Daily emigrations of non-native age 0 and age 1 potamodromous (fluvial) rainbow trout Oncorhynchus mykiss and brown trout Salmo trutta were investigated in two Missouri River tributaries, USA over the period 1998–2002. The patterns of emigration for both age 0 and age 1 fish of both species were highly variable, sometimes showing bimodal (spring and fall) emigrations and other times less well defined patterns. Peak timing of age 0 emigration was also highly variable among years (up to 5 months) and more variable than the timing of age 1 emigrations (more than two months). Emigrations were preferentially associated with increasing photoperiod before June 22, with water temperatures from 7.5 to 12.5 °C, and often followed sudden increases in stream discharge. More emigrations were associated with the new moon phase as opposed to the full moon phase. In an analysis of models of emigration (2 rivers × 2 species × 2 ages/species × 31 model combinations for five categorical variables — year, temperature, discharge, moon phase, and photoperiod) using the information-theoretic approach, none of the models were especially effective at explaining emigrations; for the 16 models (i.e. the two with the lowest AIC per river, species and age), no corresponding multiple linear regression model explained more than 41 % of the emigration, and most other models explained considerably less. Results of this study suggest that emigrations of both brown and rainbow trout as part of their fluvial life histories are potentially influenced by a variety of environmental factors, and can be expected to show considerable variation yearly based on the complex, poorly defined genetic origins of the fish and the highly variable climatic conditions associated with the Missouri River Basin.

The anadromous Rutilus kutum Kamenskii, 1901 is the most important fish in north of Iran with the highest economic value. Ignoring the natural process of reproduction due artificial propagation, catching some migrating broodstocks from the sea (not from the estuaries) and mixing the produced fingerlings in culture ponds within restocking programs in the last 30 years have caused an uncertainty about homing success and population differentiation in the fish. A 13-landmark morphometric truss network system was used to investigate the hypothesis of homeward migration success and population differentiation, while the previous studies revealed low genetic variability among the fish populations. A total of 504 adult specimens were caught from four localities along the southern Caspian Sea in the reproductive period. Univariate analysis of variance showed significant differences among the four groups for 78 standardized morphometric measurements. In linear discriminant function analysis (DFA), the overall assignments of individuals into their original groups were 73.3 % and 80.3 % in males and females, respectively. The principal component analysis (PCA) and clustering analysis based on Euclidean square distances showed that the 504 examined specimens grouped into distinct areas. The results showed that each sampling site represents independent population which confirmed the success of homeward migration. The high grouping ranges suggests that almost all populations return to their birthplace river to breed, which results in high inbreeding. The results can be interesting for management and conservation programs of this valuable species in the Caspian Sea.

We studied the amphibian breeding migration into an old established (the beginning of the 1990s) pond and a new one (2007), using drift fences in 2008–2011. The two ponds were located at a distance of about 0.5 km from one another in a post-agricultural landscape in the Mazurian Lakeland, north-eastern Poland. We examined the community structure and migration rates of adults and juveniles. The amphibian breeding communities were similar in the two ponds in each year. The moor frog Rana arvalis was the most common species and comprised between 35 and 55 % of all adult amphibians migrating to both ponds. The new pond was colonized by adult amphibians in the first spring after its creation. In the second year, the amphibian migration rates doubled in the new pond and remained stable over the next two years. However, during the entire period of the study the old pond was a more attractive spawning site than the new pond, when measured by the number of migrating individuals of all recorded species. Despite some annual variation, there were no significant differences between the ponds in terms of the sex structure, mean body mass or migration timing of the predominant amphibian species. The most probable explanation for the observed differences in the rates of migration is breeding site fidelity.

The aim of our study was to identify the most important ecological factors influencing the breeding density of chukar partridges (Alectoris chukar) in Southeastern Bulgaria. Identified habitats were divided into two categories: 1) natural habitats with an extant population of the species, and 2) habitats in which it was absent. In each habitat, annual precipitation, lowest elevation in the habitat, Paliurus cover, grazing livestock per 100 ha, shrub height, shrub density, bedrock type, percentage of pastures, percentage of agriculture, percentage of wetlands, percentage of rocks, presence/absence of buildings, presence/absence of highways, plant species composition, plant layer coverage, and chukar breeding pairs were measured. We have found several habitat variables that probably affect the density of nesting chukar partridge. These are: 1) grazing intensity, 2) percentage of rock outcrops, 3) percentage of grasslands, 4) shrub cover, and 5) elevation. Grazing intensity and rock outcrop presence, together with the elevation gradient, influence the breeding pair distribution and abundance most significantly. Our study has confirmed only three types of habitats that the chukar currently prefers to nest in. Unknown factors probably changed the other sites in a way that they are no longer suitable for the species’ existence and reproduction.

Research on the diet of barn owls on some of the lesser Pityusic Islands (Formentera, s'Espalmador and s'Espartar) reveals a previously undescribed opportunistic trophic behaviour based on regular foraging in patches of territory separated by relatively broad sea channels. Individually, small islets with reduced human influence do not usually provide enough food for the barn owl. Consequently, the species expands its home range to include multiple islands or islets. This study is the first to document the regular crossing of broad sea channels (one of which exceeds 4.5 km) by barn owls in order to hunt. The islets provide the barn owls with prey otherwise considered as marginal (such as Oryctolagus cuniculus and Hydrobates pelagicus).

The timing of clutch initiation in migratory birds is determined by many factors and affects fitness. In polygynous species the date of egg laying may also be determined by mating status. In order to identify the habitat factors enabling Eurasian bittern females to breed early, a study was carried out on nine fishpond complexes in eastern Poland during 2003–2009. The habitat characteristics of the nesting sites, including fish stock type and the breeding success were recorded for 48 monogamous, 31 primary, 30 second and 12 third or fourth females. The analysis showed that early nesting females preferred a higher density of old reed stems and chose less attractive ponds with poorer food resources. Monogamous and primary females laid first eggs eight days earlier on average and had higher breeding success than the second, third and fourth females. The relationship between the fate of broods and the breeding success of neighbouring nests was found for second females. Our results suggest that Eurasian bittern females benefit from early nesting, provided they can find appropriate vegetation at the nesting site.

The aim of this work was to use standardized digital cartography of vegetation coverage to test whether or not the predicted range of habitat suitability for wild boar in Bulgaria coincides with the georeferenced/presence records of this species. The predicted range of habitat suitability based on potential biological resources in Bulgaria encompasses 13 land uses from the CORINE program, being “Broad-leaved forests” (23432 km²) the most representative. The total potential resources for wild boar correspond to 57.54 % of the country area. A high level of correlation (0.86) was found between inverse distance of wild boars presence and habitat suitability areas. A significant level of correlation (0.71, p < 0.0001) per Bulgarian region between area of habitat suitability category 2 (resources suitable for use as both food and shelter) and number of wild boar was also found.

Suitable wild boar habitat on borders appeared as the most relevant parameter for evaluating the risk of introduction of diseases by wild boar into the European Union from neighbouring countries. Despite being the longest (608 km), the Bulgaria-Romania border did not represent the most important corridor for wild boar since only 12.78 % of its surface is suitable habitat; the percentage of the importance of this border edges the passage of wild boar is 20.63 %. The Bulgaria-Macedonia (FYROM) border must be regarded as the most important passageway for wild boar (96.88 %), with 148 km of border and 12.34 % of its surface area of suitable habitat. Our findings could be highly useful for developing adequate strategies for wildlife management practices on large spatial scales, as well as for the control of wildlife and its habitats (territorial integration and spatial planning according to the casuistry of the zone), and relationships between wildlife and other human interests.

Bats occupy a variety of natural and artificial diurnal roosts. These environments offer several advantages for bats, among which we highlight the relative climatic stability, darkness, and protection from predators. The aim of this study was to identify and describe the use of tree hollows as natural diurnal roosts by Molossops temminckii, Molossus rufus, Artibeus planirostris and Sturnira lilium in southeastern Brazil. In the first one, we sought to describe the physical characteristics of shelters. In the second objective, we determined the number of individuals in the colonies and, we described and classified the posture adopted by bats within cavities. In the third objective, we seek to relate the physical characteristics of refuges with the foraging behavior and diet of bat species. Moreover, we also discussed the advantages and disadvantages that tree cavities may confer for bats, in the context of approximation of opportunistic predators. We found four colonies, one of each species, which roosted within tree trunk cavities. In general, the colonies were small, with less than 10 individuals of both sexes. Usually the molossids left the roost at dusk, while phyllostomids left later, around three hours after dusk. Individuals of the first three species were recaptured while foraging near the roosts. We believe (through observations) that the location in the landscape and the physical characteristics (dimensions of access to the cavities and height from the ground) of shelters used by bats, depend exclusively on the morphology, foraging behaviour and diet of each species of bat. Furthermore, this study contributes to an increase of knowledge about the natural history of Neotropical bats, which can provide relevant information for conservation.

Among populations of the Miniopterus bats of western Palaearctic, intraspecific variation has not been well documented. Herein we investigate sexual and age variation of these populations using two approaches — linear and geometric morphometrics. We analysed Moroccan (M. maghrebesnis), western and eastern European (M. schreibersii), Levantine (M. schreibersii), and east-Afghanistani (M. cf. fuliginosus) specimens; variation was compared between sexes of the particular specimen sets of three above mentioned Miniopterus spp. and between four age cohorts of M. schreibersii samples. The results showed in all examined population sets males to be generally larger in size than females, the exception being the east-European animals. Significatly the most divergent sexes were those from eastern Afghanistan, the Levant and eastern Europe. The differences found between sexes in as well as between examined population sets can be attributed to different life histories and/or to food competition. Weak correlations between patterns of sexual dimorphism and the newly proposed western Palaearctic classification of the Miniopterus bats suggest only a limited contribution of sexual variation to morphological variation in general. Certain aspects of age variaton were found in all examined morphological characters except the non-metric traits, which in turn indicates the importance of these traits for identification of the particular taxon across age categories.