Spring spawning migrations of paddlefish Polyodon spathula into the River Missouri above Fort Peck Reservoir, Montana were investigated with radio-telemetry during 2006–2009. Selected migration characteristics (total movement, rate of movement, maximum upriver ascent, duration of the migration, upriver residence time and spawning periodicity) were compared between sexes and among years. Paddlefish exhibited sexual dimorphisms in selected measures of migratory behavior. Females typically moved at a faster rate (mean, 13.4 km/ day for females versus 10.1 km/day for males) and remained in the river a shorter time (mean, 40 days) than did males (mean, 45 days). Females and males exhibited similar total movements, upriver residence times and mean maximum ascents. Spawning periodicity was shorter for males (mean, 1.5 years) than females (mean, 2.3 years). Total movement, movement rate, mean duration of the spawning migration and upriver residence time of both sexes differed among years. Results from this study indicate that certain analyses of paddlefish migrations and migratory behavior should be undertaken separately for female and male fish.

Knowledge of food resource partitioning between sympatric fish species is critical for understanding the fish communities functioning. Four sympatric fish species (Salmo trutta, Pseudochondrostoma duriense, Squalius carolitertii and Barbus bocagei) were captured in August 2010 in the River Tormes (Ávila, Central Spain) in order to study food resource partitioning between fish species such us as a possible mechanism enabling their coexistence, using a fuzzy principal component analysis (FPCA). Diet comparison among species shows that detritus are present in P. duriense, B. bocagei and S. carolitertii, although in different occurrence, showing that these species present typically omnivorous feeding habits. Regarding prevalent food, in all species, benthic prey constituted the most important prey in abundance terms, and terrestrial invertebrates were only consumed by S. trutta, S. carolitertii and P. duriense. High overlap values (Schoener's index from 0.8 up to 1) were found, but it may not indicate competition, since species can adopt different strategies to overcome competence. Thus, prey traits analyses suggest that differences in macrohabitat use, drift behaviour of prey and prey size are important adaptive features that may reduce the inter-specific competition in the fish community and permit the food partitioning that allows coexistence.

Several series of available environmental (land use/land cover, agriculture, soil, climate) variables are used in exploratory models to test their use for successful prediction of red-legged partridge (Alectoris rufa L.) abundance in spring. A Geographic Information System and stepwise multiple regression analysis are used to show and predict distribution of this population parameter in an agricultural region of southern France. High spring abundance was observed to be distributed mainly in the central and north-western part of the study area. Two partial models, land use/land cover and agriculture, and a complete model with land use and temperature variables are the most significant and more accurate than any others. The complete model is the best model (lowest Akaike Information Criterion and highest Akaike weight). The potential abundance obtained from this best model shows communes with high Kilometric Abundance Indices (KAI), mainly located in the northwestern part of the region. Partridge abundance was unevenly or irregularly distributed across the study area, which is typical of wildlife species inhabiting complex and changing landscapes limited by various sources of human pressure, such as agriculture, urbanization and game management. A game tool is provided using potential spring abundance to plan the harvest quotas two months before opening the hunting season.

Predators activate a search image process for the most frequent prey type as a result of repeated chance encounters with that prey. In addition, selective attention to a limited subset of prey visual features should increase the precision with which the prey is discriminated from the background. In our experiment, we investigated the effects of multiple backgrounds on prey detection by captive American kestrels (Falco sparverius). We predicted that the background itself can serve to cue attention towards the prey type and that a most recent experience provided predictive information. As expected, we observed the effects of search image formation where the background was informative (familiar substrate). Nevertheless, search image effects disappeared with extended practice and kestrels rapidly increased the use of unfamiliar background where prey were completely non-cryptic. Our data suggest that short-term changes in prey detection of a predator cue with the background upon which this prey is found. We discussed the results in the light of related studies on neophobia, visual acuity and achromatic and chromatic contrasts.

Nest boxes for breeding tawny owls (Strix aluco) were located in a mixed oak-hornbeam-beech (Quercus-Carpinus-Fagus) forest in the Duna-Ipoly National Park, 30 km northwest of Budapest, Hungary during the period 1992–2010. The 550 m altitude range (120–680 m) of the study area was divided into low and high elevations: < 400 m, and > 400 m, each containing 88 nest-boxes. We marked 77 males in their first breeding year and evaluated the lifetime territory occupation and reproductive performance for individuals which reached five, six, seven, eight or nine years old. The fledgling production of tawny owl males increased in their first, second and third years, reached a high level in years four and five, but declined once they were six years old. The relative low reproductive performance in the early and late years of the males' lives may be attributed to the fact that the majority of males were unable to occupy high quality territories, and the rate at which individuals skipped breeding was high. We suggest that both the reduced ability to acquire high quality territories and declining fledging production in late years of males reflect senescence patterns in tawny owls.

The winter diet of the great tit (Parus major) was examined in mixed and deciduous forest in central Slovakia during three winters. Using a faecal samples analysis, in 105 sampled roosting individuals (in nest-boxes) at least 37 taxa of invertebrates were found. Apart from the invertebrates, plant material was identified in dissected birds' droppings as well. There were no significant differences in the winter food composition between sexes. Generally, plant material was the most frequent and the most dominant winter food. This component was followed by moths, beetles and dipterans. While comparing the relative volume between two distinct habitats, the most significant difference was found in Lepidoptera adults and plant material. Birds from mixed forest foraged less on Lepidoptera adults in contrast to individuals from deciduous forest. This could be compensated by bigger consumption of seeds and buds there. Regarding seasonal changes, within five winter months (from November to March), the relative volume and frequency of some invertebrate groups (Heteroptera, Homoptera and Lepidoptera) significantly increased with the temperature but no correlations were found with other weather characteristics. Invertebrates exhibited the opposite seasonal pattern compared to the plant material.

Wild boar is an autochthonous animal species of the Czech Republic that has significantly increased its population density in recent years. There are concerns that there is an associated negative impact upon agricultural crop production however, objective methods for sustainable management of wild boar, especially for estimation of its population density and intensity of regulation are still lacking. Wild boar differs markedly from the other free-living ungulates in its spatial activity and food selection, which limits applicability of the experiences and methods used for other species. Two methods of wild boar population censusing in a forest environment were tested in this study.

The density of wild boar was evaluated in an area of 2256 ha, circumscribed by both natural and man-made barriers that restrict wild boar migration. Wild boar abundance was estimated using traditional snow-track counting and photo trapping data analysis. Both field methods were used in the winter season 2009-2010. Wild boar abundance as assessed by snow-track counting was 6.3 ind./km² and by phototrapping 6.8 ind./km². The results have revealed that if correctly performed, both of the tested methods are applicable to estimate wild boar abundance. Photo trapping seems to be more accurate; it requires special equipment and is time-consuming, however, it provides additional information on the structure of the population and requires less experience to undertake. Combination of several methods is advisable.

The allometry between baculum size, body size and body condition was studied in the polecat (Mustela putorius). The aim of this study was to investigate whether penis size is dependent on body size. We also calculated the correlation between the size of the baculum and body condition. Our research was based on 107 bacula and skulls from a museum in Slovakia. Individual traits describing the sizes of the body, skull and baculum were moderately to strongly correlated (r between 0.16 and 0.72). Condition was expressed as residuals from a regression analysis of body mass on structural body size. The size of the baculum was correlated with other measurements of body size and with body mass. Analysis revealed that the strongest positive correlation with condition of males was with the size of the baculum. Because the baculum varies between individuals and grows throughout life, the relationship between its size and condition confirms that the baculum may be a suitable indicator of male quality.

The striped hyaena Hyaena hyaena (Linnaeus, 1758) is globally categorised as “Near Threatened” and is nearly extinct in the Caucasus. In Armenia, the last published record dates back to 1925 and the last trustworthy sighting was in the late 1940s. Here, a dead hyaena is described which was found in 2010 near the Nrnadzor village in the extreme south of Armenia. Its skull was investigated, age was estimated by several methods (cementum layers, tooth eruption, fusion of cranial sutures, pulp cavity closure and tooth wear) and sex was determined from the sagittal, occipital and nuchal crests and by genotyping of skin DNA. The specimen was found out to be a female aged ca. 17–18 months. As this is the age of disperal and females play a pivotal role in the social life of this carnivore, the possibilities for recolonization and establishment of hyaena population in the Meghri district of southern Armenia are discussed. This area holds sufficient prey base and suitable arid landscapes for survival of this species. The recent record of another individual's fresh tracks on sand near Nrnadzor supports this hypothesis. Usability of different techniques of sex determination and age estimation in the striped hyaena is considered.

Mammals have the ability to identify particular conspecifics and in doing so use this information to discriminate between them, and respond in a manner that increases their survival and fitness. This narrative focuses on the behavioral challenges that voles face when they have to make decisions about mate choice, same-sex competition, odor communication, and sperm allocation. The narrative points out the different decisions that voles may make when they encounter the social information contained in the scent marks and over-marks of different conspecifics. The narrative demonstrates that the choices made by voles, and their resulting behaviors, may depend on several factors including the vole's own condition, age, and sex and those of nearby same- and opposite-sex conspecifics. The results of these studies are ecologically relevant as they reflect situations and challenges faced by free-living voles. The range of situations that voles find themselves and the decisions voles make when they encounter a potential mate or competitor become the backdrop of the narrative. Concentrating on the responses of a single model species was intentional. This approach may allow specific comparisons with other terrestrial mammals, facing similar behavioral and ecological challenges.

Adaptive immunity is commonly viewed as a unique vertebrate feature. A misleading view on vertebrate longevity compared to non-vertebrate animals together with oversimplification of ‘invertebrate’ phylogeny sometimes serves for justifying the limitation of adaptive immunity exclusively to vertebrates. However, here we emphasise that the borderline for differentiation between ‘innate’ and ‘adaptive’ immunity may be fuzzy and artificial. In each taxon, the feature of bearing a particular immunological mechanism should reflect its costs and benefits in a given ecological context. Hence, in invertebrates with a long lifespan some kind of acquired immunity could be expected. Indeed, several recent studies support this view. We therefore stress that the definition of ‘adaptivity’ of immune response should reflect the system function instead of a certain molecular mechanism adopted. If these altered criteria are considered then several pieces of recent evidence indicate that the adaptive immunity in animals might have arisen several times independently and in very different forms.