Central Czech Republic Research Articles

Effects of a point source of phosphorus on the arsenic mobility and transport in a small fluvial system

One of the leading causes of As release from streambed sediments into freshwater systems is competition with phosphate. Among important sources of P to the fluvial ecosystems are wastewater treatment plants (WWTP), estimated to account for 25–45% of all P in surface waters. In this paper, long-term effects of discharged phosphorus from a small WWTP on the arsenic mobility were studied in an As-enriched fluvial system (approx. 240 mg/kg) in central Czech Republic. After 7 years of elevated P (≤7.7 mg/L) in the stream water, the total As decreased by 25% and the total P increased by 40% in the sediments downstream (at a distance of 66 m). The results of the chemical extractions and mineralogical analyses indicated that the changes in the concentration were mostly due to the sorption processes in the Fe (oxyhydr)oxides (goethite and hematite). In the downstream samples, the As in these phases decreased two-fold, and P was significantly enriched by 45–140%. Phosphorus was also found precipitated as newly formed Ca phosphates. The stream water monitoring indicated that the discharged P was either sequestered when the levels of dissolved P were high (>2.3 mg/L) or released from the downstream sediments when these levels were low (<∼1.5 mg/L). Meanwhile, As was continuously mobilized from the downstream sediments likely due to (i) the ongoing As desorption from the exterior parts of the Fe (oxyhydr)oxides at high aqueous P levels and (ii) the dissolution of As-bearing Ca phosphates at low dissolved P levels. These findings clearly demonstrate that point sources of P to streams and rivers, such as WWTP, may result in the permanent and long-term release of As from contaminated streambed sediments.

Mismatch between Annual Tree-Ring Width Growth and NDVI Index in Norway Spruce Stands of Central Europe

Presently, the forests of one of the most economically important tree species in Europe—Norway spruce [Picea abies (L.) Karst.]—have been disrupted and are in rapid decline due to a combination of several natural factors: extreme drought, heatwaves, and secondary damage caused by bark beetle outbreaks. The vulnerability of these forests has increased considerably over the past decade, and remote sensing methods can theoretically improve the identification of endangered forest stands. The main objective was to determine the relationship between remotely sensed characteristics of vegetation (using the normalized difference vegetation index—NDVI) and annual tree-ring growth in 180 trees through precipitation and air temperature. The research was conducted at six research plots in lowland spruce forests (319–425 m a.s.l.) in the central Czech Republic. No significant correlation between NDVI and annual ring width was observed. The primary factor limiting radial growth was lack of precipitation in the growing season; subsequently, spruce trees reacted negatively to air temperatures. A higher correlation with NDVI was observed on sites susceptible to drought, but overall, NDVI and RWI did not show similarities. This result describes that NDVI is a poor indicator for identifying low radial growth in Norway spruce stands on non-native localities in the studied area.

Mercury cycling during acid rain recovery at the forested Lesní potok catchment, Czech Republic

AbstractFrom 2011 to 2019, mercury (Hg) stores and fluxes were studied in the small forested catchment Lesní potok (LES) in the central Czech Republic using the watershed mass balance approach together with internal measurements. Mean input fluxes of Hg via open bulk deposition, beech throughfall and spruce throughfall during the periodwere 2.9, 3.9 and 7.6 μg m−2 year−1, respectively. These values were considerably lower than corresponding deposition Hg fluxes reported in the early years of the 21st century from catchments in Germany. Current bulk precipitation inputs at unimpacted Czech mountainous sites were lower than those in Germany. The largest Hg inputs to the catchment were via litterfall, averaging 22.6 and 17.8 μg m−2 year−1 for beech and spruce stands. The average Hg input, based on the sum of mean litterfall and throughfall deposition, was 23.0 μg m−2 year−1, compared to the estimated Hg output in runoff of 0.5 μg m−2 year−1, which is low compared to other reported values. Thus, only ~2% of Hg input is exported in stream runoff. Stream water Hg was only weakly related to dissolved organic carbon (DOC) but both concentrations were positively correlated with water temperature. The estimated total soil Hg pool averaged 47.5 mg m−2, only 4% of which was in the O‐horizon. Thus Hg in the O‐horizon pool represents 72 years of deposition at the current input flux and 3800 years of export at the current runoff flux. Age‐dating by 14C suggested that organic soil contains Hg from recent deposition, while mineral soil at 40–80 cm depth contained 4400‐year old carbon, suggesting the soil had accumulated atmospheric Hg inputs through millennia to reach the highest soil Hg pool of the soil profile. These findings suggest that industrial era intensification of the Hg cycle is superimposed on a slower‐paced Hg cycle during most of the Holocene.

Distribution and pools of mercury in forest soils near recent and historical mercury emission sources in the central Czech Republic

The fate of atmospherically deposited mercury (Hg) was studied in forest soils situated near various Hg anthropogenic emission sources, including chlor-alkali plants, cement production, and pig iron and steel factories in the Czech Republic. Some of these emission sources were more active in the past, while others continue operation with lowered dust and Hg emissions up to the present day. The impact of Hg emission sources on forest soil was assessed with respect to other soil parameters, including organic carbon, soil nitrogen, soil sulfur, and soil oxalate-extractable aluminum and iron concentrations. The site-specific mean Hg concentrations in organic horizons (174–479 μg kg−1) were greater than mean Hg concentrations in mineral soil (15–88 μg kg−1). Site specific mean Hg/C ratios in organic horizons at four study sites ranged from 0.8 to 2.4 μg g−1, while mean mineral soil Hg/C varied from 2.0 to 3.4 μg g−1. Near cement plants, an 8- to 30-cm thick layer composed of dust particles was identified below or mixed with current O and A horizon material (Hg concentrations 122 to 401 μg kg−1). Mean mineral soil pools of Hg (13–24 mg m−2) dominated over the mean organic horizon Hg pools (2–11 mg m−2). Near cement plants and steel works, Hg concentrations and pools in organic horizons and mineral soils were within the range reported from pristine Czech forest soils. Elevated Hg concentrations in organic horizons were found near a chlor-alkali plant. Thermal decomposition analysis indicated that Hg in A horizons at all sites and dust horizons near cement plants was bound similarly to Hg in foliage.

Crossing the Danube: A Comparative Study of Central European and American Access-to-Information Laws

The Freedom of Information Act in the United States was a relatively rare access-to-information, or ATI, statute when passed in 1966, but it inspired many similar statutes in nations around the world. This article conducts a comparative study focused on Central Europe, with Poland, Hungary and Czech Republic selected as nations that illustrate ATI philosophy and enforcement in that region. These nations have important similarities but also interesting differences caused by current political trends and local concerns that make each unique in its own right. Ultimately, this study seeks to determine whether these nations have adopted not just the text but also the spirit of transparency embodied in FOIA, with a particular focus on that region’s much different legal and political structures as compared to the United States and Western Europe.

Modelling of Soil Erosion and Accumulation in an Agricultural Landscape—A Comparison of Selected Approaches Applied at the Small Stream Basin Level in the Czech Republic

This article deals with the modelling of erosion and accumulation processes in the contemporary cultural landscape of Central Europe. The area of interest is the headwater part of the small stream catchment—the Kopaninský Stream in central Czech Republic. It is an agricultural and forest–agricultural landscape with a relatively rugged topography and riverbed slope, which makes the terrain very vulnerable to water erosion. The main aim of this article is to compare the results of four selected soil erosion and sediment delivery models, which are currently widely used to quantitate the soil erosion and sediment accumulation rates, respectively. The models WaTEM/SEDEM, USPED, InVEST and TerrSet work on several different algorithms. The model outputs are compared in terms of the total volume of eroded and accumulated sediment within the catchment per time unit, and further according to the spatial distribution of sites susceptible to soil loss or sediment accumulation. Although each model is based partly on a specific calculation algorithm and has different data pre-processing requirements, we have achieved relatively comparable results in calculating the average annual soil loss and accumulation. However, each model is distinct in identifying the spatial distribution of specific locations prone to soil loss or accumulation processes.

Are atmospheric PBDE levels declining in central Europe? Examination of the seasonal and semi-long-term variations, gas–particle partitioning and implications for long-range atmospheric transport

Abstract. This study presents multi-year monitoring data on atmospheric polybrominated diphenyl ethers (PBDEs) in central Europe. Air was sampled on a weekly basis at a background site in the central Czech Republic from 2011 to 2014 (N = 114). Σ8PBDEs (without BDE209) total (gas and particulate) concentrations ranged from 0.084 to 6.08 pg m−3, while BDE209 was at 0.05–5.01 pg m−3. BDE47, BDE99 and BDE183 were the major contributors to Σ8PBDEs.Overall, the atmospheric concentrations of individual PBDEs were controlled by deposition processes, meteorological parameters and long-range atmospheric transport. Regarding gas–particle partitioning, with the exception of BDE28 (gaseous) and BDE209 (particulate), all congeners were consistently detected in both phases. Clear seasonal variations with significantly higher measured particulate fraction (θmeasured) in winter compared to summer was found for all PBDEs except BDE209. For example, while the average θmeasured of BDE47 was 0.53±0.19 in winter, this was only 0.01±0.02 in summer. Similarly, for BDE99, θmeasured was 0.89±0.13 in winter, while it was only 0.12±0.08 in summer. The observed gas–particle partitioning coefficient (Kp, in m3 µg−1) was compared with three model predictions, assuming equilibrium or a steady state. None of the models could provide a satisfactory prediction of the partitioning, suggesting the need for a universally applicable model.Statistically significant decreases of the atmospheric concentrations during 2011–2014 were found for BDE99, 100, 153 and 209. Estimated apparent atmospheric halving times for these congeners ranged from 2.8 (BDE209) to 4.8 (BDE153) years. The results suggest that photolytic debromination to lower brominated congeners may significantly influence PBDE concentration levels and patterns in the atmosphere.

Experimental determination of the flood wave transformation and the sediment resuspension in a small regulated stream in an agricultural catchment

Abstract. This paper presents the methodology used for artificial flood experiments conducted in a small artificial, trained (regulated) channel on the Nučice experimental agricultural catchment (0.5 km2), central Czech Republic, and the results of the experiments. The aim was to monitor the transformation of the flood wave and the sediment transport within the channel. Two series of experiments were carried out in contrasting initial conditions: (a) in September, when the stream banks were dry, the baseflow was negligible, and the channel was fully overgrown with vegetation; and (b) in March, when the stream banks were almost water saturated, the baseflow was above the annual average, and there was no vegetation present. Within each campaign, three successive flood waves, each with an approximate volume of 17 m3 and peak flow of ca. 40 L s−1, were pumped into the upper part of the catchment drainage channel. The transformation of the flood wave and the sediment transport regime within an approximately 400 m long channel section were monitored by measuring the discharge, the turbidity, and the electrical conductivity in three profiles along the stream. On the basis of the results, it was concluded that there is a considerable amount of deposited sediment, even in the well-trained and straight channel that can be re-mobilized by small floods. Part of the recorded sediment therefore originates from the particles deposited during previous soil erosion events. The flood waves initiated in dissimilar instream conditions progressed differently – we show that the saturation of the channel banks, the stream vegetation and the actual baseflow had a strong influence on the flood transformation and the sediment regime in the channel. The sediment moves quickly in winter and early spring, but in the later part of the year the channel serves as a sediment trap and the resuspension is slower, if dense vegetation is present.

Atmospheric station Křešín u Pacova, Czech Republic – a Central European research infrastructure for studying greenhouse gases, aerosols and air quality

Abstract. Long-lasting research infrastructures covering the research areas of atmospheric chemistry, meteorology and climatology are of highest importance. The Atmospheric Station (AS) Křešín u Pacova, central Czech Republic, is focused on monitoring of the occurence and long-range transport of greenhouse gases, atmospheric aerosols, selected gaseous atmospheric pollutants and basic meteorological characteristics. The AS and its 250 m tall tower was built according to the recommendations of the Integrated Carbon Observation System (ICOS) and cooperates with numerous national and international projects and monitoring programmes. First measurements conducted at ground started in 2012, vertical profile measurements were added in 2013. A seasonal variability with slightly higher autumn and winter concentrations of elemental and organic carbon was revealed. The suitability of the doubly left-censored Weibull distribution for modelling and interpretation of elemental carbon concentrations, which are often lower than instrumental quantification limits, was verified. Initial data analysis also suggests that in summer, the tower top at 250 m is frequently above the nocturnal surface inversions, thus being decoupled from local influences.

Insect community on Jurinea cyanoides (Asteraceae), a plant species protected under NATURA 2000

AbstractThe plant Jurinea cyanoides (L.) Reichenbach (Asteraceae), protected under the European Commission Directive on the conservation of natural habitats and of wild fauna and flora (92/43/EEC), is critically endangered in Central Europe. The centre of its continuous range of distribution is in Ukraine and in a part of European Russia. Natural isolated populations have refugial distribution in the Czech Republic and Germany. Interactions of insects from different feeding guilds (i.e., phytophages, pollinators, parasitoids, predators) with J. cyanoides were studied in central Ukraine, Czech Republic and Germany. The insect community identified on J. cyanoides and differences in its composition on robust populations of plant in contrast to sparsely populated periphery of its range are discussed. Altogether 78 species belonging to six orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera and Neuroptera) were recorded. Larvae of the pyralid moth (genus Dioryctria), tephritid fruit flies (Acanthiophilus helianthi), and several polyphagous Heteroptera species are identified as main taxa feeding on inflorescences and seeds of J. cyanoides, with a potential to reduce the plant’s sexual reproduction. The impact of phytophagous insects is, however, considered only a secondary reason for the decline of the Czech populations of J. cyanoides on which a fairly low number of insect species were recorded in comparison with Ukraine and Germany; habitat loss and inbreeding effect are probably major negative factors. Several new host plant-insect and host-parasitoid associations are reported for insects on J. cyanoides.

The evaluation of geological structures by the vector analysis of valley axes

The paper describes the methodology of evaluating geological structures by the vector analysis of valley axes. Both geological structures and valley axes were determined by the azimuth and the dip which corresponds with the angle of the slope in the selected catchment in the central Czech Republic. The determination of the dip of valley axes has formed a base for the quantitative classification of valley axes analogous to geological structures. The following five types of valley axes were distinguished: sub-horizontal, gently inclined, moderately inclined, steeply inclined and sub-vertical. The orientations of both the valley axes and the geological structures were evaluated by the construction of outline diagrams in the programme Spheristat. The directions of valley axes were compared with geological structures by the statistical relationship using the chi square test. The directions of sub-horizontal valley axes correspond with the dip azimuth of foliations in contrast to the dip azimuth of joints in the model area. The evaluation of geological structures by the vector analysis of valley axes is practicable in all kinds of landscape.

Diel variation of arsenic, molybdenum and antimony in a stream draining natural As geochemical anomaly

The Mokrsko Stream in the central Czech Republic is an oxic and slightly alkaline stream that drains a natural As geochemical anomaly. Although long-term monitoring has characterized the general seasonal trends in trace element concentrations (i.e., As, Mo, Cu, Zn) in this stream, little is known about solubility controls and sorption processes that influence diel cycles in trace element concentrations. Trace elements (including As species, Cu, Mn, Mo, Pb and Sb) and other parameters were monitored over two 24-h periods in unfiltered and filtered (0.1μm) samples collected in August 2010 and June 2011. Copper and Pb were predominantly (>92% of the mass) associated with the particulate fraction (>0.1μm). Arsenic, Mo and Sb were predominantly (>88% of the mass) in the “dissolved” (<0.1μm) form. Particulate-associated elements displayed up to a factor of 13 differences between minimum and maximum concentrations, most likely due to increased streamflow related to rainfall events. Dissolved concentrations of the trace metal cations (Cu, Fe, Mn and Pb) were consistently low and displayed no diel trends. Dissolved As(V), Mo and Sb varied on a diel cycle, with increased concentrations (up to 36%) during the late afternoon and decreased concentrations during the nighttime. Diel trends in trace anionic elements are explained by temperature-dependent sorption, as the diel changes in pH during base flow were very small (0.07 std. units). Very low concentrations of As(III), which have been shown to vary in a diel cycle, were attributed to enhanced hydraulic exchange with As(III)-rich hyporheic water during rainfall events.

Identification of a new unusual length polymorphism of the nucleocapsid protein in porcine reproductive and respiratory syndrome virus

All twenty-nine PRRSV ORF7 nucleotide sequences obtained from clinical samples originating from the three Central European countries Austria (n=7), Czech Republic (n=12), and Slovakia (n=10) belonged to type 1, subtype I (EU-1). Twenty-seven sequences encoded the typical length of the nucleocapsid protein composed of 128 amino acids. Two genetically identical ORF7s of PRRSV originating from a single farm in Slovakia showed a new length polymorphism of the nucleocapsid protein comprising 132 amino acids.

Mineral inclusions in pyrope from garnet peridotites, Kolín area, central Czech Republic

Mineral inclusions were studied with emphasis on the relatively abundant acicular, preferentially oriented rutile in pyrope from the Kolin area. In contrast, rutile inclusions are rare or absent at two other, currently exploited pyrope deposits in northern Bohemia (Podsedice and Vestřev). The aim was also to obtain the first analytical information on variety of other mineral inclusions, some of which were previously indicated in the literature based on qualitative gemmological observation. Host garnet composition shows limited variation with Prp 67.9–71.6, Alm 13.3–18.9, Grs 2.0–7.5 and Uvr 2.6–9.6 mol. %. Electron microprobe study resulted in identification of the following mineral inclusions in pyrope: rutile, magnesian ilmenite, olivine, magnesite, enstatite, pargasite, phlogopite, barian phlogopite, spinel, and a probable crichtonite-series? mineral. Apatite, Ni-sulphide and chalcopyrite were identified based on qualitative spectra. Published Sm-Nd mineral ages point to the presence of two age groups of the Variscan garnet peridotites in the Moldanubian Zone and adjacent units in the Bohemian Massif, i.e. the “neo-Variscan” (~ 339 Ma), and the “palaeo-Variscan” (370–377 Ma). In the Kolin area, the Becvary body was dated at 377 ± 20 Ma. This raises a question, whether the “palaeo-Variscan” garnet peridotites of the Kolin area carry some mineralogical record of protracted annealing or repeated heating, which may have occurred between the two Variscan events. Information from garnet inclusions does not indicate for the Kolin peridotites a history of recycling of older peridotites with pre-Variscan crustal residence. Average TiO2 contents in pyrope from the Kolin area (0.37 wt. %) compare with 0.46 wt. % TiO2 in Vestřev pyropes and 0.52 wt. % TiO2 in Podsedice pyropes (northern Bohemia). This suggests that the relatively low Ti content in Kolin pyrope may be in part due to Ti unmixing in the form of oriented acicular rutile. The data from the present study point to the potential of mineralogical comparative studies on peridotites from individual HP units of the Bohemian Massif.

Changes in Mercury Deposition in a Mining and Smelting Region as Recorded in Tree Rings

Metal mining and processing in the central Czech Republic has led to the contamination of surrounding soils and vegetation. In this study, Hg concentrations were measured in spruce (Picea abies L.) and beech (Fagus sylvatica L.) tree rings to monitor historical Hg deposition in the area. The highest Hg concentrations were found in spruce at an HgS smelting contaminated site (up to 15 ng g−1), probably reflecting smelting activities at the end of the nineteenth century. In the vicinity of a Pb smelter, Hg concentrations increased from the 1950s to maxima (up to 8.4 ng g−1) in the 1970s, corresponding with a peak of metallurgical production and smelter emissions in the mid 1970s. A decreasing trend in Hg concentrations since the 1980s was probably related to improvements in flue gas cleaning technologies. The beech trees, which grow at a site between two smelters and range in age from 150 to 220 years, seem to reflect deposition from both point sources. Mercury levels in beech trees were lower, that resulting from their greater distance from pollution sources, but the concentration trend was strongly correlated with metal production. Analysis of nutrient elements (Ca, Mg, K and Mn) in wood revealed environmental changes related to acid deposition, but a relation between concentration trends of nutrients and Hg was not found. This study shows that tree rings may be a good record of Hg deposition in areas affected by ore mining and smelting. Nevertheless, further investigation of Hg cycling in trees is necessary to satisfactorily interpret this particular historical Hg record.

Sampling design optimization for multivariate soil mapping

Much attention has been paid to sampling design optimization over the past decades. Many methods have been developed and applied, but only a few of these deal with simultaneous optimization of the sampling design for multiple soil variables. In this paper we present a method implemented as R-code that minimizes the average kriging variance (AKV) for multiple soil variables simultaneously. The method is illustrated with real soil data from an experimental field in central Czech Republic. The goal of the method is to minimize the sample size while keeping the AKV values of all tested soil variables below given thresholds. We defined and tested two different objective functions, critical AKV optimization and weighted sum of AKV optimization, both based on the AKV minimization with annealing algorithm. The crucial moment for such an optimization is defining the mutual spatial relationship between all soil variables with the Linear Model of Coregionalization and proper modelling of all (cross)variograms which are used in the optimization process. In addition, a separate optimization was made for each of the tested soil characteristics to evaluate a possible gain of the simultaneous approach. The results showed that the final design for multivariate sampling is “fully-optimal” for one soil variable — optimal number of observations and optimal structure of sampling pattern, and “sub-optimal” for the others, while no clear difference between the two optimization criteria was found. We can recommend using the method in situations where periodical soil surveys are planned and where multivariate soil characteristics are determined from the same soil samples at once.

Distribution and Speciation of Mercury in Mine Waste Dumps

Mine waste dumps of historic mercury mines represent environmental threat. In the central Czech Republic, Hg ores were mined at two sites for more than 150 years. Mine wastes collected from dumps near Hg mines were elevated in total Hg (up to 120 microg(-1)). Thermal-desorption method revealed that most of Hg (>80%) in studied waste material was present as cinnabar (HgS), that is relatively stable in soils and resistant to formation of highly toxic methyl-Hg. Nevertheless minor part (<14%) of total Hg was identified as mineral surface bound Hg, which might undergo methylation and thus represents potential long-term environmental risk.

Manganese Biogeochemistry in a Central Czech Republic Catchment

Mn biogeochemistry was studied from 1994 to 2003 in a small forested catchment in the central Czech Republic using the watershed mass balance approach together with measurements of internal stores and fluxes. Mn inputs in bulk deposition were relatively constant during a period of sharply decreasing acidic deposition, suggesting that the Mn source was terrestrial, and not from fossil fuel combustion. Mn inputs in bulk deposition and Mn supplied by weathering each averaged 13 mg m−2 year−1 (26 mg m−2 year−1 total input), whereas Mn export in streamwater and groundwater averaged 43 mg m−2 year−1. Thus an additional Mn source is needed to account for 17 mg m−2 year−1. Internal fluxes and pools of Mn were significantly greater than annual inputs and outputs. Throughfall Mn flux was 70 mg m−2 year−1, litterfall Mn flux was 103 mg m−2 year−1, and Mn net uptake by vegetation was 62 mg m−2 year−1. Large pools of labile or potentially labile Mn were present in biomass and surficial soil horizons. Small leakages from these large pools likely supply the additional Mn needed to close the watershed mass balance. This leakage may reflect an adjustment of the ecosystem to recent changes in atmospheric acidity.

Mineralogical controls on the distribution of trace elements in metasomatized peridotite enclaves from Planany, Czech Republic

AbstractSmall (m-scale) peridotite enclaves at Planany (central Czech Republic) are separated from their gneissic host rocks by a narrow (cm-scale) reaction rim comprising an inner, tremolite + phlogopite zone and an outer, essentially monomineralic phlogopite zone. Both retain an Mg# very similar to that of the peridotite (Mg# = 81), but relative to this reference frame, show large increases in LILE (K, Rb, Ba) and radionuclides (U, Th). On a smaller scale, however, there has been a mineralogically-controlled decoupling of various components, particularly among the HFSE and REE, the former favouring the phlogopite-rich outer layer of the reaction rim, the latter the amphibole-rich inner zone. Taken together, however, the reaction zones preserve key compositional features of their inferred protolith.

Aggression and commensalism in house mouse: a comparative study across Europe and the near east

Species specific differences of house mouse social behavior compared to its closest relatives (aboriginal species Mus macedonicus, Mus spicilegus, and Mus spretus) have recently been suggested. However, substantial variation of behavioral traits between mouse populations has been also evidenced. Agonistic behavior of laboratory-born house mice from five commensal populations (Mus musculus musculus: central Czech Republic, Mus musculus domesticus: Bulgaria, Greece, Turkey, and natural Mus m. musculus/domesticus hybrids from the Czech part of the hybrid zone) and five non-commensal populations of M. m. domesticus (C. Syria, E. Syria, Jordan, Iran, Libya) was studied. Dyadic interactions in a neutral cage were performed and the effects of sex and population on time spent by agonistic behavior evaluated. In all studied populations, the male-male interactions were more agonistic than the female-female ones. Male-male behavior gradually increased from the least agonistic population of M. m. musculus from Central Europe to the Near East populations of M. m. domesticus exhibiting the highest scores of agonistic behavior. Between-population differences were even stronger when female-female encounters were considered. While females of commensal populations belonging to both M. m. musculus and M. m. domesticus were tolerant of each other, those coming from non-commensal populations of M. m. domesticus were highly agonistic, reaching even the level of aggression between the females of some aboriginal mouse species. This phenomenon may be attributed to increased competition for food in non-commensal populations when compared to commensal ones supplied by superabundant resources. Social behavior of house mice, therefore, appears to be pliable rather than rigid and species specific. It can be changed rapidly according to ecological needs and such adaptability allows house mice to colonize various habitats. Aggr. Behav. 31:283–293, 2005. © 2005 Wiley-Liss, Inc.