Spatial and temporal differences in migration strategies among endangered European Greater Spotted Eagles Clanga clanga

Summary Understanding connectivity between migratory bird breeding and wintering grounds is essential for range-wide planning of conservation activities. We used GPS tracking to explore the migration of 28 ‘Endangered’ Greater Spotted Eagles, Clanga clanga from three remaining European breeding populations towards their wintering range, and to identify population and sex-specific patterns in selection of wintering sites. The tracked eagles wintered in three continents, 46% in Africa (mostly Eastern Sahel), 43% across southern Europe (mostly Greece) and 11% in Asia (the Middle East). Migratory connectivity was weak (rM = 0.16), and the population spread across the wintering range was large (1,917 km). The three studied populations differed in their migration strategy, with northerly, Estonian breeders all wintering in Southern Europe, and Polish and Belarusian breeders divided between Southern Europe and Africa. Migration strategy was different between Belarusian males and females, with males more likely to winter in Africa than Europe, and on average, migrating 2,500 km further south than females. Migration to Africa took longer, but was partly compensated by higher migration speeds. Greater Spotted Eagles wintered in wetland sites throughout their wintering range, with 15 of 29 birds wintering in internationally or nationally protected sites (including 12 Ramsar sites). Nearly a third of European winterers stayed in the same Greek national park, perhaps indicating a limitation of suitable sites in Europe due to wetland loss or degradation. This highlights the importance of protected wetlands to this species, but also shows their vulnerability to future wetland degradation. Only two of 14 wintering sites in Africa were under protection, showing a potential mismatch between protection of females and males in their wintering grounds.

Snow Buntings Maintain Winter-Level Cold Endurance While Migrating to the High Arctic

Arctic breeding songbirds migrate early in the spring and can face winter environments requiring cold endurance throughout their journey. One such species, the snow bunting (Plectrophenax nivalis), is known for its significant thermogenic capacity. Empirical studies suggest that buntings can indeed maintain winter cold acclimatization into the migratory and breeding phenotypes when kept captive on their wintering grounds. This capacity could be advantageous not only for migrating in a cold environment, but also for facing unpredictable Arctic weather on arrival and during preparation for breeding. However, migration also typically leads to declines in the sizes of several body components linked to metabolic performance. As such, buntings could also experience some loss of cold endurance as they migrate. Here, we aimed to determine whether free-living snow buntings maintain a cold acclimatized phenotype during spring migration. Using a multi-year dataset, we compared body composition (body mass, fat stores, and pectoralis muscle thickness), oxygen carrying capacity (hematocrit) and metabolic performance (thermogenic capacity – Msum and maintenance energy expenditure – BMR) of birds captured on their wintering grounds (January–February, Rimouski, QC, 48°N) and during pre-breeding (April–May) in the Arctic (Alert, NU, 82°). Our results show that body mass, fat stores and Msum were similar between the two stages, while hematocrit and pectoralis muscle thickness were lower in pre-breeding birds than in wintering individuals. These results suggest that although tissue degradation during migration may affect flight muscle size, buntings are able to maintain cold endurance (i.e., Msum) up to their Arctic breeding grounds. However, BMR was higher during pre-breeding than during winter, suggesting higher maintenance costs in the Arctic.

Evidence for seasonal changes in population structure of Reed Buntings (Emberiza schoeniclus) in the Lake Neusiedl Region: a stable-isotope approach

Migrating species and populations are affected by conditions existing across large geographical scales. The degree to which populations mix at stop-over sites and wintering grounds is variable and can involve important fitness consequences. Thus, the link between breeding and wintering grounds and seasonal shifts in population structure are important to understand population demographics, local adaption and diversification patterns. This work aims to infer migration patterns and population connectivity in the Reed Bunting (Emberiza schoeniclus) community of a Ramsar-designated wetland, Lake Neusiedl, Seewinkel, Austria. Stable isotope markers (hydrogen, δ2H, carbon, δ13C) in feathers were analyzed to assign individuals to a specific breeding or natal area. Based on the geographic assignment, birds were compared with respect to their ecomorphological traits and their habitat selection (large reed bed versus more open habitat at shore of an alkaline lake) during winter to assess potential ecological differences and possibly associated morphological divergence. Stable isotope data revealed that the local Reed Bunting community undergoes seasonal changes in population structure. Three different populations that vary in their δ2H signature and to some extent in morphological characteristics as well as in δ13C values were identified. Indications for differential migration related to age and/or sex were additionally found, since males and females as well as first-year birds and adults showed remarkable differences in their traits and feather isotope values. δ2H values diverged significantly between these groups in both age and sex classes and birds with highest feather δ2H values were considered to represent the local breeding population at Lake Neusiedl and possibly also Reed Buntings from close surroundings. Moreover, this group had the highest δ13C values in first-year individuals as well as in adults. In both sex classes, the assignment of Reed Buntings to different populations was ultimately possible due to differences in bill shape with residents being characterized by more massive bills than individuals belonging to populations visiting the study area only during migration or for wintering. During winter, beak shape and feather δ2H and δ13C values differed significantly between birds caught in the reed stand of Lake Neusiedl and those captured near the salt pan, hence, indicating differential habitat selection among co-occurring populations during winter. These findings suggest that morphological attributes, such as bill shape and size as well as linked adaptations to different food sources play a decisive role for niche segregation among wintering populations. The results provide evidence that different populations mix during migration and during winter at Lake Neusiedl and the extent to which they are specialized to a specific habitat varied.

New Data in the Research of Settlements of the Saka Time in Central Kazakhstan

The article is devoted to an overview of the results of new studies of the Saka era settlements discovered in the eastern regions of Central Kazakhstan. The source base of modern research was made up of over 70 settlements found over the past 20 years. The author attributes these settlements to the tasmola culture of Central Kazakhstan and dates them within the framework of the 8th — 5th centuries BC. Archaeozoological, traceological, and carpological analyzes are being carried out based on the materials from the excavations of the Kulzhan-1 and Abylai settlements and other sites carried out in recent years. According to the author, the settlements of Central Kazakhstan of the Saka era were the winter habitats of the tribes of the Tasmola culture. Materials from over 50 Kazakh wintering sites make it possible to draw ethnographic data. A comparative study of these sites has shown that the topography of the Kazakh wintering grounds and Saka settlements coincide. Keywords: Central Kazakhstan, tasmola culture, Saka era, settlements, Kazakh wintering grounds, multidisciplinary research

Current state of ichthiocenosis, species composition and fish populations in small river basins from Pripyatske Polissiya of Ukraine — ways of rehabilitation and restoration

Purpose. To study ichthyocenosis, species composition and current state of fish populations in small river basins from Pripyatske Polissiya of Ukraine, to propose the ways of their rehabilitation and restoration. Methodology. The study analysed data for last 60 years on the results of monitoring catches of fish wintering grounds of the first-order tributaries of the Pripyat River — right-bank rivers (rivers Slovechna, Sluch, Tina), as well as more than 300 flood plain lakes of the Desna River. Fish were caught by expeditionary methods using boats, seines and gill nets before ice formation in November-December. Methods generally accepted in ichthyology and ecology as well as surveys of anglers were used. Findings. The study showed the crisis state of the Upper Dnipro region, which was confirmed by the data on a significant decrease in fish productivity. The reasons for this are: non-observance of the basin approach in nature management, ineffective nature conservation measures, lack of measures for the rehabilitation of "natural localities" for the reproduction of native ichthyofauna. It should be noted that the creation of National Reserves and NaturalParks (Shatskyi, Pripyat-Stokhid, Rovenskyi, Polesskyi, Menskyi, etc.) did not significantly affect the general state of the problem, and rather has a declarative meaning. Since, although they still have some places with good reproduction conditions for native flora, fauna and valuable natural landscapes, however, this does not affect the general ecological situation in the river network. This is due to the fact that the surface runoff from territories without destructive human impact, which form the hydrochemical regime, is a fraction of a percent of the total amount. Accordingly, the following is observed: shallowing of river channels, smoothing of the bottom, siltation of wintering grounds, decrease in breeding stock number, degradation of spawning grounds and a lack of artificial stocking measures. This leads to a 10-fold decrease in fish catches in small rivers from Pripyatske Polissiya of Ukraine over the past 20 years. Originality. The study examines the problem of the relationship between the accessary river network and the fish productivity of rivers, including the Kуiv (receiving the flow of the DniprоRiver) and the upper reaches of the Kaniv (receiving the flow of the DesnaRiver) reservoirs. It outlines their role in the functioning of the trilateral natural complex located on the territory of Ukraine, Belarus and Poland. The possibility of creating the ichthyo-ecological reserve "Verhniy Dnipro on the territory of Ukraine on the base of existing protected areas within the Pripyat and Desnyansky hydroecological corridors is analysed. Practical Value. It has been proved that the creation of the "Verhniy Dnipro" will allow not only creating a stable base for the natural reproduction of native ichthyofauna in the upper reaches of the Dnipro reservoir cascade but providing high-quality water to the population of Kyiv and the Kyiv region. The concept of rehabilitation of reproduction and conservation of biodiversity of native ichthyofauna in the river network is proposed to maintain the stability of the biosphere, the implementation of which requires little funds. Keywords: ichthyofauna, ichthyocenosis, ichthyoecosystem, restoration of spawning grounds, PripyatRiver, DniproRiver, DesnaRiver.

Probing of heavy metals in the feathers of shorebirds of Central Asian Flyway wintering grounds

The study is intended to deliver the incidence of heavy metals in the feathers of shorebirds from two important Central Asian Flyway (CAF) migratory shorebirds wintering sites such as the Point Calimere Wildlife Sanctuary (PWLS) and Pichavaram Mangrove Forest (PMF), India. Feathers of fifteen species of shorebirds and seven different metals viz., Cu, Cr, Co, Pb, Hg, Ni and Zn were analyzed. Zn was highest in Dunlin, Little-ringed Plover, Marsh Sandpiper, and Common sandpiper, Ni showed highest in Little ringed plover, and Common sandpiper, Co, Cr, and Cu were maximum in Little stint, Marsh sandpiper, and Dunlin, respectively. The Hg was higher in Black-winged stilt, Common redshank, Curlew Sandpiper, Eurasian curlew, Lesser Sand-plover, Temminck’s stint, Kentish plover, Spotted redshank, and Wood sandpiper, the Pb found highest in Kentish plover, Painted stork, Spotted redshank, Wood sandpiper, Eurasian Curlew, and Lesser sand-plover. The concentration of metals showed significant variations among the species of shorebirds studied (P < 0.001). The mercury negatively correlated with the other metals than the other six metals studied in both the wetlands. The order of metal concentration in the feathers of shorebirds was Zn > Ni > Co > Cr > Cu > Pb > Hg. Nevertheless, the current study revealed that the level of metals in the shorebirds is alarming; since the PWLS and PMF are located along the CAF routes, it needs intensive studies on various pollutions to manage both the resident as well as migratory shorebirds.

Sharing wintering grounds does not synchronize annual survival in a high Arctic seabird, the little auk

Sharing the same wintering grounds by avian populations breeding in various areas may synchronize fluctuations in vital rates, which could increase the risk of extinction. Here, by combining multi-colony tracking with long-term capture-recapture data, we studied the winter distribution and annual survival of the most numerous Arctic seabird, the little auk Alle alle. We assessed whether little auks from different breeding populations in Svalbard and Franz Josef Land use the same wintering grounds and if this leads to synchronized survival. Our results indicate that birds from the Svalbard colonies shared similar wintering grounds, although differences existed in the proportion of birds from each colony using the different areas. Little auks from Franz Josef Land generally spent the winter in a separate area, but some individuals wintered in the Iceland Sea with Svalbard populations. Survival data from 3 Svalbard colonies collected in 2005-2018 indicated that sharing wintering grounds did not synchronize little auk annual survival rates. However, it is clear that the Iceland Sea is an important wintering area for little auks, and environmental changes in this area could have widespread impacts on many populations.