Population Decline Research Articles

An Update on the Conservation Status Assessment of two Endangered Freshwater Mussel Species in Bavaria, Germany

ABSTRACTThe two highly endangered European mussel species Margaritifera margaritifera and Unio crassus are target species of conservation. Based on a recently completed systematic state‐wide monitoring of each 22 M. margaritifera and 22 U. crassus streams in Bavaria, Germany, we present an update on population trends, conservation status, habitat quality and threats for both species. Populations status and habitat quality varied strongly between M. margaritifera and U. crassus streams, but there was also great variability within each of those groups. The population decline of M. margaritifera has continued, albeit higher proportions of juveniles originating from artificial breeding programmes have been established in some streams. Habitat quality often did not match known requirements as evident from poor stream bed quality, lack of hosts and elevated nutrient levels. In contrast, U. crassus populations showed a better status, with an increase in population size over all sampled streams. Successful recruitment was indicated by high proportions of juveniles. However, no mussels older than 16 years were found, probably due to predation and structural stream maintenance measures. Climate change effects, such as extreme droughts, affected both species. This study demonstrates different needs in conservation management for both species. Although mitigation of drought effects is commonly needed for both species, tackling host fish management and direct threats such as predation should be prioritized in U. crassus, whereas restoration of prime habitat quality and intact catchments is key to enable natural recruitment and sustainable populations of M. margaritifera.

Population monitoring and conservation implications of intra- and interspecific nest occupation rates in swallows.

With the exception of a few groups of birds, such as large raptors and colonial seabirds, direct counts of nests cannot be conducted over very large areas for most of the abundant and widely distributed species, and thus indirect methods are used to estimate their relative abundances and population sizes. However, many species of the Family Hirundinidae (swallows and martins) build their mud nests in discrete, predictable and accessible sites, which are reused across years. Therefore, the direct count of active nests could constitute a reliable method for estimating breeding population sizes and their changes at large spatial and temporal scales. We illustrate the feasibility of this monitoring approach through a single year survey of >2700 nests of three coexisting Old-World species, the barn swallow (Hirundo rustica), the red-rumped swallow (Cecropis daurica), and the crag martin (Ptyonoprogne rupestris), distributed across Portugal and Spain. Our results revealed changes in the use of nesting substrates and increases in interspecific nest usurpation rates over recent decades. While 56% of the nests of C. daurica were located in rocks five decades ago, almost 100% are nowadays located in anthropogenic substrates such as bridges, road culverts, and abandoned buildings, which could have favored the range expansion of this species. Nest occupation rates were surprisingly low (12% in C. daurica, 21% in H. rustica, and 37% in P. rupestris), and the proportion of abandoned nesting sites was very high (65% in C. daurica, 50% in H. rustica, and 27% in P. rupestris). Abandonment rates reflect the population decline reported for H. rustica. Notably, the usurpation of nests of C. daurica by house sparrows Passer domesticus, which is the main cause of breeding failure, has increased from 2.4% in 1976-1979 to 34.7% of the nests nowadays. The long-term monitoring of nests may constitute a reliable and affordable method, with the help of citizen science, for assessing changes in breeding population sizes and conservation threats of these and other mud-nest building hirundines worldwide.

Hybridization and inbreeding affect the survival of a critically endangered coral.

Coral reefs face escalating pressures leading to unprecedented declines in the populations of reef-building corals.1,2 Conservation genomic studies are critical in understanding and formulating interventions to reverse such declines but thus far have only focused on a handful of broadcast-spawning species in shallow waters.3,4 The recent International Union for Conservation of Nature (IUCN) reclassification of six different brooding corals as "critically endangered"5 indicates that such species are equally threatened. However, we lack a thorough understanding of the factors underlying their decline. Here, we comprehensively examine the genetic impacts of a severe population decline in the brooding coral Helioseris cucullata, once a major contributor to Caribbean reefs but now critically endangered.6,7,8 Genome-wide sequencing of colonies across five locations revealed the presence of two distinct species, indicating that the remaining population sizes are even smaller than previously estimated. Using an exhaustive, spatially explicit sampling approach (across a total of ∼2.5 hectares), we observed extremely low genetic diversity and identified how localized dispersal, excessive inbreeding, and prevalent asexual reproduction may contribute to an extinction vortex. However, we also found evidence for recent hybridization and introgression, providing an avenue for the reintroduction of genetic diversity into both lineages. With many brooding species now under threat, these results highlight the critical need to assess the genetic processes associated with their declines so that these can be harnessed or mitigated to deliver effective conservation outcomes.

Ecological success of no-take marine protected areas: Using population dynamics theory to inform a global meta-analysis.

Adaptively managing marine protected areas (MPAs) requires accurately assessing whether established MPAs are achieving their goals of protecting and conserving biomass, especially for harvested populations. Ecological MPA assessments commonly compare inside of the MPA to a reference point outside of and/or before implementation (i.e., calculating "response ratios"). Yet, MPAs are not simple ecological experiments; by design, protected populations interact with those outside, and population dynamic responses can be nonlinear. This complicates assessment interpretations. Here, we used a two-patch population model to explore how MPA response ratios (outside-inside, before-after, and before-after-control-impact [BACI]) for fished populations behave under different conditions, like whether the population is receiving a sustainable larval supply or if it is declining despite protection from harvest. We then conducted a Bayesian evaluation of MPA effects on fish and invertebrate populations based on data collected from 82 published studies on 264 no-take MPAs worldwide, using the results of an earlier global meta-analysis as priors. We considered the effects of calculating different summary metrics on these results, drawing on the theoretical insights from our population model as a comparative framework. We demonstrate that not all response ratio comparison types provide the same information: For example, outside-inside and BACI comparisons can fail to detect population decline within MPAs, whereas before-after comparisons likely detect that pattern. Considering these limitations, we nonetheless found that MPAs globally are producing positive outcomes, with on average greater biomass, density, and organism size within their boundaries than reference sites. However, only a small portion of studies (18 of 82) provided the temporal data necessary to determine that protection, on average, has led to increased abundance of populations within MPAs over time. These findings demonstrate the importance of considering the underlying system dynamics when assessing MPA effects. Assuming that large outside-inside or BACI response ratios always reflect large and net positive conservation effects may lead to misleading conclusions, we recommend that: (1) when assessing specific MPA effects, empirical findings be considered alongside theoretical knowledge relevant to that MPA system, and (2) management should respond to the local conditions and outcomes, rather than a blanket expectation for positive MPA effects.

Evaluating the effects of nest management on a recovering raptor using integrated population modeling

AbstractEvaluating population responses to management is a crucial component of successful conservation programs. Models predicting population growth under different management scenarios can provide key insights into the efficacy of specific management actions both in reversing population decline and in maintaining recovered populations. Bald eagle (Haliaeetus leucocephalus) conservation in the United States has seen many successes over the last 50 years, yet the extent to which the bald eagle population has recovered in Arizona, an important population within the Southwest region, remains an area of debate. Estimates of the species' population trend and an evaluation of ongoing nest‐level management practices are needed to inform management decisions. We developed a Bayesian integrated population model (IPM) and population viability analysis (PVA) using a 36‐year dataset to assess Arizona bald eagle population dynamics and their underlying demographic rates under current and possible future management practices. We estimated that the population grew from 77 females in 1993 to 180 females in 2022, an average yearly increase of 3%. Breeding sites that had trained personnel (i.e., nestwatchers) stationed at active nests to mitigate human disturbance had a 28% higher reproductive output than nests without this protection. Uncertainty around population trends was high, but scenarios that continued the nestwatcher program were less likely to predict abundance declines than scenarios without nestwatchers. Here, the IPM‐PVA framework provides a useful tool both for estimating the effectiveness of past management actions and for exploring the management needs of a delisted population, highlighting that continued management action may be necessary to maintain population viability even after meeting certain recovery criteria.

Rational cuts? The local impact of closing undersized schools

The availability of public education services can influence residential choices. Therefore, policies aimed at ‘rationalising’ service provision by reducing the number of undersized nodes in the public school network can lead to population decline, especially in spatially isolated areas lacking valid alternatives to the removed services. This paper examines the demographic and income effects of primary school closures by exploiting an Italian education reform that resulted in the contraction of the school network. We assess whether school closures impact households’ residential choices, over and above preexisting negative population trends that motivate school closures. Our findings indicate that municipalities affected by school closures experience significant reductions in population and income. The effect is primarily driven by peripheral municipalities located far away from economic centres and distant from the next available primary school. This evidence indicates that school ‘rationalisation policies’, by fostering depopulation of peripheral areas, have an influence on the spatial distribution of households and income, thus affecting territorial disparities.

Rural depopulation in Kazakhstan: mechanisms of regulation

The aim is to analyze depopulation trends in rural regions of Kazakhstan, including Kostanay region, and to propose mechanisms for their optimization. Methods - comparative analysis and dynamic methods were used to identify the main causes and annual decline in population in rural areas. Empirical methods were used to determine the factors of rural population reduction, as well as the formation of a system of complex regulation of demographic and social problems. The assessment of socio-economic indicators of the oblast was carried out on the basis of the evaluation approach. Results - the authors note that despite a number of existing documents on the development of rural areas of the country, since 2009 depopulation of the rural population of the country persists. In 2024 compared to 2008 the quantitative composition decreased by 9.1%. It is most characteristic for Kostanay region. In order to more deeply study the depopulation orientation in this region a comparative analysis of social parameters of 4 densely populated and 4 least densely populated areas, including data for the period from 2010 to 2023 was carried out. Conclusions - labor market indicators of Kazakhstan and Kostanay region are somewhat lower compared to urban indicators. In 2023, the labor force participation rate was observed to be higher in rural areas compared to urban areas, but the employment rate was significantly lower. Self-employed workers are 16% more in rural areas and 9% more in the oblast. The low size of income and its stable sources led to the outflow of economically active groups from villages to large cities. In order to comprehensively regulate these processes in rural areas, it is advisable to create an effective mechanism of social responsibility of business (SRB), which will reduce budget expenditures of the state.

Effects of a recent volcanic eruption on the isolated population of the iconic red-billed chough in La Palma, Canary Islands.

The effects of volcanic eruptions on ecosystems, particularly on oceanic islands, have been widely studied because of their important role in land formation, climate patterns and biological processes. Although these phenomena can lead to habitat loss, population decline and even species extinction, their effects on isolated populations, especially vertebrates, are not fully understood due to the paucity of pre-eruption data and in situ observations. Here, we assess the impact of the recent eruption of the Tajogaite volcano in La Palma, Canary Islands, on a unique population of red-billed choughs (Pyrrhocorax pyrrhocorax), an emblematic bird species that symbolises the natural heritage of the island. Pre- and post-eruption surveys showed that the eruption did not significantly affect the overall size or distribution of the population, although the number of choughs decreased after the eruption in the northern and central roosts, and increased in the southern ones. Although the eruption resulted in the release of toxic gases and ash, the observed changes in chough distribution and numbers could be attributed to environmental variability and the use of different foraging areas by individuals rather than direct effects of the volcano. The high mobility of choughs may have allowed them to avoid the negative effects of the volcano in the immediate aftermath of the eruption. Future studies are recommended to assess the long-term effects of volcanic ash on feeding habitats and the possible accumulation of contaminants, such as heavy metals, in the food chain. This will allow not only to monitor the presence of these compounds in ecosystems, but also to understand the response of this species to environmental changes and ensure its conservation.

Black grouse (Lyrurus tetrix) population status, reasons for decline and potential conservation measures from Western and Central Europe to Fennoscandia: a literature review

The long-term decline of the black grouse population throughout Europe is influenced by many factors that affect populations differently depending on the distribution range, from Central Europe to the Scandinavian countries. Therefore, we analyzed available literature sources to describe the main reasons for the population decline of this species and to suggest conservation measures. In total, 228 pieces of literature from 1955 to 2024 were analyzed for this study. Based on the literature analysis, it is clear that the drivers of population decline differ across the distributional range. In Central Europe, where the population is declining rapidly, habitat loss and forest fragmentation are crucial factors, as is the negative impact of tourism. In Scandinavia, where the population is gradually declining, decreasing breeding success and increasing chick mortality rates are generally considered the main negative factors. However, these factors also affect black grouse populations in Central Europe. It is crucial to acknowledge that a significant proportion of the contributing factors, such as predation and habitat loss, can be attributed to human activities. Therefore, it is necessary to emphasize that environmental protection should work hand in hand with wildlife managers to improve the situation.

두뇌 유입(Brain Gain) 관점에서 외국인 유학생의 국내 고용 활성화를 위한 IPA 분석 : 정부출연연구기관 이공계 석·박사과정을 중심으로

With Korea's total fertility rate recorded at 0.72 in 2023, there is even a pessimistic prospect that it will become the 'first country to extinguish the population'. In the face of serious demographic challenges such as a population decline, regions disappear, and a lack of high-quality human resources in the industry due to a rapid decline in the fertility rate, the Korean government and each local government are pouring out various policies to alleviate these problems by utilizing the capabilities of international students. This study analyzed the importance of domestic employment promotion activities and differences in the degree of implementation of the employment support system for international students studying as master's and doctoral students at government-funded research institutes using the importance-performance analysis(IPA) methodology. As a result of the analysis, 'recommendation of supervisors' and 'industrial cooperation projects' were evaluated as the most important employment promotion activities, and in the employment support system, 'flexible visa system' and 'simplification of immigration procedures' for researchers were recognized as important. In addition, it was found that there is a difference in perception between the importance and performance of international students depending on the region of residence and country of origin, so a strategy for promoting employment tailored to the region of residence and country of origin is necessary. This study is limited to international students in science and engineering who are enrolled in U graduate university, so there is a limit to the generalization of research results. In future research, extended research is needed including international students from science and technology specialized universities and base national universities. In addition, it is proposed to expand the study on how the expectations and demands of the employment support system of international students differ according to the cultural context by comprehensively considering the country and cultural background and economic conditions that affect the employment activation of international students.

Mitochondrial Genome of Endangered Hylobatidae, Hylobates agilis and Hylobates lar, of Peninsular Malaysia

Hylobates agilis and Hylobates lar, members of the family Hylobatidae, are classified as endangered species in Malaysia due to threats such as population decline and habitat loss. The aim of this study was to sequence and characterize the mitochondrial genome of H. lar and H. agilis. This study reported the total length of mitogenome of H. agilis and H. lar to be 16,473 and 15,949 base pair (bp), respectively. Each sequence contained 13 protein-coding sequences, 2 rRNAs, 22 tRNAs, and a control region D-loop (H. agilis); meanwhile for H. lar, there are 13 protein-coding sequences, 2 rRNAs, 19 trNAs, and a control region D-loop. Phylogenetic analysis showed both species formed a strong monophyletic clade within Hylobates grouping. Mitogenomic data of this study is essential for future references in evolutionary biology and conservation management of endangered Malaysian gibbons in captivity.

Comparative time series analysis of Anatolian water buffalo stock in Türkiye

Water buffalo holds an important place in the livestock heritage in Türkiye. In the current study, buffalo numbers between 2023 and 2032 were estimated by using buffalo number data from 1991 to 2022. In the study, FAOSTAT data between 1961 and 2021 and TÜİK data for 2022 were used to obtain the time series. ARIMA modeling method was used in the study conducted in R programming language. ARIMA is a time series model that can make predictions from time series based on explaining univariate data. According to the results of the analysis made in the study, it is seen that the number of buffaloes in Türkiye will continue to decrease. According to the results obtained, it is estimated that the number of buffaloes will be 157,755 heads in 2023, 96,851 heads in 2027 and 19,136 heads in 2032. The disease resistance of buffaloes, their high adaptability, the high demand for water buffalo products, the preference for high-yielding cows for milk production despite government support payments, increasing mechanization, the reduction of buffalo habitats and the increase in input costs have led to a decline in Anatolian water buffalo populations. To prevent the Anatolian water buffalo from being threatened with extinction, the population decline must be halted and improved. To ensure this, the decline of the pastures that form the buffalo’s habitat must be halted, pasture areas must be increased, and existing pastures rehabilitated, government subsidies for buffalo and calf rearing must be increased and market opportunities for buffalo products must be expanded.

Estimates of Effective Number of Breeders Identify Drivers of Decline in Mid-Atlantic Brook Trout Populations.

Brook Trout (Salvelinus fontinalis) populations have experienced marked declines throughout their native range and are presently threatened due to isolation in small habitat fragments, land use changes, and climate change. The existence of numerous, spatially distinct populations poses substantial challenges for monitoring population status (e.g., abundance, recruitment, or occupancy). Genetic monitoring with estimates of effective number of breeders (N b) provides a potentially powerful metric to complement existing population monitoring, assessment, and prioritization. We estimated N b for 71 Brook Trout habitat units in mid-Atlantic region of the United States and obtained a mean N b of 73.2 (range 6.90-493). Our modeling approach tested whether N b estimates were sensitive to differences in habitat size, presence of non-native salmonids, base flow index, temperature, acidic precipitation, and indices of anthropogenic disturbance. We found significant support for three of our hypotheses including the positive influences of available habitat and base flow index and negative effect of temperature. Our results are consistent with presently observed and predicted future impacts of climate change on populations of this cold-water fish. Importantly, these findings support the use of N b in population assessments as an index of relative population status.

북유럽 초·중 통합운영학교(Comprehensive School)의 특성 연구

Purpose: Due to the decline in school-age populations and urbanization, the discussion on integrated elementary and middle schools has begun in earnest. To effectively operate integrated schools, it is necessary to refer to the experiences of countries that have long implemented similar systems. Thus, this study aimed to explore the comprehensive school system in Northern Europe, where primary and lower-secondary schools are integrated, and analyze its characteristics to draw implications for the operation of integrated elementary and middle schools in the South Korean context. Methods: To achieve the research objectives, this study examined and analyzed the background and current status of the comprehensive school systems in Northern European countries—Finland, Norway, Sweden, and Estonia—that operate under a single structure integrating the primary and lower-secondary school education periods. The study also explored the teacher training systems, school evaluations, and student assessments in these countries. Results: The four countries aimed to achieve both social welfare for all citizens and educational effectiveness. The comprehensive school systems in each country share a common feature of striving to realize the values of social democracy. To link the two school levels, each country has developed its own teacher training and evaluation systems. Conclusion: These findings suggest that, in order to effectively operate integrated elementary and middle schools in the Korean context, it is essential to develop methods that link and integrate the two school levels while considering the specific characteristics of each level, promote collaboration among teachers, and clearly establish educational objectives in addition to administrative and economic goals.

Mitigating the Problem of Local Extinction through Pilot Operation of the Gyeongbuk Theme City: Focusing on a comparative analysis between Kawaba Village and the Bu-Ul-Gyeong megacity†

As of 2023, over half of South Korea's 228 regions face population extinction, despite substantial local government efforts. This study examines why the "Busan-Ulsan-Gyeongnam (Bu-Ul-Gyeong) Megacity" initiative failed to address this issue. By analyzing the successful revitalization of Kawaba village in Japan, which attracted more than 2.5 million tourists, this study proposes an innovative solution tailored to South Korea—the "Gyeongbuk Four Seasons Theme Park." This project aims to revitalize the Gyeongbuk region's economy and reverse population decline, contributing to Sustainable Development Goal 11: "Sustainable Cities and Communities."This study uses a comparative case study methodology to analyze the Bu-Ul-Gyeong Megacity initiative and Kawaba Village. Data collection involved a review of policy documents and academic literature for the former and fieldwork, including interviews and observations, for the latter. The key participants included local government officials and employees in Kawaba Village. Insights from Kawaba were applied to design the "Gyeongbuk Four Seasons Theme Park," which integrates successful elements from Kawaba's model while addressing the shortcomings of the Bu-Ul-Gyeong initiative.The Bu-Ul-Gyeong initiative failed because of a lack of economic revitalization planning, insufficient community engagement, and poor cooperation between governments. Kawaba village succeeded in establishing partnerships, fostering local enterprises, and maintaining effective government communication. These factors are critical in overcoming challenges in regional development.This study proposes the "Gyeongbuk Four Seasons Theme Park," a rotating, seasonal attraction across four cities, emphasizing local specialties and resident participation. This project aims to increase population inflow and establish sustainable agricultural enterprises, contributing to the economic revitalization of the Gyeongbuk region.

Decoding Socio-Economic Demographic Trends: The Power of Spatial Econometrics and Geographic Analysis

Greece is experiencing a steady population decline caused by the declining migratory and natural balance. This research investigates the spatial impact of socio-economic and demographic factors on the natural population balance in Greece for the spatial zoning of municipal administrative units. Using geographically weighted regression (GWR) on data from the 2011 Greek census, the research explores the local impacts of factors like housing repair permits, vacant housing, employment rates, population inflows, distance from regional centers, aging, gender ratios, and education levels. An initial ordinary least squares (OLS) regression was conducted, revealing significant spatial variation and emphasizing the necessity of spatial econometric methods. The GWR model proved to be more effective in accounting for the variance in the data, removing spatial autocorrelation and revealing high local variation. Results show the high negative impact of the aging index in Western Greece and the Ionian islands, the counterintuitive positive effect of the gender ratio in urban areas, and the positive influence of population inflows in high-migration regions like Northern Greece and Crete. The results of this study underline the need to utilize spatial econometric methods for a precise and detailed understanding of demographic trends and provide valuable insights for localized strategies to address demographic challenges.

PRODUCTIVITY OF PURSE SEINE FISHING TOOLS OPERATING IN THE WATERS OF OUTER AMBON BAY, MALUKU.

The decline in fish populations can negatively impact the livelihoods of fishermen and local food security. Therefore, maintaining the sustainability of fisheries is an urgent necessity. Evaluating the productivity of purse seine catches in the outer waters of Ambon Bay is crucial in this context. This study aims to measure the productivity level of purse seine fishing gear and identify the factors that influence it. The research was conducted from June 2023 to May 2024 in Laha Village, Outer Ambon Bay, Ambon Island. The research method used is a quantitative descriptive method, which aims to describe the productivity of purse seine fishing gear in detail based on data obtained in the form of graphs and tables. Data collection was carried out through field surveys and direct observations during fishing activities. The data analysis results showed that the highest volume and number of trips were in November, with 18 trips and a production volume of 644 kg/trip, while the lowest was in May, with 12 trips and a production volume of 184 kg/trip.

Analysis of land use changes and soil erosion using the EPM-IntErO model in the Sokobanja Basin, Serbia

Soil erosion, with the progressive loss of fertile topsoil and its negative impact on agricultural productivity, has become a critical global environmental problem. In the second half of the 20th century, many municipalities in Serbia experienced significant changes in land use, vegetation, and environmental conditions. The drive towards industrialization and urbanization aimed to improve the living standards of the population, but as a consequence, it led to substantial depopulation of rural areas and the adoption of inadequate agricultural practices, which, in turn, further intensified soil erosion. This study focuses on the Sokobanjska Moravica River basin (Eastern Serbia), extending to the Bovan Lake Dam and upstream, with a total area of 540.4 km². The basin is situated in a characteristic karst landscape. Changes in erosion intensity and runoff from this basin are analyzed using the Intensity of Erosion and Outflow (IntErO) model, which algorithmically integrates the widely used Erosion Potential Method (EPM) with innovative computational techniques to predict sediment production and runoff from the river basin accurately. This analysis utilizes GIS software and official statistical yearbook data, focusing on the period from the second half of the 20th century, including the analysis of the current state. According to our research, the most intensive changes in land use occurred between 1961 and 1971, marking the beginning of the period of a decline in rural population and, consequently, a decrease in erosion intensity. Key findings indicate that predominant changes in land use and vegetation led to a shift from crop farming to animal husbandry. After 1971, ongoing depopulation, particularly in rural areas, resulted in a gradual and steady decrease in erosion intensity. The primary aim of this study is to support policymakers in developing more effective soil and water conservation regulations. By making recommendations for the protection of vegetation, and thus the soil within this river basin, this research helps ensure their long-term preservation. Future research should focus on the long-term impacts of current land use practices and develop strategies to mitigate erosion in the context of changing climate conditions.

Adaptive potential in the face of a transmissible cancer in Tasmanian devils.

Emerging infectious diseases (EIDs) not only cause catastrophic declines in wildlife populations but also generate selective pressures that may result in rapid evolutionary responses. One such EID is devil facial tumour disease (DFTD) in the Tasmanian devil. DFTD is almost always fatal and has reduced the average lifespan of individuals by around 2 years, likely causing strong selection for traits that reduce susceptibility to the disease, but population decline has also left Tasmanian devils vulnerable to inbreeding depression. We analysed 22 years of data from an ongoing study of a population of Tasmanian devils on Freycinet Peninsula, Tasmania, to (1) identify whether DFTD may be causing selection on body size, by estimating phenotypic and genetic correlations between DFTD and size traits, (2) estimate the additive genetic variance of susceptibility to DFTD, and (3) investigate whether size traits or susceptibility to DFTD were under inbreeding depression. We found a positive phenotypic relationship between head width and susceptibility to DFTD, but this was not underpinned by a genetic correlation. Conversely, we found a negative phenotypic relationship between body weight and susceptibility to DFTD, and there was evidence for a negative genetic correlation between susceptibility to DFTD and body weight. There was additive genetic variance in susceptibility to DFTD, head width and body weight, but there was no evidence for inbreeding depression in any of these traits. These results suggest that Tasmanian devils have the potential to respond adaptively to DFTD, although the realised evolutionary response will critically further depend on the evolution of DFTD itself.

Decomposition of official population projections in Brazil

Brazil’s population has continually changed over time. However, the effects of each demographic component on official population projections are still unclear. In this research, we replicate the Population Projections Revision 2018 of the Brazilian Institute of Geography and Statistics using a projection matrix model and the cohort-component method by sex, age and geographic regions. Thereafter, we established four alternative scenarios to decompose the official benchmark scenario into four demographic effects (fertility, age structure, mortality, and migration) and one residual effect. The results reveal that fertility and age structure effects have been the main drivers of the population dynamics between 2010 and 2060. On the one hand, the negative effect of fertility below replacement level has been mostly offset by the still positive effect of the age structure, even across regions in the country. On the other hand, age structure effect has been decreasing over time. By 2048, the effects of age structure, mortality and migration will no longer counterbalance fertility effects, resulting in a population decline.