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Open access

József Gyurácz, Gábor Horváth, Tibor Csörgõ, László Bank and Sándor Palkó

Influence of macrosynoptic weather situation on the autumn migration of birds in Hungary

In the study we have examined the relation between the European macrosynoptic weather situation and the number of birds captured a day at four Hungarian ringing stations during the autumn migration. Along the research we examined the data of 32 809 individuals of 8 species using different migration strategies. Using the daily capture data at the four stations we constructed the migration diagrams for each year. We chose the migration peak days within ten-day periods and examined how these peak days or their preceding days are distributed over Péczely's macrosynoptic weather situations. Comparing the 8 bird species no significant difference in distribution of the peak days over the macrosynoptic weather situations was found (ANOVA: F7,376 = 1.81, p = 0.084). 85% of the migration peak days for all the species were connected with anticyclones, 10% with meridional cyclone / cold front situation and 5% with other cyclonic ones. The most frequent weather situation on the migration peak days was central anticyclone, which occurred in 61 cases.

Open access

Gábor Sándor and György Szabó

Abstract

Soil profiles of the city centre of Debrecen were investigated in order to examine their properties and investigate the vertical distribution of heavy metals as a measure the anthropogenic activity. During the laboratory work the basic soil features were identified (texture, artefact content, pH, CaCO3, and amounts of organic matter). Furthermore, contents of Pb, Zn, Cu and Co in the soils were measured. Most of the metals showed a strong positive correlation with the humus content and the silt fraction. The soils of the city centre are exposed to a significant anthropogenic effect, therefore the original soil morphologies are usually difficult to identify. The soil profiles are greatly disturbed, which is traceable in the vertical distribution of certain soil features and metal contents.

Open access

Katalin Krenhardt, Gábor Markó, Eszter Szász, Mónika Jablonszky, Sándor Zsebők, János Török and László Zsolt Garamszegi

Summary

Different experiences from the past may have influence on individual’s behaviour through feedback mechanisms that can weaken or preserve the within-individual consistency of behavioural traits. Here, we aimed to find evidence for such feedback mechanisms that may operate on risk-taking behaviour via the effect of former experience to potential predation events in male Collared Flycatchers (Ficedula albicollis). We predicted that risk-taking of males would decrease after experiencing a predator’s attack in previous breeding seasons (negative feedback). We assessed risk-taking by flight initiation distance (FID) that is the distance at which an individual flees from an approaching predator, which was estimated for 234 individuals from different breeding seasons. Information on predation experience (i.e. occurrence of nest predation, the incidence of capture by human observers) was available from our long-term database on individual life histories. In a horizontal approach, we found no difference in FID when comparing males with former experience to predation with males naive to predators. A longitudinal approach relying on the repeated tests of the same individuals from different years yielded analogous results, we could not show a significant change in the risk-taking behaviour of the males as a consequence of experience to predation in past years. However, we found that individuals systematically took less risk over the years, which might be a consequence of acquiring general experience with age.

Open access

Csongor Freytag, Sándor Attila Pabar, Zita Demeter, Ádám Simon, Anna Resetár, Attila V. Molnár, Gábor Sramkó and Csaba Máthé

Abstract

We aimed to produce tissue cultures and plant regeneration from endangered Crocus species: C. scepusiensis, C. tommasinianus, C. vittatus (“Verni” series of the genus) and C. banaticus. For initiation of cultures we used a plant growth regulator (PGR) combination used for in vitro culture of saffron and its relatives: 10 mg L-1 α-naphthaleneacetic acid (NAA) and 1 mg L-1 6-benzyladenine (BA). Shoot tips of young seedlings (C. scepusiensis) and corms (for the rest of species) were used as explants. C. scepusiensis explants developed into organogenic calli. On media with decreased NAA and with or without increased BA concentration, calli produced stigma-like structures and/or shoots and whole plants. In the other species, callus initiation medium induced callus formation with abundant somatic embryos. In C. tommasinianus, embryos developed shoots when auxin content of medium was decreased. In C. banaticus, a decrease of auxin with or without an increase in cytokinin content led to shoot or whole plant regeneration, as in C. scepusiensis. In the case of C. vittatus and C. banaticus, initiation and/or maintenance of cultures on indole-3-butyric acid (IBA) and increased sucrose concentration stimulated whole plant regeneration and in vitro cormlet development. C. scepusiensis and the rest of cultures (organogenic vs. embryogenic) differed at the biochemical level: C. scepusiensis cultures had higher (yet still low) enzymatic antioxidant (catalase, peroxidase) activities. With respect to catalase isoenzyme patterns, C. banaticus was different from the rest of cultures, demonstrating its distinct taxonomical position. Besides germplasm preservation use of the present cultures, they have a potential biotechnological value.