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Few ecosystems are more sensitive to hydrological change than seasonally-flooded wetlands. Here, we investigate how changes in hydrological regimes caused by the construction of two dams have contributed to large changes in the structure and dynamics of the Kafue Flats, an internationally-important, partially-protected wetland ecosystem in Zambia. We use historical (1970) and contemporary (2013) data to describe changes in hydrology due to dam operations, and to compare the areal extent, distribution, and composition of the major wetland and dryland habitats in the pre- and post-dam periods. To understand the seasonal dynamics of the ecosystem and how these dynamics influence the seasonal movement and use of the ecosystem by the dominant grazing herbivore, the endangered Kafue lechwe, we combine data on annual hydrological variation with spatially- and/or temporally-explicit quantitative estimates of: (1) grass biomass and nutrient stocks, (2) distribution of lechwe across habitats, and (3) lechwe nutritional status. The operation of the dams has reduced hydrological variation, causing a loss of more than 50% of seasonally-flooded grasslands and probably promoting woody encroachment in some habitats. Our results demonstrate that Kafue lechwe is highly dependent on these seasonally-flooded grasslands during the dry season, when their nutritional status is otherwise critically low. In combination, we hypothesize that changes in the flooding regime driven by dam construction precipitated ecosystem-level changes that—together with other factors—may have contributed to a rapid historic, as well as ongoing decline in the lechwe population. Our study highlights potential consequences of the spatio-temporal homogenization of a previously highly variable ecosystem.Highlights: Temporally-variable hydrological conditions drive ecosystem structure and dynamics. Water regulation restructures an internationally-important wetland ecosystem. Ecosystem changes contribute to the decline of an endangered migratory herbivore. [ABSTRACT FROM AUTHOR]

Deciphering how natural selection emerges from demographic differences among genotypes, and reciprocally how evolution affects population dynamics, is key to understanding population responses to environmental stress. This is especially true in non-trivial ecological scenarios, such as programmed cell death (PCD) in unicellular organisms, which can lead to massive population decline in response to stress. To understand how selection may operate on this trait, we exposed monocultures and mixtures of two closely related strains of the microalga Dunalliela salina, one of which induces PCD, to multiple cycles of hyper-osmotic shocks, and tracked demography and selection throughout. Population dynamics were consistent between mixtures and monocultures, suggesting that selection on PCD does not involve strong ecological interactions. The PCD-inducing strain was maintained throughout the experiment despite an initial decline, by a combination of fast population rebound following each decline, and density-dependent competition dynamics near the stationary phase that were independent of these initial population fluctuations. As a result of PCD maintenance, population decline in response to environmental stress was not counter-selected in our experiment, but persisted over 13 cycles of salinity. Our results highlight how analysing the demographic underpinnings of fitness and competition can shed light on the mechanisms underlying selection and eco-evolutionary dynamics. [ABSTRACT FROM AUTHOR]

Introduction: Climate change poses a significant threat to bird communities, especially forest-dwelling and narrowly distributed species, which are expected to experience severe range contractions and higher extinction risks compared to widely distributed and open-area species. The Chocó region in southwestern Colombia, known for its rich bird endemism, is particularly vulnerable. Methods: We analyzed potential distribution shifts for 27 endemic and near-endemic bird species in the Chocó region using eBird occurrence records and climate projections. We modeled species distributions under low and high greenhouse gas emission scenarios for 2050 and 2070, comparing these projected distributions to current forested and protected areas to evaluate future conservation needs. Results: Our findings indicate that nearly all species are projected to lose climate-suitable areas under at least one future scenario, resulting in a regional decline in species richness. Changes in species richness are most pronounced near the Colombia-Ecuador border, suggesting a shift to higher elevations. Notably, the Scarlet-and-white Tanager (Chrysothlypis salmoni) is predicted to suffer the greatest losses in climate-suitable area, both within protected and forested regions. Discussion: These results highlight the urgency of expanding the protected area network and conserving key forested regions to help species adapt to climate change. By providing projected distribution maps and potential range shifts, our study underscores the importance of modeling future distributions to support conservation strategies for at-risk species and the ecological services they provide in tropical montane regions. [ABSTRACT FROM AUTHOR]

Examining the interdependencies between internal migration and national population decline in Japan, this paper begins by analysing the impacts of internal migration on national fertility decline, for example, through the early post‐World War II flows from high‐fertility countrysides to low‐fertility cities. It then focuses on the way in which, in the context of national population decline, internal migration exacerbates the problems facing Japan's rural areas by adding population loss and, in particular, the loss of young adult populations, to the mounting problems of public and private‐sector disinvestment, job losses, ageing (both social and physical) and the abandonment of land use and built form. [ABSTRACT FROM AUTHOR]

[Display omitted] • The San Miguel Island fox (SMIF) is a new host and range record for Pachysentis canicola. • Pachysentis canicola causes intestinal damage, necrosis, peritonitis, and death in SMIFs. • SMIFs had poorer body condition and lower weight after the parasite was first detected. • SMIFs are inherently vulnerable to stochastic events and P. canicola might exacerbate this risk. In the late 1990s, the San Miguel Island fox (Urocyon littoralis littoralis) faced near-extinction. Fourteen of the 15 remaining foxes were placed into an island-based captive breeding program used to repopulate the island. Although the fox population in San Miguel reached pre-decline numbers by 2010, a second decline started around 2014, coincidental with a newly observed acanthocephalan parasite. To identify this introduced acanthocephalan species and determine the pathologic consequences of its infection on the health of foxes, we used an extensive record of island fox necropsies and associated parasite collections. In addition, we used detailed fox capture-recapture data to investigate population health and demographic trends of foxes before and after parasite emergence. We identify the parasite as Pachysentis canicola, a common acanthocephalan in mainland foxes in North America. The parasite was detected in 69% of the necropsied foxes from San Miguel Island and was not found in any of the other five Channel Island fox subspecies. Health impacts attributed to the acanthocephalan parasite, including erosive and ulcerative enteritis, transmural necrosis, and inflammation, were described in 47% of the foxes infected with the acanthocephalan. Despite infection with various other helminth parasite species, body condition remained good and the mortality rate low in San Miguel Island foxes until the arrival of the acanthocephalan. Body condition improved after 2018, perhaps due to increases in rainfall following a drought, but remained 27% lower than the pre-acanthocephalan period, which suggests that environmental conditions and parasitism jointly drive fox population dynamics. [ABSTRACT FROM AUTHOR]

The Harbison's dun skipper subspecies (Euphyes vestris harbisoni) has a geographically limited distribution in southern California, USA and northern Mexico, isolated from the other subspecies. This skipper is a specialist, primarily found in riparian oak woodlands and only feeds on the San Diego sedge as a larva. Several extirpations have been documented, generating concern for its long-term persistence. We conducted visual surveys in 2021 and 2022, and a marking study in 2022, to assess population sizes. Habitat preferences were explored by collecting habitat covariates and analyzing GIS available environmental data. A significant decline in skipper counts occurred during a drought, with abundances remaining small following the drought. Population size estimates from a marking study had low accuracy due to the small population sizes. For this reason, we used the annual maximum count (Max Count) as a robust and efficient metric for monitoring this skipper. No difference was found between used and unused sedge patches using vegetation-based habitat covariates. However, a GIS approach described the historic distribution as woodlands at intermediate elevations, warmer summer temperatures, and intermediate levels of summer evapotranspiration. Implications for insect conservation: The decline in abundance and number of populations justify future conservation efforts, including identifying areas that should be prioritized for future surveys and restoration efforts. Most importantly, this study demonstrates that these woodlands should be managed/protected in their entirety to allow for annual movement of sedge plants and skippers. [ABSTRACT FROM AUTHOR]

The carpsuckers (Carpiodes spp.) are a little-studied genus within the Ictiobinae, a subfamily of Catostomidae that also includes the buffalofishes (Ictiobus spp.). Both quillback Carpiodes cyprinus and river carpsucker C. carpio were recently discovered to live in excess of 40 years in Minnesota, and this prompted interest in their study in Colorado. We collected 162 Carpiodes from northeastern Colorado from 2021 to 2023 and identified 143 as quillback, 15 as river carpsucker, and 4 unidentified fingerlings using a suite of morphological characters. No single character worked to separate and identify the two species in all cases. Cluster analysis helped identify six specimens where examination of the suite of characters did not allow identification to the species level. We extracted otoliths for age analysis from 159 individuals to quantify age-score precision, size at age, recruitment dynamics, and sexual maturity. Ages were very precise for both species with evidence of longevity near a half century (quillback 49 years, river carpsucker 40 years) as well as pronounced asymptotic growth. We also found that otolith mass explains significant variation in Carpiodes age, and can be used to predict quillback and river carpsucker age in Colorado. In addition, Colorado quillback mature larger and earlier than populations assessed in other regions. Finally, the historic database of Carpiodes in Colorado reveals range contraction as well as decades of skewed size structure indicative of long-lived species. Clearly, this long-neglected group of fishes requires further study, including genetic analyses to explain and validate systematics of this genus. Management attention is also needed across the declining range of this genus because their life histories are longer-lived and more complex than previously realized. [ABSTRACT FROM AUTHOR]

Rattans are climbing palms, known for strong flexible canes and are important Non-Timber Forest Products in south and southeast Asian countries. Of the five rattan genera, Calamus holds a pivotal position owing to huge local and global market demand. A substantial part of these NTFPs is harvested from the natural populations, leading many economically exploited rattans to the verge of extinction. The present work intended to study the consequences of population decline on the genetic diversity parameters of four economically exploited threatened Calamus species (C. brandisii, C. acanthospathus, C. nambariensis and C. andamanicus) distributed in the three geographical zones of India. The study generated a draft genome of C. brandisii of 848.89 Mb size, which has been used to develop microsatellite markers. Population genetic analysis revealed deviations from Hardy-Weinberg proportions and an excess of heterozygosity, which were interpreted as indicators of small population size combined with obligatory outcrossing, stemming from population decline. Distinct populations with strong genetic structures were identified along with evidence for genetic bottlenecks. The existing ex-situ populations of C. acanthospathus and C. nambariensis have been found inadequate for representing and conserving the available gene pool in the wild. Through MAXENT modeling, highly suitable ecological niche were predicted for C. brandisii. Conservation and management plans, both in-situ and ex-situ need to prioritize the protection of genetically unique populations. In light of the observed sex skewness in rattan populations, augmentation programs should focus on safeguarding mature individuals, enhancing population size and age structure, and monitoring and balancing the sex ratio in wild populations. [ABSTRACT FROM AUTHOR]

Crop rotation has been a commercial practice for managing the sugarbeet cyst nematode (Heterodera schachtii, SBCN) since the 1950s. Research conducted in southern California established that SBCN populations decline at the rate of 49% to 80% per year, leading to estimates that three- to four-year rotations to nonhost crops would be sufficient to reduce SBCN densities to nondamaging levels. Following grower reports that much longer rotations were needed in central California, trials were conducted to establish the rate of decline of SBCN in the San Joaquin Valley. Ten commercial fields with a history of SBCN infestation were sampled periodically for up to 6.3 years. In each field, 10 circular subplots located 30.5 meters apart (each with a 6-m radius) were established with reference to a permanent landmark. On each sampling date, 12 subsamples from each subplot were taken randomly from the top 0 cm to 30 cm of soil and composited into a single sample. Standard techniques were utilized to extract and count cysts and eggs from soil samples. Average yearly rates of population decline in the sampled fields ranged from 11.4% to 25.8%. This finding has implications for SBCN management in California sugarbeets grown for biofuel, as the lower decline rates indicate that longer nonhost rotation periods than previously anticipated may be necessary.

The objective of this research was to describe the variation in breeding practices in the population of Arabian horses in Algeria in relation to the population size drop observed in the 2000s, due to an increase in the cost of food and a change in interest in racing, related to the black decade. As a result, the breeders had to face two opposite constraints: enhancing reproduction to counter the population decline and preventing the loss of genetic diversity. The aim of the study was to evaluate the genetic consequences of the decisions taken over a period of 30 years, starting from 1988 to 2018. The study was based on the analyses of the stud-book and on 11 microsatellite markers in a group of 943 horses, distributed into 13 age classes. Between 2004 and 2008, the breeders purchased foreign sires and dams, allowing a relative stability in unbiased heterozygosity of about 71%, due to the high genetic distances between foreign and local horses. As these importations stopped from 2009 on, there was a decrease in allele numbers of about 20%. Moreover, from 2010 on, we observe an excess of inbreeding and an increase in genetic drift relative to the starting population, due to population size decline. From the analysis of genetic distances between local individuals, it seems that the only constraint for sires and dams allowed to mate was a null coefficient of inbreeding.

According to the monthly counts of the Wetland Bird Survey (WeBS), the numbers of Eurasian Oystercatchers Haematopus ostralegus wintering in Great Britain has gradually decreased since the late 1980s/early 1990s. Although numbers also decreased in the South West region of England, the decline was much steeper in the Exe estuary population, suggesting that site-specific pressures may have affected this species in this regionally-important Special Protection Area. By combining data from the WeBS with those from 45 years of research on Oystercatchers by the Centre for Ecology and Hydrology, we tested five hypotheses that could explain the relative decline on the Exe estuary: (1) a gradual improvement in estimating Oystercatcher numbers as counting methods were refined, (2) a deterioration in the main food supply, the Blue Mussel Mytilus edulis, (3) disturbance from people on and alongside the estuary, (4) disturbance from Peregrine Falcons Falco peregrinus and (5) an as yet unexplained increase in the frequency of stealing of mussels from Oystercatchers (kleptoparasitism) by Carrion Crows Corvus corone and European Herring Gulls Larus argentatus. The data are consistent only with the fifth hypothesis. Individual-based modelling suggested that kleptoparasitism at the increased frequency that occurred on the Exe estuary could have reduced the foraging success of Oystercatchers sufficiently to have (1) reduced the overwinter survival of the numerically dominant mussel-eating adults and (2) deterred prospecting immatures from choosing the estuary as their future wintering site. [ABSTRACT FROM AUTHOR]

Urban shrinkage has emerged as a worldwide concern, which is increasingly prevalent in developing countries like China, particularly in medium-sized cities (MSCs). Compared to large cities and counties, MSCs find themselves in a national policy blind spot and have been neglected both in policy and research. Previous studies, based on population changes, have shown that urban shrinkage in China is not severe. However, urban shrinkage is not just about population decline, and it has not been adequately discussed from a multi-dimensional perspective. This paper adopts a multi-dimensional model, considering population, economy, and space dimensions to analyze shrinkage patterns in 164 MSCs in China from 2010 to 2020. Findings reveal that 6.1% of MSCs experienced population shrinkage, and 24.4% faced shrinkage in economic or spatial dimensions. Shrinking MSCs are spatially distributed in the Northeast as well as in the areas surrounding large cities. Industrial restructuring, job losses, and healthcare disparities contribute to urban shrinkage, and the impact of aging will be further felt. As large cities consistently attract population and resources and digitization has dramatically affected population mobility, more MSCs will shrink in the future. This paper contributes to the understanding of shrinkage of MSCs among scholars and policymakers, urging a shift towards more balanced and digital urban governance. [ABSTRACT FROM AUTHOR]

Bordoibam-Bilmukh is a small wetland located at the boundary of the Dhemaji and Lakhimpur districts of Assam, India that provides shelter and breeding ground to many resident and migratory birds. A survey was conducted between October 2022 and March 2024 on the avian diversity of Bordoibam-Bilmukh Bird Sanctuary. A total of 47 bird species under 16 orders and 29 families were recorded during the survey. Order Passeriformes, recorded with the highest number of avian species (15). Among the families, the highest number of species (5) was recorded under Ardeidae. Out of all the species recorded, three species, viz., Brown Shrike, Citrine Wagtail, and White Wagtail were winter migratory; one species, the Lesser Kestrel, was summer migratory, and the remaining 43 were resident species. Besides, two species, viz., Lesser Adjutant and Greater Adjutant are listed as 'Near Threatened' species on the IUCN Red List. Comparing the avian diversity from 1997 to 2024, a decline in the number of avian species from 167 (as per the 1997 record) to 47 (as per the present study) has been observed in the sanctuary. Various anthropogenic activities such as habitat destruction and disturbance, hunting of birds, are the major causes of the decline of avian diversity. For future species diversity restoration in the sanctuary, these negative anthropogenic activities should be addressed immediately for conservation strategies. [ABSTRACT FROM AUTHOR]

Bumblebees are a genus of pollinators (Bombus) that play important roles in natural ecosystem and agricultural production. Several bumblebee species have been recorded as under population decline, and the proportion of species experiencing population decline within subgenus Thoracobombus is higher than average. Bombus opulentus is 1 species in Thoracobombus, but little is known about its recent population dynamics. Here, we employed conservation genomics methods to investigate the population dynamics of B. opulentus during the recent past and identify the likely environmental factors that may cause population decline. Firstly, we placed the scaffold‐level of B. opulentus reference genome sequence onto chromosome‐level using Hi‐C technique. Then, based on this reference genome and whole‐genome resequencing data for 51 B. opulentus samples, we reconstructed the population structure and effective population size (Ne) trajectories of B. opulentus and identified genes that were under positive selection. Our results revealed that the collected B. opulentus samples could be divided into 2 populations, and 1 of them experienced a recent population decline; the declining population also exhibited lower genetic diversity and higher inbreeding levels. Genes related to high‐temperature tolerance, immune response, and detoxication showed signals of positive selection in the declining population, suggesting that climate warming and pathogen/pesticide exposures may contribute to the decline of this B. opulentus population. Taken together, our study provided insights into the demography of B. opulentus populations and highlighted that populations of the same bumblebee species could have contrasting Ne trajectories and population decline could be caused by a combination of various stressors. [ABSTRACT FROM AUTHOR]

Population decline due to low fertility and aging causes socioeconomic challenges such as a shrinking labour force and regional decline. In response to these challenges, there is a growing discussion about accepting immigrants to mitigate the side effects of population decline. This implies the importance of analyzing local peoples' perceptions as a basis of policy and planning in anticipation of demographic transitions toward a multicultural society. While there are many studies on local problems caused by depopulation and perceptions of immigrants based on contact theory and group threat theory, there has been relatively little research on the relationship between depopulation and individual perceptions of immigrants. This study fills this gap by using survey data of Seoul, Korea, the city experiencing both population decline and an increase in immigrants. It employs the multilevel ordered logit model to explore how the decrease in local population associates with individuals' perception on the need for multicultural immigration policies. The results suggest that individuals are more likely to have a positive view of multicultural immigration policies if their region is experiencing a higher population decline. This finding is significant as it demonstrates that a shift to an unfavourable demographic structure can have a positive impact on perceptions of immigrant acceptance, offering a new perspective on the relationship between immigrants and native residents. [ABSTRACT FROM AUTHOR]

Introduction: Hopea hainanensis Merrill & Chun is considered a keystone and indicator species in the tropical lowland rainforests of Hainan Island. Owing to its high-quality timber, H. hainanensis has been heavily exploited, leading to its classification as a first-class national protected plant in China and a plant species with extremely small populations (PSESPs). Methods: This study analyzed genome-wide single nucleotide polymorphisms obtained through restriction site-associated DNA sequencing from 78 adult trees across 10 H. hainanensis populations on Hainan Island. Results and discussion: The nucleotide diversity of the sampled populations ranged from 0.00096 to 0.00138, which is lower than that observed in several other PSESPs and endangered tree species. Bayesian unsupervised clustering, principal component analysis, and neighbor-joining tree reconstruction identified three to five genetic clusters in H. hainanensis, most of which were geographically widespread and shared by multiple populations. Demographic history analysis based on pooled samples indicated that the decline in the H. hainanensis population began approximately 20,000 years ago, starting from an ancestral population size of approximately 10,000 individuals. The reduction in population size accelerated approximately 4,000 years ago and has continued to the present, resulting in a severely reduced population on Hainan Island. Intensified genetic drift in small and isolated H. hainanensis populations may contribute to moderate differentiation between some of them, as revealed by pairwise Fst. In conclusion, our conservation genomic study confirms a severe population decline and an extremely low level of nucleotide variation in H. hainanensis on Hainan Island. These findings provide critical insights for the sustainable management and genetic restoration of H. hainanensis on Hainan Island. [ABSTRACT FROM AUTHOR]

Farmland habitats witness steep declines in biodiversity. One rapidly declining farmland species is the ortolan bunting Emberiza hortulana. In Finland, a staggering 99% of the population has been lost during the past 30 years. Changes in the breeding habitats have been proposed as a reason for the decline, although hazards during migration and wintering may also play a role. We gathered a 19‐year data set of Finnish ortolan buntings and studied which spatial characteristics, habitat features, and climate factors might explain the population growth rate at the singing‐group level. As explanatory variables we used region, density of small‐scale structures, proportion of agricultural area in the landscape, diversity of crop types, proportion of bare ground, and temperature and precipitation of previous breeding season. Higher population growth rates were associated with higher crop type diversity and higher proportion of bare ground. The mosaic of various crop plants and bare ground may provide a wider array of feeding, hiding and nesting places, and an easier access to food. Higher growth rates were also associated with landscapes dominated by interconnected agricultural land, which may reflect the species' sociability and avoidance of forested areas. The North Ostrobothnia region had higher growth rates compared to other regions. We suggest that northern populations of ortolan bunting should be targeted for further studies on feeding and breeding ecology as well as for urgent conservation actions, such as increasing crop type diversity and bare ground. [ABSTRACT FROM AUTHOR]

Anthropogenic impact has transitioned from threatening already rare species to causing significant declines in once numerous organisms. Long‐tailed duck (Clangula hyemalis) and velvet scoter (Melanitta fusca) were once important quarry sea duck species in NW Europe, but recent declines resulted in their reclassification as vulnerable on the IUCN Red List. We sequenced and assembled genomes for both species and resequenced 15 individuals of each. Using analyses based on site frequency spectra and sequential Markovian coalescence, we found C. hyemalis to show more historical demographic stability, whereas M. fusca was affected particularly by the Last (Weichselian) Glaciation. This likely reflects C. hyemalis breeding continuously across the Arctic, with cycles of glaciation primarily shifting breeding areas south or north without major population declines, whereas the more restricted southern range of M. fusca would lead to significant range contraction during glaciations. Both species showed evidence of declines over the past thousands of years, potentially reflecting anthropogenic pressures with the recent decline indicating an accelerated process. Analysis of runs of homozygosity (ROH) showed low but nontrivial inbreeding, with FROH from 0.012 to 0.063 in C. hyemalis and ranging from 0 to 0.047 in M. fusca. Lengths of ROH suggested that this was due to ongoing background inbreeding rather than recent declines. Overall, despite demographically important declines, this has not yet led to strong inbreeding and genetic erosion, and the most pressing conservation concern may be the risk of density‐dependent (Allee) effects. We recommend monitoring of inbreeding using ROH analysis as a cost‐efficient method to track future developments to support effective conservation of these species. [ABSTRACT FROM AUTHOR]

The Caucasian Parsley Frog, Pelodytes caucasicus (Boulenger, 1896), is endemic to Caucasia, and its population is decreasing. Here, we present information on the genetic structure and diversity of populations from four provinces of Türkiye (Giresun, Trabzon, Rize, and Artvin) using microsatellite markers. Despite their small geographic range, the species' populations showed moderate genetic differentiation, which could be a result of rapid genetic drift. Our results show that Trabzon and Giresun populations are genetically different from those of Rize and Artvin. We found considerably low genetic diversity in Artvin, Trabzon, and Giresun populations. The inbreeding co-efficient is also high in those localities (HO

This study first examines changes in the amount of residential area on a regional scale, which is said to shrink following population decline, using Japan as an example, where population decline is already underway in most of the country. Second, it examines how the regional governments have set future targets for residential areas and whether these targets are consistent with the current trend. Third, it examines how prefectures, Japan's regional governments, are responding to this situation through regional land use planning. The methodologies of the paper are a combination of collecting and sorting out the related data, reviewing and extracting information from planning documents, and conducting interviews with persons in charge. In conclusion, residential areas have continued to increase on a regional scale, even as the population has declined. Shrinkage does not follow population decline on a regional scale. It was also found that the amount of residential area changed more closely with the change in households than with the population. National and regional land use plans generally set targets for more shrinkage than the actual trend. The underestimation of the amount of residential area was due to the rapid decline in the number of persons per household. Cases of the three prefectures showed that specific control is left to the individual acts, while the measures are indicated in the wording by the prefectural land use plans. [ABSTRACT FROM AUTHOR]

Abstract Background Many municipalities in rural areas of Korea are facing population decline due to the aging population phenomenon. This study examined the relationship between residing in municipalities facing population decline and satisfaction with nearby healthcare infrastructure in older aged adults. Methods The 2021 Korea Community Health Survey (KCHS) data were used. Municipalities were classified as those not facing population decline, those at risk, and those facing population decline based on the Population Decline Index. The association between residing in municipalities facing population decline and satisfaction with nearby healthcare infrastructure was examined cross-sectionally using a multi-level logistic regression analysis. Satisfaction with available public transportation was concomitantly examined as it is related to accessing healthcare services. Results Of the 58,568 individuals aged 65 years or above analyzed, 27,471 (46.9%) adults were residing in municipalities without population decline, 4,640 (7.9%) adults in municipalities at risk of population decline, and 26,457 (45.2%) in municipalities with population decline. Individuals living in municipalities with population decline were more likely to be dissatisfied with nearby healthcare infrastructure (OR 1.76, 95% CI 1.41–2.20). Similar tendencies were found for public transportation infrastructure (OR 1.67, 95% CI 1.38–2.03). Conclusions Individuals residing in municipalities with declining populations are more likely to report dissatisfaction with nearby healthcare infrastructure and public transportation. These findings emphasize the importance of providing adequate medical infrastructure to reduce potential health-related disparities.

The myxoma virus species jump from European rabbits (Oryctolagus cuniculus) to Iberian hares (Lepus granatensis) has raised concerns. We assess the decline suffered by Iberian hare populations on the Iberian Peninsula and discuss the association between the effect of myxomatosis and the average abundance index, which we estimated by using hunting bags.

Foundation species, such as trees, corals, grasses, oysters, and rockweeds, must be common and abundant to effectively modify the physical environment and increase biodiversity by buffering environmental stress. Yet many of these important species have been declining due to disease, climate change, and other factors. A prime example is the precipitous population decline of marine rockweeds, which is attributed to increased urbanization and its accompanying impacts. Rockweeds provide three-dimensional habitat in harsh rocky intertidal environments and regulate ecosystem functioning, essential roles that no substitute species are capable of filling. Recovery of impacted rockweed populations is typically slow and unpredictable due to their limited dispersal capacity. These issues have motivated efforts to conserve remaining populations of rockweeds and reestablish or enhance depleted ones. Successfully doing so requires a robust understanding of factors that affect survival of the species and the processes that influence ecosystem structure, along with rigorous scientific testing of restoration methods and the factors that affect restoration success. In this comprehensive review, we summarize the current knowledge of rockweed ecology, highlight studies that could inform restoration practices, and recommend ways to improve our ability to implement scalable restoration of rockweeds and accompanying ecosystem-wide benefits.

Despite the numerous food studies conducted in Detroit, none have assessed changes in the food landscape over a decade. No previous study has systematically analyzed food store closures in the city either. We will address these oversights by examining the distribution of food outlets in the city ten years apart. This paper probes the following questions: (1) How has the distribution of Detroit's food outlets changed in the decade between 2013 and 2023? (2) Does Detroit fit the definition of a food desert in 2013 or 2023? (3) Does Detroit fit the definition of a food swamp in 2013 or 2023? (4) Has supermarket redlining occurred in Detroit in 2013 or 2023? (5) How is population decline related to food outlet distribution? (6) How do food store closures impact food store distribution? We conducted exhaustive searches to collect information on thousands of food outlets from Data Axle, Google, and Bing. The data were analyzed and mapped in SPSS 28 and ArcGIS 10.8. We compared 3499 food outlets identified in 2013 with 2884 identified in 2023. We expanded our search for food outlets in 2023 and found an additional 611 food outlets in categories not studied in 2013. The study's findings are significant as they unearth evidence of extensive population decline—driven by Black flight—and a vanishing food infrastructure. Detroit lost more than 600 food outlets between 2013 and 2023, a staggering number that underscores the severity of the issue. Moreover, in 2023, we documented food store closures and found 1305 non-operational or closed food outlets in the city. Regardless of the neighborhood's racial composition, the household median income, or the educational attainment of residents, food store closures were widespread in 2023; 27.3% of the food outlets identified that year were defunct. Despite the massive food store closures, Detroit did not fit the description of a food desert; each of the city's 54 neighborhoods had between 7 and 300 food outlets. The food swamp thesis did not accurately describe the city either, as supermarkets/large grocery stores were intermingled with convenience and corner stores in both study periods. The data did not find evidence of supermarket redlining, as supermarkets/large grocery stores were found in formerly redlined neighborhoods alongside dollar stores and variety stores in both study periods. [ABSTRACT FROM AUTHOR]

The introduced Japanese weasel, Mustela itatsi, has had a significant negative impact on indigenous terrestrial vertebrates across several islands in the Miyako Group. The present study aimed to assess the current population status of squamate reptiles by investigating the distributions and abundances of three endangered lizards, Plestiodon kishinouyei, Takydromus toyamai, and Emoia atrocostata atrocostata, on Shimojijima Island and Irabujima Island. Route censuses for these species were conducted in the periods from 30 July to 4 August and 8–13 October 2022. Additionally, opportunistic sightings of lizards outside of the designated censuses were recorded. Eight P. kishinouyei, 20 T. toyamai, and seven E. a. atrocostata were recorded along four out of 101 survey routes, six out of 76, and two out of 39, respectively, with one additional E. a. atrocostata sighting at a non-census site. Plestiodon kishinouyei and E. a. atrocostata exhibited highly restricted distribution: the former was exclusively found in the northwestern part of Shimojijima Island, whereas the latter was confined to the southwestern part, with no presence on Irabujima Island. Takydromus toyamai was observed on both Shimojijima Island and Irabujima Island. The frequency of occurrence was low for the two skink populations on Shimojijima Island and T. toyamai on Irabujima Island, suggesting a potential population decline. These findings provide baseline data on the population status of these three lizard species. Such data will be crucial for evaluating their prospects for recovery, particularly considering the ongoing extensive eradication project targeting the introduced Japanese weasel on these islands. [ABSTRACT FROM AUTHOR]

Records from online biodiversity databases (including citizen science data) can play a crucial role in enhancing scientific knowledge about the abundance, distribution, and population trends of poorly studied species which are usually not properly monitored. This study aims to demonstrate the utility of data hosted in GBIF in detecting the likely decline of species common and widely distributed in the past, but whose conservation status is now uncertain, such as the weasel (Mustela nivalis) in Spain. To address this, we analyzed data on its presence in Spain from 2008 to 2022 available on GBIF.org, and compared it with the distribution data from the Atlas of Mammals of Spain published in 2007. The results indicate that: (i) data from GBIF.org reveal a moderate decline (negative trend) in the weasel population in Spain during the study period; (ii) the species has been recorded in a limited number of 10 × 10 km UTM-squares (Universal Transverse Mercator) within its distribution range as defined by the 2007 atlas; and (iii) there are large areas of Spain in which the species has not been detected in recent years. These findings highlight the concerning conservation status of this carnivorous species and underscore the value of data from open access platforms such as GBIF in identifying potential silent extinctions. [ABSTRACT FROM AUTHOR]

The current Japanese Regional Revitalisation policy emerged from a unique combination of demographic, geographical and socio-economic challenges to address growing disparities between urban and rural areas. This is due to the over-concentration of population and economic activities in Tokyo and other metropolitan areas, combined with the out-migration of the youth from lagging regions, especially, young females. In response to a call for international comparative policy research and analysis to tackle similar societal challenges, this paper analyses the policy contexts of the Japanese Regional Revitalisation and the UK Levelling Up agendas. It highlights a series of place-based industrial policy measures in Japan over the last decades illustrated by two local case studies of city-regions. The Japanese decentralisation process may be unique as it presents a form of top-down transfer of industrial policies to local governments including innovation and start-up supports. The decentralisation must be accompanied by adequate funding and fiscal autonomy, enabling local and regional governments to manage their own resources. [ABSTRACT FROM AUTHOR]

Background: Many municipalities in rural areas of Korea are facing population decline due to the aging population phenomenon. This study examined the relationship between residing in municipalities facing population decline and satisfaction with nearby healthcare infrastructure in older aged adults. Methods: The 2021 Korea Community Health Survey (KCHS) data were used. Municipalities were classified as those not facing population decline, those at risk, and those facing population decline based on the Population Decline Index. The association between residing in municipalities facing population decline and satisfaction with nearby healthcare infrastructure was examined cross-sectionally using a multi-level logistic regression analysis. Satisfaction with available public transportation was concomitantly examined as it is related to accessing healthcare services. Results: Of the 58,568 individuals aged 65 years or above analyzed, 27,471 (46.9%) adults were residing in municipalities without population decline, 4,640 (7.9%) adults in municipalities at risk of population decline, and 26,457 (45.2%) in municipalities with population decline. Individuals living in municipalities with population decline were more likely to be dissatisfied with nearby healthcare infrastructure (OR 1.76, 95% CI 1.41–2.20). Similar tendencies were found for public transportation infrastructure (OR 1.67, 95% CI 1.38–2.03). Conclusions: Individuals residing in municipalities with declining populations are more likely to report dissatisfaction with nearby healthcare infrastructure and public transportation. These findings emphasize the importance of providing adequate medical infrastructure to reduce potential health-related disparities. [ABSTRACT FROM AUTHOR]

Kaghaznagar and Sironcha Forest Divisions in the Deccan Plateau of India support large breeding colonies of critically endangered species of long-billed Gyps indicus (LBV) and white-rumped G. bengalensis (WRV) vultures. To assess their abundance and age-structure, that are important population parameters, they were surveyed every month at their breeding colonies; LBV at Palarapu cliff during 2010–2021 and Lakkameda cliff during 2015–2021, and WRV at Dechilpeta during 2014–2021. Breeding colonies of LBV supported a mean of 32 ± 1.3 individuals during 2015–2021. Although its number increased from 34 individuals in 2015 to 42 in 2017, it declined significantly to 10 in 2021. In contrast, WRV with a mean of 49 ± 3.35 individuals between 2014 and 2021 increased from 22 to 66. Data on the population structure show that adults constitute bulk of the population in both LBV (78 ± 1.2%) and WRV (80 ± 2.1%) with a low proportion of young age-classes of sub-adults, juveniles and chicks. With a declining trend and low proportion of young-age classes, the LBV breeding colonies are likely to decrease over time. Although WRV showed an increasing trend during the study period, the high adult proportion (80%) cannot guarantee its sustained growth. [ABSTRACT FROM AUTHOR]

One of the most pressing socio-economic issues across EU countries has been the depopulation of a significant part of its territory. Less urbanized areas are perceived as non-attractive places to live and have been losing population steadily in the latest decades. For the case of Spain, this European-wise phenomenon has been exacerbated for several territories characterized by a large presence of primary and extractive industries in the past. We quantify empirically the contribution that the closure of the heavily subsidized coal mining had on the depopulation trends experienced in mining-intensive areas in Spain. This poses an interesting research question, since both non-mining and mining territories in Spain suffered a remarkable negative down trend in demographic terms since early nineties, which was the period on which the coal mining industry started to cease steadily its activity. Our empirical strategy relies on matching estimators that compare the demographic trend across mining-intensive and non-mining intensive municipalities in four provinces, controlling for observable characteristics and isolating the net effect of the “shock” originated by the termination of this mining activities. Our analysis finds a statistically significant and sizable negative effect on the fall of population for mining-intensive municipalities between 1991 and 2011.

IntroductionClimate change poses a significant threat to bird communities, especially forest-dwelling and narrowly distributed species, which are expected to experience severe range contractions and higher extinction risks compared to widely distributed and open-area species. The Chocó region in southwestern Colombia, known for its rich bird endemism, is particularly vulnerable.MethodsWe analyzed potential distribution shifts for 27 endemic and near-endemic bird species in the Chocó region using eBird occurrence records and climate projections. We modeled species distributions under low and high greenhouse gas emission scenarios for 2050 and 2070, comparing these projected distributions to current forested and protected areas to evaluate future conservation needs.ResultsOur findings indicate that nearly all species are projected to lose climate-suitable areas under at least one future scenario, resulting in a regional decline in species richness. Changes in species richness are most pronounced near the Colombia-Ecuador border, suggesting a shift to higher elevations. Notably, the Scarlet-and-white Tanager (Chrysothlypis salmoni) is predicted to suffer the greatest losses in climate-suitable area, both within protected and forested regions.DiscussionThese results highlight the urgency of expanding the protected area network and conserving key forested regions to help species adapt to climate change. By providing projected distribution maps and potential range shifts, our study underscores the importance of modeling future distributions to support conservation strategies for at-risk species and the ecological services they provide in tropical montane regions.

That anti-predator behavior can have large demographic consequences (called risk effects) is theoretically well-founded and experimentally supported. Here we investigate whether this mechanism could be contributing to population declines reported over recent decades for many shorebird species, especially long-distance migrants. Sandpipers are known to have adjusted behavioral and morphological traits to counter the migratory danger posed by the increase in abundance of an important predator, the Peregrine Falcon ( Falco peregrinus ), ongoing steadily since the mid-1970s. Individuals in some shorebird species skip migration and breeding (over-summer), remaining instead on or near non-breeding areas. Over-summering can be considered an anti-predator tactic because it avoids all exposure to predators during migration, though at the expense of a foregone breeding season. We hypothesize that over-summering by the Semipalmated Sandpiper ( Calidris pusilla ) has increased during recent decades as migration became more dangerous. A stage-structured matrix population model based on survival rates measured in Perú 2011–2017 indicates that Semipalmated Sandpiper population growth is negative at current over-summering levels (adults 19%, yearlings 28%). A substantial proportion of the large reduction in their numbers since 1980 could theoretically be accounted for if over-summering levels rose to this level after ~1980. Though good data are scanty, the historical level of over-summering appears to have been lower. The powerful ecological effects of apex predators have been recognized in many systems, but to date the recovery of falcon populations has not been considered as a possible factor in shorebird declines. Closer scrutiny of this hypothesis is warranted.

In the last thirty years, the countries of south-eastern and eastern Europe have experienced significant population decline, and Croatia is no exception to that. This paper revisits the problem of depopulation in Croatia in the last two intercensal periods (2001-2011 and 2011-2021). The aim was to analyze the impact of emigration on depopulation in Croatia and investigate whether it had a greater impact on depopulation than natural decrease. Additionally, the aim was to investigate whether the number of emigrants was underreported in the official statistics. The results show that Croatia lost more population due to negative net migration than the official statistical data indicate. Recent migrations in Croatia did not only affect the population decline, but also age composition of the population, particularly in the last intercensal period due to emigration of families with children and population in their working and reproductive ages, as they composed a large proportion of emigrants. The paper provides an elaborate insight into the recent migration patterns in Croatia while highlighting the underestimation of the proportions of emigration from Croatia by the official statistics. [ABSTRACT FROM AUTHOR]

The McKay's Bunting (Plectrophenax hyperboreus) is endemic to Alaska, breeds solely on the remote and uninhabited St. Matthew and Hall islands (332 km2) in the central Bering Sea, and is designated as a species of high conservation concern due to its small population size and restricted range. A previous hypothesized population estimate (~2,800 to 6,000 individuals) was greatly increased (~31,200 individuals) after systematic surveys of the species' entire breeding range in 2003, establishing McKay's Bunting as one of the rarest passerines in North America. In 2018, we replicated the 2003 surveys and used density surface models to estimate breeding season densities, distributions, and population change over the intervening time period. Our results indicate that the McKay's Bunting population declined by 38% (95% CI: 27 to 48%) from ~31,560 to 19,481 individuals since 2003. Spatial model predictions showed no areas with an increase of birds on either St. Matthew or Hall islands but revealed declines across 13% (42 km2) of St. Matthew Island. Declines disproportionately occurred both in marginal habitats with reduced rocky nesting substrate and in high-density hotspots along the coast of St. Matthew Island. The total area occupied by breeding adults decreased by 8%, and high-density hotspots shifted inland from the coast of St. Matthew Island to higher elevations on both islands, the latter potentially responses to exceptionally warm weather and reduced spring snow cover in 2018. Additionally, we observed low numbers of predators and interspecific competitors in 2018, suggesting that these did not cause the decline. Our findings indicate that McKay's Bunting meets international standards for elevating its conservation status from Least Concern to Endangered based on the International Union for Conservation of Nature Red List of Threatened Species ranking criteria. Additional population monitoring and studies to identify the causal mechanisms of the recent population decline of this rare species could assist future population assessments. [ABSTRACT FROM AUTHOR]