29 research outputs found
Rare case of an adult male Montagu's Harrier Circus pygargus over-summering in West Africa, as revealed by GPS tracking
Over-summering within or near the African wintering range by immature, non-breeding individuals occurs regularly in several species of long-distance migratory raptors, yet the extent of over-summering in Africa by adult birds remains unclear. In this study, we describe a case of an adult Montagu's Harrier over-summering in Africa, as revealed by GPS tracking. By relating detailed knowledge of the bird's movements to remotely sensed environmental data (normalized difference vegetation index, NDVI), we show that over-summering in this case was likely related to an exceptionally difficult breeding season the previous year rather than an effect of adverse weather conditions encountered during the winter or a failed attempt to migrate. Various factors are discussed as potential driving forces behind the bird's intra-African movements. Finally, we relate the documented case to a large number of North European Montagu's Harriers studied by telemetry and show that over-summering in Africa by adult individuals is indeed a rare event
Cross-taxa generalities in the relationship between population abundance and ambient temperatures
Longâterm declines of European insectivorous bird populations and potential causes
Evidence of declines in insect populations has recently received considerable scientific and societal attention. However, the lack of longâterm insect monitoring makes it difficult to assess whether declines are geographically widespread. By contrast, bird populations are well monitored and often used as indicators of environmental change. We compared the population trends of European insectivorous birds with those of other birds to assess whether patterns in bird population trends were consistent with declines of insects. We further examined whether declines were evident for insectivores with different habitats, foraging strata, and other ecological preferences. Bird population trends were estimated for Europe (1990â2015) and Denmark (1990â2016). On average, insectivores declined over the study period (13% across Europe and 28% in Denmark), whereas omnivores had stable populations. Seedeaters also declined (28% across Europe; 34% in Denmark), but this assessment was based on fewer species than for other groups. The effects of insectivory were stronger for farmland species (especially grassland species), for ground feeders, and for coldâadapted species. Insectivory was associated with longâdistance migration, which was also linked to population declines. However, many insectivores had stable populations, especially habitat generalists. Our findings suggest that the decline of insectivores is primarily associated with agricultural intensification and loss of grassland habitat. The loss of both seed and insect specialists indicates an overall trend toward bird communities dominated by diet generalists
Schlaich_etal_2017_BiolLetters_gps_tracking_data_20170410
This file contains the GPS-tracking data of Montaguâs Harriers used for analyses on daily and total flight distances and contains the following columns: season (name of the bird, years), population (France, Netherlands, Denmark), sex, date_time (date and time in UTC), ann.rough (annotation of annual cycle phases: breeding, autumn migration, winter, spring migration), latitude, longitude, speed_2d (instantaneous speed measured by the GPS-device)
Data from: A circannual perspective on daily and total flight distances in a long-distance migratory raptor, the Montagu's harrier, Circus pygargus
Long-distance migrants are particularly recognized for the distances covered on migration, yet little is known about the distances they cover during the rest of the year. GPS-tracks of 29 Montagu's harriers from breeding areas in France, The Netherlands and Denmark showed that harriers fly between 35 653 and 88 049 km yrâ1, of which on average only 28.5% is on migration. Mean daily distances during migration were 296 km dâ1 in autumn and 252 km dâ1 in spring. Surprisingly, males' daily distances during breeding (217 km dâ1) were close to those during migration, whereas breeding females moved significantly less (101 km dâ1) than males. In terms of flight distance, the breeding season seemed nearly as demanding as migration periods for males. During the six winter months, both sexes moved less (114 and 128 km dâ1 for females and males, respectively) than during migration. Harriers therefore covered shorter daily distances during winter which might allow birds to compensate for the more demanding phases of migration and breeding
EGMP Population Status and Assessment Report
This report provides the 2021 information for the goose populations managed under the EGMP. The information cover aspects related to population status, survival, productivity, hunting bags and derogation statistics, progress in population models, as well as assessment of cumulative impact of derogation and legal hunting and, for some populations, management recommendations. These may differ for each species, as available data differs from species to species (or populations identified in the framework of the EGMP). Status of indicators related to other aspect of the management plans, such as socioeconomic issues and ecosystem services provided by geese, are presented in the Adaptive Framework Management Programmes (AFMPs) under Indicator factsheets
A circannual perspective on daily and total flight distances in a long-distance migratory raptor, the Montagu's harrier, <i>Circus pygargus</i>
Long-distance migrants are particularly recognized for the distances covered on migration, yet little is known about the distances they cover during the rest of the year. GPS-tracks of 29 Montagu's harriers from breeding areas in France, The Netherlands and Denmark showed that harriers fly between 35 653 and 88 049 km yrâ1, of which on average only 28.5% is on migration. Mean daily distances during migration were 296 km dâ1 in autumn and 252 km dâ1 in spring. Surprisingly, males' daily distances during breeding (217 km dâ1) were close to those during migration, whereas breeding females moved significantly less (101 km dâ1) than males. In terms of flight distance, the breeding season seemed nearly as demanding as migration periods for males. During the six winter months, both sexes moved less (114 and 128 km dâ1 for females and males, respectively) than during migration. Harriers therefore covered shorter daily distances during winter which might allow birds to compensate for the more demanding phases of migration and breeding
Data from: A circannual perspective on daily and total flight distances in a long-distance migratory raptor, the Montagu's harrier, Circus pygargus
Long-distance migrants are particularly recognized for the distances covered on migration, yet little is known about the distances they cover during the rest of the year. GPS-tracks of 29 Montagu's harriers from breeding areas in France, The Netherlands and Denmark showed that harriers fly between 35 653 and 88 049 km yrâ1, of which on average only 28.5% is on migration. Mean daily distances during migration were 296 km dâ1 in autumn and 252 km dâ1 in spring. Surprisingly, males' daily distances during breeding (217 km dâ1) were close to those during migration, whereas breeding females moved significantly less (101 km dâ1) than males. In terms of flight distance, the breeding season seemed nearly as demanding as migration periods for males. During the six winter months, both sexes moved less (114 and 128 km dâ1 for females and males, respectively) than during migration. Harriers therefore covered shorter daily distances during winter which might allow birds to compensate for the more demanding phases of migration and breeding. The data package contains two datasets: - Schlaich_etal_2017_BiolLetters_gps_tracking_data_20170410 This file contains the GPS-tracking data of Montaguâs Harriers used for analyses on daily and total flight distances and contains the following columns: season (name of the bird, years), population (France, Netherlands, Denmark), sex, date_time (date and time in UTC), ann.rough (annotation of annual cycle phases: breeding, autumn migration, winter, spring migration), latitude, longitude, speed_2d (instantaneous speed measured by the GPS-device). - Schlaich_etal_2017_BiolLetters_ high_resolution_data_20170410 This file contains the high resolution GPS-tracking data of Montaguâs Harriers used to calculate correction factors according to sampling interval and contains the following columns: season (name of the bird, years), date_time (date and time in UTC), ann.rough (annotation of annual cycle phases: breeding, autumn migration, winter, spring migration), latitude, longitude, speed_2d (instantaneous speed measured by the GPS-device)
Low morbidity in Danish patients with common variable immunodeficiency disorder infected with severe acute respiratory syndrome coronavirus 2
Manifestations and outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are not well documented in patients with common variable immunodeficiency disorder (CVID). A Danish nationwide retrospective clinician-reported survey. Eleven patients with CVID and SARS-CoV-2 infection were identified. The median age was 50 years (range 22â72). All were on immunoglobulin replacement therapy. Eight patients had other pre-existing co-morbidities. Three patients were asymptomatic during the SARS-CoV-2 infection while seven developed mild coronavirus disease 2019 (COVID-19). One patient had more severe disease with hypoxia and required oxygen therapy. This patient had multiple co-morbidities including well known risk factors for severe COVID-19. All patients recovered. The results suggest that CVID may not be a risk factor for severe COVID-19. However, further monitoring of this immunodeficient population is needed to confirm our observation.</p
Schlaich_etal_2017_BiolLetters_ high_resolution_data_20170410
This file contains the high resolution GPS-tracking data of Montaguâs Harriers used to calculate correction factors according to sampling interval and contains the following columns: season (name of the bird, years), date_time (date and time in UTC), ann.rough (annotation of annual cycle phases: breeding, autumn migration, winter, spring migration), latitude, longitude, speed_2d (instantaneous speed measured by the GPS-device)