Phenotypic plasticity is defined as the ability of an organism to produce different phenotypes in response to changes in internal or external environmental conditions. Experimental modification of animal diets has been widely used to study phenotypic plasticity in physiological and life-history traits. Here we compared the data from a previous experiment, conducted in a harvestman species, that was aimed to evaluate the effect of diet quality on maintenance costs (standard metabolic rate), growth rate, internal organ size (visceral mass) and fecundity (clutch mass and egg number), with new data obtained from field (mark—recapture) specimens. We assumed that of the two experimental diets tested before, animals in the field would probably consume the one of intermediate quality (i.e. have a generalist omnivorous diet), and then, we predicted that field animals should exhibit intermediate values for both physiological and life-history traits. We found that field animals and animals consuming a high quality diet showed a greater growth rate than animals consuming a poor quality diet. In addition, animals consuming a high quality diet showed a larger clutch mass than both field animals and animals consuming a poor quality diet, which, in turn, was related to higher maintenance costs. Our results illustrate how animals adopt different life history strategies according to the quality of the diet that is available, which is correlated with phenotypic adjustments at the anatomical and physiological levels.

Finnish populations of the capercaillie Tetrao urogallus, black grouse Lyrurus tetrix and hazel grouse Tetrastes bonasia have been fluctuating in synchronous cycles. Mechanisms behind these fluctuations are not well known. Parasites may regulate their host population under certain conditions. The Finnish grouse harbour several species of intestinal parasites which may affect the populations. We studied the possibility of parasitic regulation in Finnish forest grouse using intestinal samples from hunted grouse collected in 1995–2000 and annual counts of grouse densities. We found that abundance and prevalence of the nematode Ascaridia compar affected negatively the grouse-community growth rate (all three species combined) and annual survival of grouse. In years of grouse density decline, the prevalence and abundance of A. compar was considerably higher than in other years. On the species level, this dynamic was most clearly seen in the capercaillie. The findings suggest the possibility of parasitic regulation by A. compar in the Finnish forest grouse community.

Łódź, one of the largest cities in Poland, is characterized by the presence of a large number of artificial and natural waterbodies. It, therefore, offers a great opportunity to study ways in which urbanisation affects cladoceran fauna associated with urban areas. We hypothesize that size of the waterbody is more important for the diversity and composition of cladocerans in urban ponds than direct effects of urbanisation. To test this assumption we analysed 21 ponds of different size and location along the urbanisation gradient. Redundancy analysis (RDA) based on 17 environmental factors and urbanisation parameters showed that distance from the city centre, number of plant species and pH were the most important factors shaping cladoceran fauna in urban ponds of Łódź. Non-metric multidimensional scaling (NMDS) based on the Bray-Curtis formula demonstrated that pond size (depth and surface area) was reversely related to the level of urbanisation, i.e., larger and deeper waterbodies were generally found in the outer city zone. The effect of urbanisation, resulting in a lower number of species and lower abundance in ponds located in the central part of the city, was indirect and resulted from the lower number of large ponds in this zone.

The importance of artificial underground habitats for biodiversity is becoming more and more apparent. Abandoned railway tunnels are artificial, underground habitats of considerable biodiversity, including several species of conservation concern. We surveyed 16 abandoned railway tunnels in 2014 in Romania for the following faunal groups: amphibians, terrestrial isopods, and spiders. Amphibians occurred primarily in flooded tunnels, isopods were present in moist tunnels with woody debris, while spiders were widespread and exhibited the greatest diversity in railway tunnels. Some species of amphibians breed in tunnels. The greatest diversity was observed in the entrance zones of tunnels; because railway tunnels are generally isolated from the surrounding rock, they can be colonized only from the entrances. In areas lacking natural subterranean cavities and habitats, railway tunnels are important habitats for many species, including troglophilic spiders and soil-dwelling isopods.

We analysed the diet composition of a recently recognized species, the African golden wolf (Canis anthus), in the Tlemcen Hunting Reserve in Algeria by means of scat analysis. A total of 246 scat samples were collected from the study area. Prey items found in the faeces were assigned to species or higher-ranked taxa using identification guides and our collection of hair samples from the reserve. We were able to identify 34 food items including wild and domestic animals, fruits, leaves, soil and organic waste. Animal remains represented 84.8% of the biomass consumed by the African golden wolf, while plant remains constituted 15.2%. Prey species richness was the highest in summer with 23 different food items and the lowest in autumn with 17 items. Wild boar was the most important prey in the species' food spectrum within the reserve. Our results show the opportunistic resource use by the African golden wolf, with seasonal variation and a propensity for large-sized prey, including considerable amounts of livestock carcasses (24% of the total biomass), which underlines the importance of an effective wildlife management.

The lake minnow Eupallasella percnurus is distributed throughout a vast area that includes most of Europe and northern Asia and displays a wide range of morphological variation, which resulted in five distinguished subspecies. There are no previous conclusive morphometric analyses of samples from different parts of the distribution area. This paper presents results of multidimensional analyses of morphometric characters of 19 widely scattered populations of the species. The results of the analyses show considerable inter-population differences. Morphometric evidence suggests that three morphologically different groups exist within the studied species. The population from the Volga river basin represents a distinct species tentatively called the ‘Volga lake minnow’. The populations from Poland; central, northern and northeastern Russia; and northern Kazakhstan form a group closely related to the nominative subspecies E. percnurus percnurus, whereas populations from southeastern Russia (including Sakhalin) and Hokkaido probably form a separate subspecies.

Biological invasions are considered one of the main causes of the current global biodiversity crisis. Many ungulate species have been introduced worldwide, mainly as game animals or e.g. as an attraction in suburban parks. We compiled the available information on distribution, abundance and ecology of the aoudad Ammotragus lervia outside its native range. We showed that the aoudad has established a number of populations in many countries outside its natural range. Alien nuclei have been recorded in at least 10 countries in Europe, Africa and America but it may be an underestimation. Establishment success differs geographically. North American and Spanish populations are large and still expanding, whereas others are small. This difference might be related to a large propagule pressure, but we suggest it might be due to multiple introduction events or better niche suitability. Information on potential impacts of alien populations on natural systems, human activities and disease spread is still scarce. Despite that, the aoudad is already known to be a carrier of parasites, and therefore it has been suggested that further range expansion of the aoudad may affect populations of native ungulates. Alien populations of the aoudad are controlled mainly by hunting, but as it targets mainly weak animals this method may actually improve reproductive success and increase invasive potential. Since prevention, early detection and eradication of small/isolated populations of invasive species are highly recommended, early and selective culling should be carried out to reduce population increase of this alien ungulate.