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

International Bird Conservation Conference in Hungary

The regular (7th) International Bird Conservation Conference, organized by the Hungarian national network company MAVIR, in collaboration with the Society for the protection of birds in Hungary (MME/Birdlife) and the Hermann Otto Institute, took place in Hungary on November 7–8, 2016. At this time the conference was focused on two important areas – the impact of power lines on bird populations and the problems of illegal poisoning, both birds and other animals

Защита гнездового участка ястребиной совы от негативного влияния воздушных линий электропередачи 6–10 кВ в Нижегородской области, Россия

Рассматриваются последствия негативного влияния воздушных линий (ВЛ) электропередачи 6–10 кВ на успешность размножения редкого и охраняемого в Нижегородской области вида ночных хищных птиц – ястребиной совы (Surnia ullula). Во время гнездования отмечена гибель в результате поражения электрическим током ВЛ одной из взрослых птиц, и предполагается гибель по этой же причине одного из слётков. Обсуждается адекватность действий контролирующих органов и хозяйствующих субъектов – владельцев птицеопасных линий электропередачи

Modern Status of the Steppe Eagle Population in Kalmykia, Russia

The article presents the results of the Steppe Eagle (Aquila nipalensis) monitoring in the Republic of Kalmykia in 2013–2015. For 2011–2015 the population of Steppe Eagle in Kalmykia decreased by 23% and is 404–720, at average 527 breeding pairs. In 2015 the average density of occupied breeding territories on the main part of the Steppe Eagle breeding ground in Kalmykia was about 1.7 per 100 km2, in the breeding ground of the high density of species, on Ergeninskaya hill, where about 20% of Kalmyk Steppe Eagle population is nesting – 7,9/100 km2. In 2015 the density of successful pairs was1.3 (0.98–1.7) pairs/100 km2 on the main areas, on Ergeninskaya hill – 7.1 (4.9 – 10.4) pairs/100 km2, observed breeding success in 2015 is 1.58±1.11 nestlings per occupied breeding territory. The rejuvenation of the population has been noted: among the birds on the breeding territories the proportion of partners younger than 5 years has increased by 3 times in 2 years – from 1.75 to 5.26%. The main threats to the Steppe Eagle in the Republic of Kalmykia are death on power lines, steppe fires, destruction of nests by cattle or killing of nestlings by herding dogs, disturbance factor in grazing. It is likely that the decline of eagles’ population is due to increasing of negative factors on the migration routes and wintering grounds

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

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

Pedersen L, Onrubia A, Vardanis Y, Barboutis C, Waasdorp S, van Helvert M, Geertsma M, Ekberg P, Willemoes M, Strandberg R, Matsyna E, Matsyna A, Klaassen RHG, Alerstam T, Thorup K, Tøttrup AP. 2020. Remarkably similar migration patterns between different red-backed shrike populations suggest that migration rather than breeding area phenology determines the annual cycle. J Avian Biol. doi:10.1111/jav.02475,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.

Migration of red-backed shrike populations (data from Pedersen et al. 2020)-twilights

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