Our paper reviews the current understanding of mercury in the environment of soil and sediment, including sampling, mobilization phases and analyzing methods. As a dangerous trace element, mercury has been shown to have several harmful effects on the environment. Mercury is released into the environment in a variety of chemical forms by both geogenic and human activities, with the majority of it coming from anthropogenic sources. It is affected by environmental conditions such as pH, redox potential, light and temperature-all of which determine its final chemical form-reactivity and toxicity. Methylmercury is considered one of the most poisonous forms found in nature. Considering the methodologies of the studies carried out we have found that the best technique for preserving methylmercury in soil and sediment samples is to freeze it immediately after collection. Organically rich soils are related to higher total mercury levels. Plants, such as Solanum nigrum (BR3) and Cynodon dactylon (BR2), can play an important role in mercury transport and accumulation. Solid-phase selenium causes faster demethylation and slower methylation of mercury. Methylmercury can increase by climate change and thawing; arctic permafrost is a potential source of Hg. Chemical vapor generation inductively coupled plasma mass spectrometry was used to develop a simple and quick method for measuring methylmercury; ultrasonic agitation and HNO3 were used for the process, the last of which proved to be the most efficient for selective extraction of methylmercury.

Vehicle collisions with animals pose serious issues in countries with well-developed highway networks. Both expanding wildlife populations and the development of urbanised areas reduce the potential contact distance between wildlife species and vehicles. Many recent studies have been conducted to better understand the factors that influence wildlife–vehicle collisions (WVCs) and provide mitigation methods. Most of these studies examined road density, traffic volume, seasonal fluctuations, etc. However, in analysing the distribution of WVC, few studies have considered a spatial and significant distance geostatistical analysis approach that includes how different land-use categories are associated with the distance to WVCs. Our study investigated the spatial distribution of agricultural land, meadows and pastures, forests, built-up areas, rivers, lakes, and ponds, to highlight the most dangerous sections of roadways where WVCs occur. We examined six potential ‘hot spot’ distances (5–10–25–50–100–200 m) to evaluate the role different landscape elements play in the occurrence of WVC. The near analysis tool showed that a distance of 10–25 m to different landscape elements provided the most sensitive results. Hot spots associated with agricultural land, forests, as well as meadows and pastures, peaked on roadways in close proximity (10 m), while hot spots associated with built-up areas, rivers, lakes, and ponds peaked on roadways farther (200 m) from these land-use types. We found that the order of habitat importance in WVC hot spots was agricultural land < forests < meadows and pastures < built-up areas < rivers < lakes and ponds. This methodological approach includes general hot-spot analysis as well as differentiated distance analysis which helps to better reveal the influence of landscape structure on WVCs.

Aim:Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW). Location:Global. Taxon:All extant mammal species. Methods:Range maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species). Results:Range maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use. Main conclusion:Expert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control.

We re view the cur rent en vi ron men tal pol lu tion by mer cury in the soils of Po land and Lith u a nia and in the sed i ments of the Bal tic Sea. Mer cury is doc u mented to have many neg a tive im pacts on the en vi ron ment as a toxic trace el e ment. In many dif - fer ent chem i cal forms, it is be ing re leased into the en vi ron ment by both geogenic and anthropogenic ac tiv i ties, with most be - ing re leased from anthropogenic sources. Methylmercury is con sid ered one of the most toxic forms found in the en vi ron ment. Mer cury levels in sed i ment and var i ous point sources in creased af ter World War II in the Bal tic Sea, which was used as a dumpsite. Pre vi ous stud ies show no tice able dif fer ences in to tal mer cury in the Bal tic Sea. In the Warta and Odra rivers in Po land, mer cury levels are also higher than the back ground value, though re cent find ings sug gest that river sed i - ments are not the main source of mer cury to ma rine sed i ments. Con cen tra tions in soils in Po land and Lith u a nia were be low the level of limit val ues (1 and 1.5 mg/kg-1 re spec tively), but Up per Silesia showed con cen tra tions (up to 4.01 mg center dot kg-1) above the limit val ues. Fur ther more, be tween 1992 and 2006, mer cury levels in Wroc3aw dropped dra mat i cally. The dom i - nant trees in the area can af fect mer cury ac cu mu la tion. No data were avail able for com par i son with the soils in Es to nia and Latvia.

We investigated the relationship between lunar illumination based on the percentage of the visible lunar disk (LDP) and the frequency of wildlife–vehicle collisions (WVCs) in Lithuania. We analyzed WVC frequency during ten 10% LDP intervals to more precisely reflect the relationship between LDP and WVC. The 10% LDP interval approach showed a significant trend of increasing WVC frequencies with an increasing LDP at night. We also examined the correlation between the daily numbers of WVCs and LDP for different months and seasons. The relationship seemed to be stronger at night and during the late autumn–winter months, particularly in December, suggesting the importance of lunar illumination on WVCs. There was a weak positive correlation between LDP and overall daily number of WVCs (rs = 0.091; p < 0.001) and between LDP and night WVCs (rs = 0.104; p < 0.001). We found significant positive correlations for winter (December–February) (rs = 0.118; p = 0.012) and autumn (August–November) (rs = 0.127; p = 0.007). Our study suggests that the LDP interval approach may provide more possibilities for the evaluation and quantification of WVCs and lunar light relationships than the traditional lunar phase approach.

Ungulates (mainly Cervidae and wild boar Sus scrofa) are considered among the most problematic wildlife suffering on roads and causing the largest material losses due to high densities of ungulate populations, spatial and temporal movement patterns, and body size of these animals. Roe deer–vehicle collision (RDVC) as the most usual cause of ungulate fatality on roads may be applied as an appropriate model for understanding ungulate-vehicle collision patterns in general. To better understand, manage, and mitigate RDVCs, a detailed knowledge of the temporal behavioral patterns of roe deer is essential. In order to determine the role roe deer behavior plays in RDVCs, we examine time-dependent patterns of RDVCs in Lithuania, a country with a relatively low human population density and less developed transport infrastructure compared with other European countries with relatively high human population density and more intensive road network. Our analysis includes 5556 RDVC records from 2013 to 2016 and examines both short-term and long-term periods to determine the interrelationship between roe deer behavior and vehicle collisions. Our results document the relationship between RDVCs and season of the year with the highest RDVCs peaks occurring in late spring (May, 817, 14.7% of RDVC) and late autumn (November, 626, 11.3%). The daily RDVC frequency is influenced by seasonal changes in sunrise, sunset, and timing of twilight and the impact of these environmental variables on vehicle operator behavior. Our findings are comparable with those reported elsewhere in Europe and suggest that roe deer temporal behavioral patterns influence RDVCs more than transport infrastructure.

Food storage (caching, hoarding), which is observed in many species of animals, increases food availability during times of food insecurity. Both species of beaver (Eurasian beaver, Castor fiber, and the North American beaver, C. canadensis) living at northern latitudes where food may be scarce during winter are larder‐hoarders, constructing a food cache of branches of woody species during autumn. We studied the food caching behavior of the Eurasian beaver in three northern European countries (Sweden, Norway, Lithuania) to provide additional insight into this important behavior. Thirty‐seven of forty‐seven (79%) active family groups had food caches by mid‐November and 41 of 47 (87%) had caches by December. Water depth of caches ranged from 1 to 2.3 m and depths at caches in Sweden were significantly deeper than in either Norway or Lithuania. Construction of caches began as early as late September (week 39/40) in Sweden and Lithuania and by mid‐October (week 42) in Norway. We observed plasticity in timing of cache initiation but the majority of active sites in all areas had food caches by the beginning of November (week 45). Declining air temperature and mean minimum temperatures of 0°C or below were associated with cache initiation. Caches in Lithuania were larger than in Sweden and Norway, which may be associated with colder winter temperatures. We did not find any relationship between family size or length of territory occupancy and cache size at our Norway sites where population demographics were available. Our results are generally consistent with other studies of food caching behavior in both species and suggest general similarities as well as behavioral plasticity in this important evolutionary strategy.

We studied beavers' dietary preferences and the role of several factors (such as plant species, size and anthropopression level) that affect the beavers' foraging in northern Poland. Woody plants along the river were measured and classified according to species in six 100 m-long transects that were characterized by a diversified human disturbance level. Ivlev's electivity index was used to present the beavers' preferences for various plant species and sizes, and the generalized linear model was used to assess the significance of studied factors in beavers' browsing choices. Most popular in the beavers' diets were willows (Salix), maples (Acer) and alder (Alnus), but only willows and maples were preferred. We noted a decrease in the beavers' foraging preference in parallel to an increase in the shoot diameter; plants with a diameter below 10 cm were preferred. All factors included in the generalized linear model (GLM) were significant in shaping the beavers' foraging choices. A negative correlation between the shoot diameter and the human disturbance level was found, but the species composition of the browsed woody plants was the same in each transect. Beavers' foraging preferences, as observed in our study, were similar to those described in the literature and confirmed the role of woody species and their diameters in shaping the beavers' diet. We also suggested the potential role of anthropopression in the shaping of the beavers' foraging behaviors.

The Modern Evolutionary Synthesis of the mid-twentieth century presented a unified approach to the understanding of evolutionary mechanisms by integrating studies of paleontology with those of modern genetics. In the past twenty years, the field of evolutionary developmental biology has not only added a third discipline to the synthesis, but has also provided surprising insights into the role of gene regulation in the evolution of animal body plans. Evolutionary developmental biology can also illustrate evolutionary principles in a comprehensive fashion, as it provides a means of visualizing gene expression in space and in time in a developing embryo. The College of General Studies at Boston University is finding ways of incorporating the central themes of evolutionary developmental biology into its core required undergraduate course on evolution, the history of the idea, and its mechanisms. The idea that alteration in gene expression during embryologic development is an important source of variation as well as a critical aspect of species stability not only informs students about the link between inheritance and selection, it also provides a map for illustrating how gene activity creates three-dimensional forms. It thus provides a concrete means of explaining anatomical homology, an historically important body of evidence for evolution and one most easily studied by beginning biology students. Since understanding of evolutionary principles is an essential basis for the study of modern biology, examination of the findings of evolutionary developmental biology should be a required part of any basic biology course that deals with evolution.

Preference of beavers for tree and shrub species during the autumn food caching period was investigated in western Massachusetts. Cafeteria-style feeding experiments designed to test differences in food selection for immediate consumption vs longer-term storage were conducted. Beavers removed 80 to 95.9% of all branches of deciduous species offered, while only 65% of the branches of the one evergreen species (Pinus strobus) offered were removed. Witch hazel (Hamamelis virginiana) was consistently cached more often than other species, especially in early autumn. The most abundant species available near the colony area, red maple (Acer rubrum), was removed at a high rate, but used for immediate consumption of construction in early autumn, and not stored at a high rate until November. The differential use of woody species is more evident in early autumn whereas all species, including pine, are stored later in the caching period.

At a newly occupied pond, beavers preferentially felled aspen smaller than 7.5 cm in diameter and selected against larger size classes. After one year of cutting, 10% of the aspen had been cut and 14% of the living aspen exhibited the juvenile growth form. A phenolic compound which may act as a deterrent to beavers was found in low concentrations in aspen bark, and there was no significant regression of relative concentration of this compound on tree diameter. At a pond which had been intermittently occupied by beavers for over 20 years, beavers selected against aspen smaller than 4.5 cm in diameter, and selected in favor of aspen larger than 19.5 cm in diameter. After more than 28 years of cutting at this site, 51% of the aspen had been cut and 49% of the living aspen were juvenileform. The phenolic compound was found in significantly higher concentrations in aspen bark than at the newly occupied site, and there was a significant negative regression of relative concentration on tree diameter. The results of this study show that responses to browsing by trees place constraints on the predictive value of standard energy-based optimal foraging models, and limitations on the use of such models. Future models should attempt to account for inducible responses of plants to damage and increases in concentrations of secondary metabolites through time.

Journal Article Population Density, Colony Composition, and Local Movements in Two Sierra Nevadan Beaver Populations Get access Peter E. Busher, Peter E. Busher Department of Biology, University of Nevada, Reno, NV 89557 Search for other works by this author on: Oxford Academic Google Scholar Randall J. Warner, Randall J. Warner Department of Biology, University of Nevada, Reno, NV 89557 Search for other works by this author on: Oxford Academic Google Scholar Stephen H. Jenkins Stephen H. Jenkins Department of Biology, University of Nevada, Reno, NV 89557 Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 64, Issue 2, 24 May 1983, Pages 314–318, https://doi.org/10.2307/1380566 Published: 24 May 1983 Article history Received: 05 April 1982 Accepted: 03 August 1982 Published: 24 May 1983