The feeding ecology of the golden jackal ( Canis aureus L., 1758) and its interspecific trophic relationship with the sympatric red fox (Vulpes vulpes (L., 1758)) was investigated in an area of recent range expansion of the golden jackal in Hungary, central Europe. Diet composition was determined by scat analysis (over 4 years: jackal 814 scats; fox 894 scats). Compared with jackals, foxes consumed more small mammals (mean biomass consumed: jackal 77%; fox 68%) and to a lesser extent plant matter (6% and 18%, respectively). The importance of other prey, such as wild boar ( Sus scrofa L., 1758), cervids, brown hare ( Lepus europaeus Pallas, 1778), birds, reptiles, fish, invertebrates, and domestic animals, was minimal. Both mesocarnivores consumed primarily small animals (<50 g: 92% and 87%, respectively); this implies a typical searching and solitary hunting strategy. The trophic niche breadth of both species was very narrow and the fox proved to be more of a generalist. The food overlap index between the two canids was high (mean, 73%) and varied with the decreasing availability and consumption of small mammals. Based on prey remains found in scats, small-mammal specialization over a 2-year period and seasonal predation upon wild boar piglets (mainly by the jackal), seasonal fruit eating (mainly by the fox), and scavenging on wild or domestic ungulates (both predators) were found.

In the first continent-wide study of the golden jackal (Canis aureus), we characterised its population genetic structure and attempted to identify the origin of European populations. This provided a unique insight into genetic characteristics of a native carnivore population with rapid large-scale expansion. We analysed 15 microsatellite markers and a 406 base-pair fragment of the mitochondrial control region. Bayesian-based and principal components methods were applied to evaluate whether the geographical grouping of samples corresponded with genetic groups. Our analysis revealed low levels of genetic diversity, reflecting the unique history of the golden jackal among Europe’s native carnivores. The results suggest ongoing gene flow between south-eastern Europe and the Caucasus, with both contributing to the Baltic population, which appeared only recently. The population from the Peloponnese Peninsula in southern Greece forms a common genetic cluster with samples from south-eastern Europe (ΔK approach in STRUCTURE, Principal Components Analysis [PCA]), although the results based on BAPS and the estimated likelihood in STRUCTURE indicate that Peloponnesian jackals may represent a distinct population. Moreover, analyses of population structure also suggest either genetic distinctiveness of the island population from Samos near the coast of Asia Minor (BAPS, most STRUCTURE, PCA), or possibly its connection with the Caucasus population (one analysis in STRUCTURE). We speculate from our results that ancient Mediterranean jackal populations have persisted to the present day, and have merged with jackals colonising from Asia. These data also suggest that new populations of the golden jackal may be founded by long-distance dispersal, and thus should not be treated as an invasive alien species, i.e. an organism that is “non-native to an ecosystem, and which may cause economic or environmental harm or adversely affect human health”. These insights into the genetic structure and ancestry of Baltic jackals have important implications for management and conservation of jackals in Europe. The golden jackal is listed as an Annex V species in the EU Habitats Directive and as such, considering also the results presented here, should be legally protected in all EU member states.

Eurasian otter populations strongly declined and partially disappeared due to global and local causes (habitat destruction, water pollution, human persecution) in parts of their continental range. Conservation strategies, based on reintroduction projects or restoration of dispersal corridors, should rely on sound knowledge of the historical or recent consequences of population genetic structuring. Here we present the results of a survey performed on 616 samples, collected from 19 European countries, genotyped at the mtDNA control-region and 11 autosomal microsatellites. The mtDNA variability was low (nucleotide diversity = 0.0014; average number of pairwise differences = 2.25), suggesting that extant otter mtDNA lineages originated recently. A star-shaped mtDNA network did not allow outlining any phylogeographic inference. Microsatellites were only moderately variable (H o = 0.50; H e = 0.58, on average across populations), the average allele number was low (observed A o = 4.9, range 2.5-6.8; effective A e = 2.8; range 1.6-3.7), suggesting small historical effective population size. Extant otters likely originated from the expansion of a single refugial population. Bayesian clustering and landscape genetic analyses however indicate that local populations are genetically differentiated, perhaps as consequence of post-glacial demographic fluctuations and recent isolation. These results delineate a framework that should be used for implementing conservation programs in Europe, particularly if they are based on the reintroduction of wild or captive-reproduced otters.

The feeding habits of feral domestic cats Felis catus (n=264), wild cats Felis silvestris (n=22) and their hybrids (n=30) were investigated in Hungary. Cat groups were identified taxonomically by morphological and molecular methods. Diet components were identified in stomach contents and faeces collected from the recta. In each cat group, abundant small mammals were dominant in the diet (relative frequency of occurrence: feral domestic cat, 61–82%, depending on regions; wild cat, 70%; hybrid, 59%). Birds were the second most important quarry (2–7%, 16% and 20%, respectively in the three cat groups), while the contribution of hares (1–2%, 5% and 3%, respectively) and other taxa was not significant. Every cat group preyed on small‐sized animals (<50 g; 89–96%, 80% and 80%, respectively), terrestrial (91–98%, 84% and 86%, respectively) and wild (71–73%, 87% and 77%, respectively) prey. Standardized trophic niche breadth was typically very narrow (BA=0.07–0.16, 0.13 and 0.17, respectively). Feral domestic cats occasionally consumed household food (2–7%) and domestic animals (4–8%). This could mean that feral domestic cats have an advantage over wild cats that are food specialists. The trophic niche overlap between cat groups was high (77–88%). Food composition and feeding habits, (weight, zonation and environmental association of consumed prey) of feral domestic cats, however, was different compared to wild cats, which indicated the possibility of partial resource partitioning. The values for hybrids were between the two groups. As well as the stable presence of feral domestic cats (mean population density, D=1.34 individuals/1000 ha) based on field live‐trapping, hybrids are also present (D=0.10), leading to continuous hybridization. This can threaten the population of wild cats, which are present at a low density (D=0.17).

In this study the predation and ®sh prey selection of otters Lutra lutra L. living by eutrophic ®sh ponds on agricultural land and in a protected area of temperate climate in Hungary were investigated. The correlations between ®sh in the diet of the otters (by spraint analysis involved 1942 and 1280 samples for the two habitats) and the ®sh stock available (by harvest and sample ®shing) were generally close. Prey selection was signi®cantly related to selected species of a particular size range (P < 0.01). The preference calculations were performed with Ivlev's index of preference (E i , minimum 71, maximum +1). Regardless of species, the otters avoided (E i = 70.51) ®sh heavier than 1000 g, with a preference for individuals weighing between 500 and 1000 g (E i = 0.79). No substantial or clear preference was observed in the weight range below 500 g (E i = 70.02±0.38). The preference for ®sh in accordance with their characteristic sites of occurrence within the body of water was also signi®cant (P < 0.01). They avoided ®sh living primarily in open water (E i = 70.64) and to a lesser degree those occurring near the pond bed (E i = 70.22). They favoured ®sh inhabiting the area with a covering of aquatic plants (E i = 0.46), and showed a preference to a lesser degree for ®sh living in the shallow littoral regions (E i = 0.14). With the cessation of ®sh farming and the effect of the drastic changes which occurred in the vegetation, the otters fed substantially on the stock of alternative sources of prey such as amphibians and water insects as well as terrestrial animals, and at such times, depending on season, ®sh became a secondary source of prey.

Although the phylogeography of European mammals has been extensively investigated since the 1990s, many studies were limited in terms of sampling distribution, the number of molecular markers used and the analytical techniques employed, frequently leading to incomplete postglacial recolonisation scenarios. The broad-scale genetic structure of the European badger (Meles meles) is of interest as it may result from historic restriction to glacial refugia and/or recent anthropogenic impact. However, previous studies were based mostly on samples from western Europe, making it difficult to draw robust conclusions about the location of refugia, patterns of postglacial expansion and recent demography. In the present study, continent-wide sampling and analyses with multiple markers provided evidence for two glacial refugia (Iberia and southeast Europe) that contributed to the genetic variation observed in badgers in Europe today. Approximate Bayesian computation provided support for a colonisation of Scandinavia from both Iberian and southeastern refugia. In the whole of Europe, we observed a decline in genetic diversity with increasing latitude, suggesting that the reduced diversity in the peripheral populations resulted from a postglacial expansion processes. Although MSVAR v.1.3 also provided evidence for recent genetic bottlenecks in some of these peripheral populations, the simulations performed to estimate the method's power to correctly infer the past demography of our empirical populations suggested that the timing and severity of bottlenecks could not be established with certainty. We urge caution against trying to relate demographic declines inferred using MSVAR with particular historic or climatological events.

In this study, we used genetic-based approaches to estimate population size and structure of Eurasian otter along the Drava River in Hungary, and compared these results to traditional survey-based methods. The relative spraint density of otter was estimated based on the number of fresh (D f ) and total number (D t ) of spraints collected on standard routes over a 2-year period. Nine microsatellite loci were screened, generating 17 individual otter genotypes composed of 45 different alleles. The expected heterozygosity ranged from 0.53 to 0.89 and observed heterozygosity from 0.25 to 0.92. The mean density (D g ) estimated over six different sites was 0.17 individuals per km of shoreline. A close correlation was found between the number of genotypes and spraint counts along a standard route (fresh spraints: r P ¼ 0.85, Po0.01; total spraints r P ¼ 0.76, Po0.05). All genotypes found within the 50 km-long study area were closely related (D m ranged between 0.08 and 0.21).

34Prey selection by carnivores can be affected by top-down and bottom-up factors. For 35 example, large carnivores may facilitate food resources for mesocarnivores by providing 36 carcasses to scavenge, however mesocarnivores may hunt large prey themselves, and their 37 diets might be affected by prey size and behaviour. We reviewed jackal diet studies and 38 determined how the presence of large carnivores and various bottom-up factors affected 39 jackal prey selection. We found 20 studies of black-backed jackals (Canis mesomelas) from 40 43 different times or places, and 13 studies of Eurasian golden jackals (Canis aureus) from 41 23 different times or places reporting on 3900 and 2440 dietary records (i.e. scats or stomach 42 contents), respectively. Black-backed jackals significantly preferred small (< 30 kg) ungulate 43 3 species that hide their young (duiker Sylvicapra grimmia, bushbuck Tragelaphus scriptus and 44 springbok Antidorcas marsupialis), and avoided large (> 120 kg) hider species and follower 45 species of any body size. They had a preferred and accessible prey weight range of 14-26 kg, 46 and a predator to ideal prey mass ratio of 1:3.1. Eurasian golden jackal significantly prefer to 47 prey on brown hare (Lepus europaeus; 4 kg), yielding a predator to preferred prey mass ratio 48 of 1:0.6, and a preferred and accessible prey weight range of 0 -4 kg and 0 -15 kg, 49 respectively. Prey preferences of jackals differed significantly in the presence of apex 50 predators, but it was not entirely due to carrion availability of larger prey species. Our results 51 show that jackal diets are affected by both top-down and bottom-up factors, because apex 52 predators as well as prey size and birthing behaviour affected prey preferences of jackals. A 53 better understanding of the factors affecting jackal prey preferences, as presented here, could 54 lead to greater acceptance of mesocarnivores and reduced human-wildlife conflict. 55 56 Introduction 57Adequate nutrition affects the fitness of an individual, and is crucial for its survival 58 and reproductive success. Therefore, natural selection should theoretically select for 59 behaviours that augment efficient feeding (Krebs, 1978). Optimal foraging theory states that 60 animals forage in a way that maximizes their net rate of energy intake and subsequently their 61 fitness; resulting in an optimal diet (Pyke, 1984; Pyke et al., 1977). While the evolutionary 62 adaptations of large carnivores to optimal foraging via preferential predation are well studied 63 (Clements et al., 2016; Hayward et al., 2016; Hayward et al., 2014; Krause and Godin, 1995), 64 the optimal foraging strategies of mesocarnivores are poorly known. These might be affected 65 by top-down factors, such as the presence of larger carnivores, as well as bottom-up factors, 66 such as prey size, abundance, behaviour and habitat. 67 4 Larger carnivores can affect the prey selection of mesocarnivores through competition 68 by: i) direct interference between individuals of the competing spec...