Enhancing monitoring and transboundary collaboration for conserving migratory species under global change: The priority case of the red kite.

Calls for urgent action to conserve biodiversity under global change are increasing, and conservation of migratory species in this context poses special challenges. In the last two decades the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has provided a framework for several subsidiary instruments including action plans for migratory bird species, but the effectiveness and transferability of these plans remain unclear. Such laws and policies have been credited with positive outcomes for the conservation of migratory species, but the lack of international coordination and on-ground implementation pose major challenges. While research on migratory populations has received growing attention, considerably less emphasis has been given to integrating ecological information throughout the annual cycle for examining strategies to conserve migratory species at multiple scales in the face of global change. We fill this gap through a case study examining the ecological status and conservation of a migratory raptor and facultative scavenger, the red kite (Milvus milvus), whose current breeding range is limited to Europe and is associated with agricultural landscapes and restricted to the temperate zone. Based on our review, conservation actions have been successful at recovering red kite populations within certain regions. Populations however remain depleted along the southern-most edge of the geographic range where many migratory red kites from northern strongholds overwinter. This led us to a forward-looking and integrated strategy that emphasizes international coordination involving researchers and conservation practitioners to enhance the science-policy-action interface. We identify and explore key issues for conserving the red kite under global change, including enhancing conservation actions within and outside protected areas, recovering depleted populations, accounting for climate change, and transboundary coordination in adaptive conservation and management actions. The integrated conservation strategy is sufficiently general such that it can be adapted to inform conservation of other highly mobile species subject to global change.

How littered are birds' of prey nests? Study of two sympatric species.

Anthropogenic activity results in production of wastes, including litter in the environment. The problem of waste pollution is especially noticeable and usually discussed from the perspective of marine environments. It is significantly less addressed in terrestrial habitats, where the spatial dispersion of litter makes it difficult to assess the degree of pollution and its impact on the ecosystems. In this study, we present the problem of littering the terrestrial environments in the context of their inclusion in raptor nests, which are relatively rare elements of these ecosystems and because they comprise the top positions in their trophic chains, are exemplary bioindicators. During the breeding season we quantitatively and qualitatively assessed the anthropogenic debris present in the nests of 48 Back Kites (Milvus migrans) and Red kites (Milvus milvus). We found that the prevalence of litter in the nests was 100% for both species. The average number of litter items and average total area of litter recorded per nest was 31.3 and 0.44 m2, respectively and differed between species, where higher values were recorded for the Black Kite than for the Red Kite (53.1 vs. 23.8 and 0.54 m2 vs. 0.34 m2, respectively). Taking into account the average nest surface area of both studied species (0.33 m2 and 0.57 m2, respectively), obtained values indicate large littering of the studied nests. Furthermore, 71% of identified debris items were plastics which constituted 65% of the total surface of all recorded debris. Our study suggests a high availability of litter in the terrestrial habitats that constitute the breeding territories of the two sympatric study species.

High genetic diversity and low differentiation retained in the European fragmented and declining Greater Spotted Eagle (Clanga clanga) population.

Characterising genetic diversity and structure of populations is essential for effective conservation of threatened species. The Greater Spotted Eagle (Clanga clanga), a large and globally vulnerable raptor, is extinct or in severe decline in most of its previous range in Europe. We assessed whether the remnants of European population are genetically impoverished, and isolated from each other. We evaluated levels of genetic diversity and population structuring by sequencing mitochondrial pseudo-control region and 10 introns from various nuclear genes, and estimated length diversity in 23 microsatellite markers. The European population has expanded since the late Pleistocene, and does not exhibit signs of a recent population bottleneck. The global genetic diversity in Europe was rather similar to that detected in other similar species. Microsatellites suggested shallow but significant differentiation between the four extant populations in Estonia, Poland, Belarus and Russia (Upper Volga region) populations, but introns and mtDNA showed that only the Estonian population differed from the others. Mitochondrial diversity was highest in the northernmost Estonian population, introns suggested lower diversity in Upper Volga, microsatellites indicated equal diversity among populations. A recent bottleneck was detected in Poland, which is consistent with the observed repopulation of the region. We conclude that significant gene flow and high genetic diversity are retained in the fragmented Greater Spotted Eagle populations; there is currently no need for genetic augmentation in Europe.

Genetic determination of migration strategies in large soaring birds: evidence from hybrid eagles.

The relative contributions of genetic and social factors in shaping the living world are a crucial question in ecology. The annual migration of birds to their wintering grounds and back provides significant knowledge in this field of research. Migratory movements are predominantly genetically determined in passerine birds, while in large soaring birds, it is presumed that social (cultural) factors play the largest role. In this study, we show that genetic factors in soaring birds are more important than previously assumed. We used global positioning system (GPS)-telemetry to compare the autumn journeys and wintering ranges of two closely related large raptorial bird species, the greater spotted eagle Clanga clanga and the lesser spotted eagle Clanga pomarina, and hybrids between them. The timing of migration in hybrids was similar to that of one parental species, but the wintering distributions and home range sizes were similar to those of the other. Tracking data were supported by habitat suitability modelling, based on GPS fixes and ring recoveries. These results suggest a strong genetic influence on migration strategy via a trait-dependent dominance effect, although we cannot rule out the contribution of social interactions.