficients of determination were low indicating that the years explained poorly the number of individuals and the number of sightings obtained. Waterbuck numbers in the Nazinga Forest Reserve are declining, but we found no single reason to explain this trend. It is likely that a combination of factors, including global warming (increased aridity) and illegal activities such as poaching, is responsible. Because there are probably multiple reasons for the observed waterbuck population decline in our study area, we suggest that a multifaceted approach should be adopted in order to enhance the conservation status of the local waterbuck populations.

Knowledge about the demographic histories of natural populations helps to evaluate their conservation status, and potential impacts of natural and anthropogenic pressures. In particular, estimates of effective population size obtained through molecular data can provide useful information to guide management decisions for vulnerable populations. The spotted ragged-tooth shark Carcharias taurus (also known as the sandtiger or grey nurse shark) is widely distributed in warm-temperate and subtropical waters, but has suffered severe population declines across much of its range as a result of overexploitation. Here, we used multilocus genotype data to investigate the demographic history of the South African C. taurus population. Using approximate Bayesian computation and likelihood-based importance sampling, it was found that the population underwent a historical range expansion that may have been linked to climatic changes during the late Pleistocene. There was no evidence for a recent anthropogenic decline. Together with census data suggesting a stable population, these results support the idea that fishing pressure and other threats have so far not been detrimental to the local C. Taurus population. The results reported here indicate that South Africa could possibly harbour the last remaining, relatively pristine population of this widespread but vulnerable top predator.

The European eel is a highly threatened species according the European Inland Fisheries Advisory Commission (EIFAC) and the Food and Agriculture Organization of the United Nations (FAO). The recruitment of this species has collapsed over the last fifty years primarily because of the destruction of free migration routes and overfishing. One of the most important factors linked to population decline is mortality during catadromous migration caused by hydroelectric facilities. The aim of the present study was to assess the mortality rate of silvers eel passing through two small hydroelectric facilities. Total mortality at the site was 5%, but it was 15% for fish passing through the two hydroelectric facilities. However, the cumulative mortality in the river basin studied, which has many hydroelectric facilities, indicated that silver eel escapement from the Słupia drainage basin was very low.

This article deals with the problem of extinction of Russian municipalities, namely Russian villages, villages and cities. The authors noted the main reasons for the population decline. The opinions of scientists on this issue are considered separately. A comparative analysis of the current situation in Europe and the United States. The strategies of rural development in Russia and abroad are touched upon. As a result of the study, concepts were identified that give ideas about what needs to be done to restore the disappeared territories.