Four piscivorous fishes such as pike, Esox lucius, European catfish, Silurus glanis, pikeperch, Sander lucioperca, and Eurasian perch, Perca fluviatilis, co-occur in Kaniv Reservoir (Ukraine). In total, 47 food items were identified in their diets including remains of fish and invertebrates. Sixteen prey items were identified in pike diet including 15 fish species; 33 prey items in European catfish diet smong which 20 fish species; 21 prey items in pikeperch diet, among which 18 fish species; and 28 prey items in perch diet, among which 12 fish species. The most important prey for pike were roach, Rutilus rutilus (%IRI = 25,9 %), Prussian carp, Carassius gibelio (34,7 %), and perch (18.4 %); for catfish - roach (55,5%) and perch (20,6 %); for pikeperch - roach (52,8 %) and perch (34.1 %); and for perch - monkey goby, Neogobius fluviatilis (85.7 %). Highest diet overlap indices were observed between catfish and pikeperch (84.8 %) while the lowest between catfish an perch (33.7 %). No significant difference was observed between the average sizes of fish prey in the stomachs of pikeperch and European catfish (t-test, P >0.05) but there were significant differences between all other pair of piscivorous species (t-test, P <0.001).
Long-term spring phenological instants of 57 migratory bird species, i.e. arrival in summer visitors and departure in winter visitors, were recorded in South Moravia (Czech Republic) from 1952 through 2001 and evaluated for annual correspondence with the North Atlantic Oscillation (NAO) weather system. The migration instants occurred significantly earlier following positive winter/spring NAO index values (causing periods warmer than normal in Europe) in a number of short-distance migrants with a European winter range (e.g., Alauda arvensis, Columba palumbus, Corvus frugilegus, Motacilla alba, Phoenicurus ochruros, Phylloscopus collybita, Serinus serinus, Sturnus vulgaris, Vanellus vanellus), whereas they did not correlate with NAO in most long-distance migrants having a sub-Saharan winter range (e.g., Acrocephalus spp., Anthus trivialis, Apus apus, Cuculus canorus, Delichon urbica, Ficedula albicollis, Hippolais icterina, Hirundo rustica, Jynx torquilla, Lanius collurio, Locustella spp., Muscicapa striata, Oriolus oriolus, Phylloscopus sibilatrix, Riparia riparia, Streptopelia turtur, Sylvia spp.). The winter/spring (especially February and March) NAO conditions thus affect the migration timing of short-distance migrants that winter in western or southern Europe, and could explain their earlier than normal arrival that had been observed in Europe since the 1980s.
We studied the amphibian breeding migration into an old established (the beginning of the 1990s) pond and a new one (2007), using drift fences in 2008-2011. The two ponds were located at a distance of about 0.5 km from one another in a post-agricultural landscape in the Mazurian Lakeland, north-eastern Poland. We examined the community structure and migration rates of adults and juveniles. The amphibian breeding communities were similar in the two ponds in each year. The moor frog Rana arvalis was the most
common species and comprised between 35 and 55 % of all adult amphibians migrating to both ponds. The new pond was colonized by adult amphibians in the first spring after its creation. In the second year, the amphibian migration rates doubled in the new pond and remained stable over the next two years. However, during the entire period of the study the old pond was a more attractive spawning site than the new pond, when measured by the number of migrating individuals of all recorded species. Despite some annual variation, there were no significant differences between the ponds in terms of the sex structure, mean body mass or migration timing of the predominant amphibian species. The most probable explanation for the observed differences in the rates of migration is breeding site fidelity.
A study of home range and habitat use was carried out on grey partridge (Perdix perdix) in a high density population (24–33 pairs /km2) in the south-west part of Praha, Czech Republic from 1997 to 1999. Radiotracking of individual partridge was used in the study (n = 11). Breeding period (March – June 15) and post-breeding period (June 16 – October) were analysed separately. Home range size (minimum convex polygon 95%) in the breeding period averaged 3.7 ha with a significant increase up to 8.7 ha in the post-breeding period. The majority of partridge ranges were located within dominant crop fields and idle habitats (unmanaged early stages of plant succession) referred to as weeds. Both high population density and small individual home ranges may result from the wide availability of weeds, whose attractiveness was probably due to availability of nesting sites, sufficient food supply for both partridge chicks and adults and adequate escape cover. Despite a high population density, there is an indication of little home range overlaps between pairs during the breeding period.
Vědecký časopis Nature publikoval 14. listopadu 2013 článek Dráha, struktura a původ Čeljabinského tělesa (The trajectory, structure and origin of the Chelyabinsk asteroidal impactor) autorského týmu pod vedením astronomů z Oddělení meziplanetární hmoty Astronomického ústavu AV ČR. Pád malé planetky nad Ruskem 15. února 2013 (viz AB 3/2013) vyvolal celosvětovou pozornost a mnohé vědecké týmy nyní vzácnou událost analyzují. Čeští astronomové se jí věnují od počátku a již 23. února jako první na světě rigorózní metodou spočítali dráhu tělesa. and Pavel Spurný, Jiří Borovička.