RESUMO
Effective conservation planning for species of concern requires long-term monitoring data that can accurately estimate population trends. Supplemental or alternative methods for estimating population trends are necessary for species that are poorly sampled by traditional breeding bird survey methods. Counts of migrating birds are commonly used to assess raptor population trends and could be useful for additional taxa that migrate diurnally and are difficult to monitor during the breeding season. In North America, the Common Nighthawk (Chordeiles minor) is challenging to detect during comprehensive dawn surveys like the North American Breeding Bird Survey and is considered a species of conservation concern because of steep population declines across its range. We conducted standardized evening counts of migrating Common Nighthawks at a fixed survey location along western Lake Superior each autumn from 2008 to 2022. To document peak migration activity, counts spanned ~3 hours each evening from mid-August to early September for a mean of 19.4 ± 2.4 days. These count data were then used to assess the effects of weather on daily counts and high-count days and to calculate population trends over this 15-year period. We used generalized linear mixed effects models to determine the relationship between daily counts and high-count days (i.e., ≥1000 migrating nighthawks) and weather variables. Additionally, using our 15-year dataset, we calculated a geometric mean passage rate that accounted for annual differences in weather to estimate count trends. Annual counts averaged ~18,000 (min = 2514, max = 32,837) individuals and high-count days occurred 56 times throughout the course of the study. Model results indicated lighter, westerly winds and warmer temperatures were associated with higher daily counts and greater probability of a large migratory flight. Results from the trend analyses suggest stable or non-significantly increasing trends for Common Nighthawks during this monitoring period; however, the trend models explained a relatively low percentage of the variation in the counts. Results from a power analysis suggest that continued monitoring efforts and adjustments with weather covariates will be necessary to effectively use visible migration count data to estimate Common Nighthawk trends. Establishing annual monitoring programs that use standardized visual counts to document Common Nighthawk migration at key sites across North America may provide supplemental information useful for population trend estimates of this species. Therefore, we advocate for the use of visible migration counts to monitor Common Nighthawks in North America and emphasize the value of long-term monitoring efforts.
Des données de suivi à long terme permettant de calculer avec précision les tendances démographiques sont garantes d'une planification réussie de la conservation d'espèces préoccupantes. Des méthodes complémentaires ou alternatives d'estimation des tendances démographiques sont nécessaires dans le cas d'espèces mal échantillonnées par les méthodes traditionnelles de relevé d'oiseaux nicheurs. Le dénombrement d'oiseaux migrateurs est couramment utilisé pour évaluer la tendance des populations de rapaces et pourrait servir pour d'autres taxons qui migrent de jour et sont difficiles à suivre pendant la saison de nidification. En Amérique du Nord, l'Engoulevent d'Amérique (Chordeiles minor) est difficile à détecter au cours de relevés généraux réalisés à l'aube, tel le Relevé des oiseaux nicheurs d'Amérique du Nord (BBS), et est considéré comme une espèce dont la conservation est préoccupante en raison de la baisse marquée de ses effectifs dans toute son aire de répartition. Nous avons effectué des comptages en soirée standardisés d'engoulevents en migration à un site fixe localisé du côté ouest du lac Supérieur, chaque automne de 2008 à 2022. Afin de caractériser le pic d'activité migratoire, les comptages ont duré ~3 heures chaque soir de la mi-août au début de septembre, durant 19,4 ± 2,4 jours en moyenne. Ces données ont ensuite servi pour évaluer l'effet des conditions météorologiques sur les comptages quotidiens et les jours d'activité migratoire élevée et calculer la tendance démographique au cours de ces 15 ans. Nous avons utilisé des modèles linéaires généralisés à effets mixtes pour déterminer la relation entre les comptages quotidiens et les jours d'activité migratoire élevée (c.-à-d. ≥1000 engoulevents) et les variables météorologiques. En outre, en utilisant notre jeu de données sur 15 ans, nous avons calculé la moyenne géométrique du taux de passage tenant compte des différences météorologiques annuelles afin d'estimer la tendance des comptages. La moyenne des comptages annuels était de ~18 000 (min = 2514, max = 32 837) individus et nous avons observé 56 cas d'activité migratoire élevée au cours de l'étude. Les résultats du modèle ont indiqué que des vents plus légers et de l'ouest, et des températures plus chaudes étaient associés à des comptages quotidiens plus élevés et à une plus grande probabilité d'une activité migratoire importante. Les résultats de l'analyse des tendances indiquent que les engoulevents ont montré une tendance stable ou en augmentation non significative au cours de cette période de suivi; cependant, les modèles de tendances n'ont expliqué qu'un pourcentage relativement faible de la variation des comptages. Les résultats d'une analyse de puissance révèlent que des suivis réguliers et des ajustements avec des covariables météorologiques seront nécessaires pour utiliser efficacement les données de comptages visuels réalisés en migration afin d'estimer la tendance de l'Engoulevent d'Amérique. La mise en place d'un programme de suivis annuels fondés sur des comptages visuels standardisés destiné à caractériser la migration de l'Engoulevent d'Amérique sur des sites clés en Amérique du Nord pourrait fournir des informations supplémentaires utiles pour estimer les tendances démographiques de cette espèce. Par conséquent, nous préconisons l'utilisation de comptages visuels en migration pour suivre l'Engoulevent d'Amérique en Amérique du Nord et soulignons la valeur de suivis à long terme.
RESUMO
Grassy ecosystems cover more than 40% of the world's terrestrial surface, supporting crucial ecosystem services and unique biodiversity. These ecosystems have experienced major losses from conversion to agriculture with the remaining fragments threatened by global change. Woody plant encroachment, the increase in woody cover threatening grassy ecosystems, is a major global change symptom, shifting the composition, structure, and function of plant communities with concomitant effects on all biodiversity. To identify generalisable impacts of encroachment on biodiversity, we urgently need broad-scale studies on how species respond to woody cover change. Here, we make use of bird atlas, woody cover change data (between 2007 and 2016) and species traits, to assess: (1) population trends and woody cover responses using dynamic occupancy models; (2) how outcomes relate to habitat, diet and nesting traits; and (3) predictions of future occupancy trends, for 191 abundant, southern African bird species. We found that: (1) 63% (121) of species showed a decline in occupancy, with 18% (34) of species' declines correlated with increasing woody cover (i.e. losers). Only 2% (4) of species showed increasing population trends linked with increased woody cover (i.e. winners); (2) Open habitat specialist, invertivorous, ground nesting birds were the most frequent losers, however, we found no definitive evidence that the selected traits could predict outcomes; and (3) We predict open habitat loser species will take on average 52 years to experience 50% population declines with current rates of encroachment. Our results bring attention to concerning region-wide declining bird population trends and highlight woody plant encroachment as an important driver of bird population dynamics. Importantly, these findings should encourage improved management and restoration of our remaining grassy ecosystems. Furthermore, our findings show the importance of lands beyond protected areas for biodiversity, and the urgent need to mitigate the impacts of woody plant encroachment on bird biodiversity.
Assuntos
Biodiversidade , Aves , Ecossistema , Dinâmica Populacional , Animais , Aves/fisiologia , Conservação dos Recursos Naturais , África do SulRESUMO
Ongoing internal dialog on the limitations of Euro-American developmental science has opened up space to explore how best to work toward a knowledge base that is adequately representative of the values, cultures, epistemic traditions, and lived experiences of peoples, nations, and regions around the world. So far, recommendations for the advancement of a global developmental science have focused preponderantly on (1) methodological considerations and (2) an architecture to support cross-disciplinary international collaborative inquiry and/or enhance research capacity building for Majority World scholars and institutions. In this commentary, instead of focusing on specific contributions to the Special Issue, I make a case for an explicit commitment to field-building within Majority World contexts as the primary gap-closing path toward the cultivation of a global developmental science knowledge base. I begin with a worldwide population analysis to demonstrate the magnitude of geopolitical, eco-cultural, and epistemic imbalances inherent in the shaping of Euro-American developmental science. In tandem with the Special Issue's central theme, I draw on scholarship from the fields of history, sociology, and political economy to link decolonial theory to the advancement of a global developmental science. Finally, I explore ways in which exemplary research establishments already engaged in prolific inquiry and research training may be ideal candidates to support field-building and help to advance multidisciplinary inquiry within an ethos of epistemic and methodological pluralism.
Assuntos
Desenvolvimento do Adolescente , Diversidade Cultural , Humanos , Adolescente , Bases de Conhecimento , InternacionalidadeRESUMO
INTRODUCTION: to investigate the childhood epilepsy incidence, population trends, associated factors, and validate the national population registers. METHODS: a comprehensive comparative analysis of childhood epilepsy in the population during two distinct time intervals using medical records, appropriate national medical and population registers, and two random samples for control. RESULTS: In 1961-1964, the average incidence of epilepsy was 38/100,000 and during 1991-2000 65.9 (95 % CI 59.6 to 72.2) and 65.6/100,000 person-years after adjustment for the European Standard Population. This increase was significant (p<0.0001) as was a decline (p<0.003) from 1991 to 1995 to 1996-2000. The decline in incidence for girls occurred at a younger age compared to boys. Epilepsy cases associated with prenatal and perinatal factors were 50 % lower in 1991-2000 than in 1961-1964, especially related to asphyxia, infections, pre-eclampsia, and imminent abortion. The national Register for Healthcare independently identified 94.5 % of relevant cases (University Hospital alone 81.2 %, and Drug Register alone 74.3 %). DISCUSSION: Over the past five decades, the incidence rate of childhood epilepsy has exhibited a dynamic pattern, with a notable increase until the 1990's, followed by a stabilization at an incidence rate of approximately 60-70 per 100,000 person-years. Our findings, in line with other recent Finnish research, support a significant decrease in incidence since the mid-1990's. The underlying reasons for the increase and decrease remain unclear. Finnish national registers for epilepsy have established themselves as highly dependable resources for conducting epidemiological research. CONCLUSION: Childhood epilepsy incidence in Finland is similar to other industrialized countries, but there are signs of a declining trend emerging.
Assuntos
Epilepsia , Sistema de Registros , Humanos , Finlândia/epidemiologia , Incidência , Feminino , Masculino , Epilepsia/epidemiologia , Criança , Pré-Escolar , Lactente , Adolescente , Sistema de Registros/estatística & dados numéricos , Recém-NascidoRESUMO
The ongoing depletion of natural systems and associated biodiversity decline is of growing international concern. Climate change is expected to exacerbate anthropogenic impacts on wild populations. The scale of impact on ecosystems and ecosystem services will be determined by the impact on a multitude of species and functional groups, which due to their biology and numbers are difficult to monitor. The IPCC has argued that surveillance or monitoring is critical and proposed that monitoring systems should be developed, which not only track developments but also function as "early warning systems." Human populations are already generating large continuous datasets on multiple taxonomic groups through internet searches. These time series could in principle add substantially to current monitoring if they reflect true changes in the natural world. We here examined whether information on internet search frequencies delivered by the Danish population and captured by Google Trends (GT) appropriately informs on population trends in 106 common Danish bird species. We compared the internet search activity with independent equivalent population trend assessments from the Danish Ornithological Society (BirdLife Denmark/DOF). We find a fair concordance between the GT trends and the assessments by DOF. A substantial agreement can be obtained by omitting species without clear temporal trends. Our findings suggest that population trend proxies from internet search frequencies can be used to supplement existing wildlife population monitoring and to ask questions about an array of ecological phenomena, which potentially can be integrated into an early warning system for biodiversity under climate change.
Assuntos
Ecossistema , Ferramenta de Busca , Animais , Humanos , Big Data , Monitoramento Ambiental , Aves , DinamarcaRESUMO
Single phenological measures, like the average rate of phenological advancement, may be insufficient to explain how climate change is driving trends in animal populations. Here, we develop a multifactorial concept of spring phenology-including the onset of spring, spring duration, interannual variability, and their temporal changes-as a driver for population dynamics of migratory terrestrial species in seasonal environments. Using this conceptual model, we found that effects of advancing spring phenology on animal populations may be buffered or amplified depending on the duration and interannual variability of spring green-up, and those effects are modified by evolutionary and plastic adaptations of species. Furthermore, we compared our modelling results with empirical data on normalized difference vegetation index-based spring green-up phenology and population trends of 106 European landbird finding similar associations. We conclude how phenological changes are expected to affect migratory bird populations across Europe and identify regions that are particularly prone to suffer population declines.
Assuntos
Migração Animal , Mudança Climática , Animais , Estações do Ano , Europa (Continente) , Aves , TemperaturaRESUMO
Understanding how different organisms cope with changing temperatures is vital for predicting future species' distributions and highlighting those at risk from climate change. As ectotherms, butterflies are sensitive to temperature changes, but the factors affecting butterfly thermoregulation are not fully understood. We investigated which factors influence thermoregulatory ability in a subset of the Mediterranean butterfly community. We measured adult thoracic temperature and environmental temperature (787 butterflies; 23 species) and compared buffering ability (defined as the ability to maintain a consistent body temperature across a range of air temperatures) and buffering mechanisms to previously published results from Great Britain. Finally, we tested whether thermoregulatory ability could explain species' demographic trends in Catalonia. The sampled sites in each region differ climatically, with higher temperatures and solar radiation but lower wind speeds in the Catalan sites. Both butterfly communities show nonlinear responses to temperature, suggesting a change in behaviour from heat-seeking to heat avoidance at approximately 22°C. However, the communities differ in the use of buffering mechanisms, with British populations depending more on microclimates for thermoregulation compared to Catalan populations. Contrary to the results from British populations, we did not find a relationship between region-wide demographic trends and butterfly thermoregulation, which may be due to the interplay between thermoregulation and the habitat changes occurring in each region. Thus, although Catalan butterfly populations seem to be able to thermoregulate successfully at present, evidence of heat avoidance suggests this situation may change in the future.
Assuntos
Borboletas , Animais , Borboletas/fisiologia , Regulação da Temperatura Corporal , Temperatura , Temperatura Alta , Ecossistema , Mudança ClimáticaRESUMO
The little bustard (Tetrax tetrax) is a steppe bird strongly and negatively influenced by agricultural intensification in Europe. Here, we use the little bustard as a model species to examine how favourability (relative occurrence likelihood of a species based on environmental characteristics, such as habitat availability) varies regionally with degree of protection in north-western Spain. The Natura2000 network is one of the main biodiversity conservation tools of the European Union, aiming to protect areas hosting species of conservation concern from unfavourable land-use changes. The network covers many landscapes across the continent, including farmland. Additionally, we examine the relationship between trends in land-use favourability and little bustard population trends over a decade in the Nature Reserve of Lagunas de Villafáfila, a protected area also in the Natura2000 network where active and intense management focused on steppe bird conservation is carried out. Favourability was much greater in Villafáfila than in both protected areas with lower degree of protection and in non-protected areas. Land-use favourability increased slightly between 2011 and 2020 both in and out of protected areas, whereas little bustard populations declined sharply in that period, even in Villafáfila. Spatial variations in little bustard abundance within Villafáfila depended on social attraction (increasing with the number of neighbouring males) but not significantly on small-scale variations in land-use favourability. These results suggest that land-use management in Natura2000 areas needs to be more conservation-focused, favouring natural and seminatural habitats and traditional farming practices to improve land-use favourability for little bustards and other steppe birds. Additional factors, such as field-level agricultural management or social interaction variables that may cause an Allee effect, should be incorporated in little bustard favourability models to improve their use in conservation planning.
Assuntos
Agricultura , Biodiversidade , Masculino , Animais , Aves , Europa (Continente) , União EuropeiaRESUMO
OBJECTIVES: Risk of death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has fallen during the pandemic, largely due to immunity from vaccination. In England, the timing and extent of this reduction varied due to staggered eligibility during the primary vaccination campaign, based on age and clinical risk group. Duration of protection is less well understood. Our objective was to estimate the case fatality risk (CFR) by vaccination status and time since last dose during a period of widespread community testing, to better understand the impact of coronavirus disease 2019 (COVID-19) vaccination and duration of protection. DESIGN: SARS-CoV-2 cases diagnosed between May 2020 and February 2022 were linked to vaccine records from the National Immunisation Management System. CFR was calculated as the proportion of cases that died of COVID-19 per the death certificate, aggregated by week of specimen and stratified by 10-year age band and vaccination status. SETTING: England, UK. PARTICIPANTS: A total of 10,616,148 SARS-CoV-2 cases, aged ≥18 years, recorded by England's laboratory reporting system. MAIN OUTCOME MEASURES: Case fatality risk of COVID-19, stratified by age band and vaccination status. RESULTS: Overall, a reduction in CFR was observed for all age bands, with a clear temporal link to when the age group became eligible for primary vaccination and then the first booster. CFR increased with age (0.3% 50-59 years; 1.2% 60-69; 4.7% 70-79; 16.3% 80+) and was highest in the unvaccinated - albeit a reduction was observed over time. The highest CFR was seen in the unvaccinated 80+ group prior to vaccination rollout (30.6%). CFR was consistently lowest in vaccinated populations within 6 months of last dose, yet increased after over 6 months elapsed since last dose, across all age bands. CONCLUSIONS: COVID-19 CFR reduced after vaccination, with the lowest CFR seen across all age bands when vaccinated up to 6 months prior to specimen date. This provides some evidence for continued booster doses in older age groups.
Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/mortalidade , COVID-19/prevenção & controle , COVID-19/epidemiologia , Inglaterra/epidemiologia , Adulto , Pessoa de Meia-Idade , Vacinas contra COVID-19/administração & dosagem , Idoso , Masculino , Adulto Jovem , Adolescente , Feminino , Vacinação/estatística & dados numéricos , Idoso de 80 Anos ou mais , Fatores de TempoRESUMO
Reproductive activity of Chelonia mydas (Testudines: Cheloniidae) in Isla de Aves, Venezuela (2001-2008). The second major nesting-site for green turtles in the Caribbean is Isla de Aves, an island protected as a wildlife refuge since 1972, located at 650km Northeast from La Guaira, Venezuela. In this island, the nesting population monitoring started in 1972 and in a more continuous way after 1978, when a Scientific-Naval Station was established and scientific observations started. Since historical data show that female captures had severely affected population levels in this island before 1978, this study aim to describe recent reproductive activities. For this, during the nesting seasons of 2001-2002 and 2005-2008, nesting females were measured and tagged using metal flipper tags. A total of 458 nights were sampled observing 5 154 female emergences, with a maximum of 53 in a single night. Non-observed emergences were calculated fitting the temporal distribution of observed emergences to a normal curve. Total emergences estimated varied from =637.1±106.6 in 2001 to =2 853±42.5 in 2008 (ANOVA F(6.5df)=60.37, p<0.0001). Internesting interval in the same season was estimated in =10.71±1.32 days. Clutch frequency in a nesting season was calculated as =1.71±1.6 times per female and season. Estimated number of nesting females per year varied from =373±12.5 females in 2001 to =1 669±56.1 females in 2008 (ANOVA F (5.6df)=89.42, p<0.0001); with a positive and significant trend (r=0.842, p=0.036). Results show that nesting females numbers are increasing. We suggest that the protection of the nesting area for more than 30 years, has contributed with this population increase. Rev. Biol. Trp. 60 (2): 745-758. Epub 2012 June 01.
Isla de Aves, una isla a 650km de La Guaira, Venezuela, protegida como Refugio de Fauna Silvestre, constituye el segundo sitio de mayor anidación de la tortuga verde (Chelonia mydas) (Linnaeus 1758) en el Caribe. El seguimiento de la población comenzó en 1972 y de manera más continua desde 1978. Los datos históricos indican que la captura de hembras en la isla, afectó severamente la población hasta 1978, cuando fue construida una base científico-naval. Durante las temporadas de anidación entre 2001-2008 con excepción de 2003 y 2004, las hembras fueron marcadas con placas metálicas y medidas. Asimismo, se muestreó durante 458 noches, en donde se observaron 5 154 eventos, con un máximo de 53 por noche. Los posibles eventos no observados fueron calculados ajustando la distribución temporal de eventos observados a una curva normal. El total de eventos estimados varió de =637.1±106.6 en 2001 a =2 853±42.5 en 2008 (ANOVA F(6.5gl)=60.37, p<0.0001). El intervalo entre reanidaciones fue de =10.7±1.32 días. La frecuencia de anidación se calculó en =1.71±1.6 veces por hembra. El número de hembras estimadas varió entre =373±12.5 para 2001 y =1 669±56.1 para 2008 (ANOVA F(5.6gl)=89.42, p<0.0001). La tendencia es significativa (r=0.842, p=0.036). Los resultados indican que el número de hembras que anidan en Isla de Aves ha aumentado, y se sugiere que más de 30 años de protección del área de reproducción está resultando en un creciente número de hembras.