We assessed habitat selection patterns of the European bison (Bison bonasus) reintroduced to the Bieszczady Mountains (the Eastern Carpathians, Poland) using presence data and Ecological Niche Factor Analysis. During the growing season, bison selected habitats at higher elevations close to natural grasslands, coniferous forest, and stands with broken canopy, while in winter — lower elevations, close to agricultural areas and alder or pine stands. In both seasons, bison avoided busy roads. The use of low-elevation valleys in winter can be a trade-off between the access to good habitats with milder climate, and the risk associated with close proximity to people. Relative tolerance to proximity to infrastructure indicates that good quality habitats in its vicinity can be considered suitable for further expansion of the species' range. Optimal sites for bison introductions in the Carpathians should include areas at lower elevations, providing winter refuges, and allow unrestricted access to summer habitats at higher elevations.

Intensive forest management and landscape degradation are threats to amphibian populations. We modelled and compared the extinction and colonization dynamics of the great crested newt in four different spatial contexts that describe landscape change from past to present and future forest landscapes in eastern Finland. In future landscape scenarios, we explored the effects of two forest use intensities with different logging rotation times. The introduction of fish into breeding ponds has been the main cause of local extinctions of the great crested newt. In the future, intensifying land-use and shorter logging rotation will decrease the connectivity between ponds the most. In conservation planning, more attention should be paid to the spatial arrangement of habitat patches, especially if the intensity of human impact will increase. Conservation effort must be targeted towards securing source ponds in the core area and towards enhancing connectivity.

Chironomids have been widely used as indicators of trophic conditions of lakes due to their species-specific environmental requirements. In order to understand resilience and deterioration of aquatic ecosystems due to increases and/or decreases in external loading, recent chironomid community and water chemistry data of seven southern Finnish lakes with varying anthropogenic pressures and bathymetric properties were compared with similar data from the 1960s. Altogether 64 taxa were found. At present, the most numerous taxa are Procladius spp., Chironomus f.l. plumosus, Chironomus f.l. salinarius, Stictochironomus f.l. psammophilus, Benthalia spp., Tanytarsus spp. and Cladotanytarsus. In four lakes, current abundances of chironomid larvae are clearly lower, and in two lakes abundances are higher than during the 1960s. In two shallow, previously highly eutrophic lakes, the chironomid community composition revealed an improvement in the trophic status, while in three deep, previously moderately oligotrophic lakes, a slight deterioration was found. The most dramatic increase in chironomid density and diversity was found in a lake which was most heavily polluted in 1960s. In deep lakes, a slow gradual eutrophication seemed to be responsible for the observed replacement of the previous oligotrophic communities, dominated by Monodiamesa bathyphila, Stictochironomus spp., Polypedilum f.l. breviantennatum and Heterotanytarsus apicalis by eutrophic taxa such as Chironomus f.l. salinarius, Chironomus f.l. plumosus, Einfeldia spp., Sergentia coracina and Microtendipes spp. Among the key factors responsible for changes were dissolved oxygen concentration, food availability, sediment quality, and in one lake, toxic effluents from industry.

We investigated interbreeding and admixture in Tetrix subulata grasshoppers from two maternal-origin populations that differed in life-history and dispersal traits. We compared reproductive output of females that had been experimentally mated with males from the same or from a different population. Interbreeding affected clutch size and number of clutches: in one population, females in the admixed treatment produced smaller clutches; in the other population, females in the admixed treatment produced more clutches. Behavioral observations indicated that individuals can discriminate scents emitted by individuals from different populations, so that females might adjust reproductive allocation depending on male origin. However, hatchability of eggs and survival of nymphs were not affected by the mating treatment. Admixture affected the production of viable offspring in the F2 generation, but the effect was opposite in the two populations of maternal origin. Results suggested that responses to interbreeding and admixture can differ between populations within a species.

White-tailed deer were introduced to Finland in 1934 from Minnesota, North America. The population has expanded and is now an important wildlife species, managed through hunting. We determined the age of 451 individuals harvested in the 2012 hunting season. Hunters measured their body mass after slaughter and we measured the dimensions of the lower jaw (in both sexes) as well as skull dimensions and antler scores (in males). The sample indicated a deficit of older males in the population. Females seem to gain their size at the age of two while males continue to increase their body size and that of skeletal traits until the age of four. The size traits measured were similar to those in the North American studies. Based on population growth patterns and introduction history, the white-tailed deer population is performing well in Finland but the potentially skewed sex-specific age distribution warrants further attention.

Small rodents living in forests use various spaces on trees for arboreal activities such as daily rest, hibernation, foraging, sheltering, roosting, and nesting. To investigate the differences in arboreal activity between two sympatric cavity-nesting rodents, Glirulus japonicus and Apodemus argenteus, we compared the frequencies of nest box use by these species at three different heights, and surveyed tree cavities. We observed that G. japonicus used nest boxes mounted at a relatively greater height most frequently, whereas A. argenteus used boxes placed at lower heights. Glirulus japonicus used all nest boxes for resting, while A. argenteus used most nest boxes for food hoarding. The tree cavities that were used by G. japonicus were located significantly higher than those used by A. argenteus. In a multinomial logistic regression analysis, height at which a cavity was located was identified as factor affecting frequency of cavity use.

Cage-trapping is one of the control methods frequently used by hunters to remove red foxes (Vulpes vulpes) in Spain, although its low efficiency and selectivity have been frequently reported. We tested the effect of the combinations of two bait types (live/ dead) and two scent attractants (fox urine/valerian extract) in order to improve the efficiency and selectivity of cage traps in central Spain. The combination of live bait and fox urine increased the efficiency of cage traps to capture red foxes in comparison with live bait alone. None of the experimental treatments led to a significant reduction in the capture rate of non-target species, selectivity levels were always low (0%–21%) and non-target species were captured. In view of that, the burden of releasing captured non-target animals depends ultimately on the trapper. For this reason, the use of cage traps is still questionable for managing foxes in Spain.

The aim of the present study was to investigate the macroparasite fauna of Pallas's squirrel, Callosciurus erythraeus, native to SE Asia, recently introduced to Italy and co-occurring with the native Eurasian red squirrel Sciurus vulgaris. A total of 161 Pallas's squirrels harboured a poor macroparasite fauna, characterized by two main ectoparasite species, the flea Ceratophyllus (M.) sciurorum sciurorum (prevalence 50%, mean intensity 1.0 ± 0.1) and the tick Ixodes ricinus (prevalence 47%, mean intensity 3.0 ± 0.7), and a few helminths (Rodentoxyuris sciuri, Trichuris muris, Strongyloides callosciureus) all with prevalence below 10%. All parasites, except S. callosciureus, are native to Europe and were acquired in the invaded range. The loss of native parasites might have contributed to their successful invasion. The acquisition of local parasites C. sciurorum and Trichuris sciuri, and the introduction of the Asiatic nematode S. callosciureus may lead to spill-back and spill-over processes towards red squirrels.

Many vertebrates have been shown to sense magnetic fields and align, in certain situations, their body axis along magnetic field lines. In an attempt to replicate earlier studies on magnetic alignment of chick embryos we incubated White Leghorn chicken eggs for three days and analyzed the embryo alignment axis in relation to topographic north and magnetic north, which we manipulated between trials. Overall the embryos did not follow the magnetic field alignments, however, they showed a strong clustering response to an unidentified non-magnetic factor. Reanalysis of a previously published dataset also revealed a significant topographic orientation towards the same general direction. However, further studies at different global locations are needed to solve these puzzling findings from two independent studies concerning very consistent embryo axis alignment of early chick embryos. Our study emphasizes the importance of experimental designs that allow clear decoupling of topographic effects from magnetic effects.

Color aberrations in birds are well documented, but frequently their terminology is misinterpreted. We report a record of color aberration in an adult ruddy ground dove Columbina talpacoti in Rio de Janeiro State, observed foraging with other conspecifics with normal pattern coloration. The color aberration was similar to a previous record of this species from the Rio de Janeiro municipality, but differed substantially from a third anomalous-colored specimen recorded in Venezuela. We suggest that the two Brazilian reports are cases of a non-phaeomelanin schizochroism based on the absence of the reddish-brown colors despite the presence of black and grey colors in feathers. We highlight the importance of using the right terminology for a better understanding of the frequencies of each color aberration type.