The aim of our study was to analyse red blood cells from the high-altitude avian species alpine accentor (Prunella collaris). We caught 79 alpine accentors in the High Tatra Mountains (the West Carpathians, Slovakia) from 2001 to 2008. Blood samples were collected from the vena ulnaris cutanea. The cells and nuclei of juveniles tend to be wider and larger while adults, especially males, tend to have elongated (narrow) cells. The largest erythrocytes were found in winter and the smallest in summer, in June. Red blood cells with larger, elongated nuclei but overall smaller in size occurred at the beginning and the end of the breeding season, while larger, rounded cells with smaller nuclei were found in the middle of the breeding season. This kind of reshaping of erythrocytes of alpine accentors in summer is probably a response to hypoxia and elevated summer temperature in high mountains. As regards the length/width ratio, in August and September, erythrocytes were more elongated (both cell and nucleus) than in the other months. This study is probably the first assessment of seasonal effects on size and shape of red blood cells of bird species permanently living and breeding at high altitudes of the Palearctic mountains.

The birds inhabiting the high-altitude mountains have several physiological adaptations to environmental conditions. In this study, we try to investigate if are the morphological changes in erythrocytes caused by adaptation to a different condition in Eurasian mountain ranges and molt period. In a comparison of morphology of erythrocytes in alpine accentors from three different regions (Central Tian Shan (Kyrgyzstan), the Rila Mountains (Bulgaria) and the High Tatras (Slovakia)) variations were found in size and shape. Birds from the High Tatras had the largest and most elliptical cells, while erythrocytes from Tian Shan´s birds have the smallest and roundest shape. We also found that individuals from spatially separated populations of alpine accentors vary in size. The largest birds are found in the High Tatras, with smaller birds in the Rila Mountains and the smallest in the Tian Shan. Changes in erythrocyte morphology were studied in birds during the molt period (September–October). The cells elongate during the molt and do not reach their pre-molt size even after the molt. These morphology differences likely reflect their adaptation to environmental conditions such as climate and temperature as well as individual metabolic processes during the molt and preparation for autumn migration. In addition to their essential function (respiratory gas transport), nuclear erythrocytes can also participate in the transcription and translation of proteins, extending their other functions. Thus, it seems that changes in morphology must not affect these functions.

The determination of potentially toxic element concentrations in fish is an important topic from the point of view of both nature conservation and human consumption. The aim of this study was to assess the concentrations of S, K, Ca, Cr, Mn, Fe, Zn, Rb, Sr, Mo, and P in benthic and pelagic fish species in the Karatal river, which is fed by melting glaciers from the Dzungarian Alatau in Kazakhstan. In September 2022, 48 fish samples were collected. It has been demonstrated that the accumulation of chemical elements in fish species can be explained by both the physiological parameters of the fish species and the influence of glaciers that feed river habitats. The data presented in this study provide a synergistic view of pollutants affecting fish populations. Benthic fish contained more manganese and strontium than pelagic species, while the mutual accumulation of potassium, chromium, rubidium, and molybdenum was higher in pelagic fish. The synergistic concentration of calcium and phosphorus in pelagic fish was higher than that in benthic species, while the amount of zinc and sulfur was higher in benthic animals. Relatively elevated levels of mercury in fish were found. The study contributes to the discussion about the role of glacial environments in loading pollutants to aquatic systems.