Lärkfalken – långdistansflyttare med okänd flyttväg

Abstract is not availabl

Svenska kärrhökar bland afrikanska juveler

Abstract is not availabl

Nigerflodens inlandsdelta – viktigt, men hotat övervintringsområde

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Resource tracking within and across continents in long-distance bird migrants

Migratory birds track seasonal resources across and between continents. We propose a general strategy of tracking the broad seasonal abundance of resources throughout the annual cycle in the longest-distance migrating land birds as an alternative to tracking a certain climatic niche or shorter-term resource surplus occurring, for example, during spring foliation. Whether and how this is possible for complex annual spatiotemporal schedules is not known. New tracking technology enables unprecedented spatial and temporal mapping of long-distance movement of birds. We show that three Palearctic-African species track vegetation greenness throughout their annual cycle, adjusting the timing and direction of migratory movements with seasonal changes in resource availability over Europe and Africa. Common cuckoos maximize the vegetation greenness, whereas red-backed shrikes and thrush nightingales track seasonal surplus in greenness. Our results demonstrate that the longest-distance migrants move between consecutive staging areas even within the wintering region in Africa to match seasonal variation in regional climate. End-of-century climate projections indicate that optimizing greenness would be possible but that vegetation surplus might be more difficult to track in the future

Remarkably similar migration patterns between different red-backed shrike populations suggest that migration rather than breeding area phenology determines the annual cycle

The regular fluctuation of resources across the Globe guides movements of migratory animals. To ensure sufficient reproductive output and maintain viable population sizes, migratory animals should match arrival at breeding areas with local peaks in resource availability. It is generally assumed that breeding phenology dictates the timing of the annual cycle, but this is poorly studied. Here, we use light-level geolocator tracking data to compare the annual spatiotemporal migration patterns of a long-distance migratory songbird, the red-backed shrike, Lanius collurio, breeding at widely different latitudes within Europe. We find that populations use remarkably similar migration routes and are highly synchronized in time. Additional tracks from populations breeding at the edges of the European range support these similar migration patterns. When comparing timing of breeding and vegetation phenology, as a measure of resource availability across populations, we find that arrival and timing of breeding corresponds to the peak in vegetation greenness at northern latitudes. At lower latitudes birds arrive simultaneously with the more northerly breeding populations, but after the local greenness peak, suggesting that breeding area phenology does not determine the migratory schedule. Rather, timing of migration in red-backed shrikes may be constrained by events in other parts of the annual cycle.</p

Interspecific Comparison of the Performance of Soaring Migrants in Relation to Morphology, Meteorological Conditions and Migration Strategies

Peer reviewe

First-Time Migration in Juvenile Common Cuckoos Documented by Satellite Tracking

Being an obligate parasite, juvenile common cuckoos Cuculus canorus are thought to reachtheir African wintering grounds from Palearctic breeding grounds without guidance fromexperienced conspecifics but this has not been documented. We used satellite tracking tostudy naïve migrating common cuckoos. Juvenile cuckoos left breeding sites in Finlandmoving slowly and less consistently directed than adult cuckoos. Migration of the juveniles(N = 5) was initiated later than adults (N = 20), was directed toward the southwest±significantlydifferent from the initial southeast direction of adults±and included strikingly long BalticSea crossings (N = 3). After initial migration of juvenile cuckoos toward Poland, themigration direction changed and proceeded due south, directly toward the winter grounds,as revealed by a single tag transmitting until arrival in Northwest Angola where northernadult cuckoos regularly winter. Compared to adults, the juvenile travelled straighter andfaster, potentially correcting for wind drift along the route. That both migration route and timingdiffered from adults indicates that juvenile cuckoos are able to reach proper winteringgrounds independently, guided only by their innate migration programme.</p

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Migration strategies of raptors – spatio-temporal adaptations and constraints in travelling and foraging

My dissertation is about bird migration and addresses questions about how raptors adapt to the fluctuating environments during the transition seasons between breeding and wintering. The migration is highly affected by local prey abundance, foraging strategies, weather conditions and landscape patterns along the migration routes as well as navigation and orientation mechanisms and cues. Interesting findings in my studies were how raptors can mix foraging and active migration during their travels. A strategy of fly-and-forage migration is favourable for birds that hunt on their wings, able to combine foraging with covering travel distance. Fly-and-forage migration is favourable for Ospreys in Europe because benefits (energy intake) more than outweigh costs (reduced flight time). Among different species and populations of migratory raptors, duration of migration increased approximately in proportion to the square root of total migration distance. This reflects a shifting balance in the selection for speed and duration depending on distance of migration. The general wind patterns along the migration routes with dominating winds from the east over the Saharan Desert and from the west over Europe, mediate migration in a clockwise loop, where Marsh Harriers could increase flight speed across the desert with tailwinds in autumn and by avoiding headwinds in spring. In addition to seas and deserts, we found the equatorial rain forest as a potential ecological barrier for migrating birds. A striking relationship of route convergence with the distribution of continuous rain forest suggests minimized crossings of this habitat by Hobbies. The migration journeys by raptors across the Sahara Desert showed that 37% of all crossings included events of aberrant behaviour indicating difficulties or hazards. Mortality associated with the Sahara passages contributed to about half of the total annual mortality among juveniles as well as adults, demonstrating that this passage has a profound influence on survival and fitness of the migrants. Comparisons of satellite tracking and ring recoveries of raptors revealed agreement in the geographical distribution but differences in timing of migration. Tracks showed a faster progress for long-distance migrants, which probably related to more detailed information from tracking in Africa, difficulties in judging time of death for recovered birds and an overrepresentation of recoveries in Europe. An important and challenging goal for future studies of raptor migration will be to track juveniles from their first journeys until they are migrating as experienced adults. This would give a better understanding of how migration strategies are developed and to what degree they are inherited or based on learning

Sträckobservationer vid Hammarsjön 2002 och 2003

Abstract is not availabl