Diet composition of the golden jackal (Canis aureus, L.) in Bulgaria, where the largest jackal population in Europe occurs, has been studied by scat analysis in a typical and newly occupied agricultural environment. The study was carried out during late summer and early autumn, a period when small mammal density is high. The food of the jackal typically consisted of small-sized and wild-living prey species. Rodents have been found to represent the primary food of the jackal (biomass estimation: 59.3 %, mainly Microtus spp.), and the European brown hare (Lepus europaeus, 20.1 %) and plants (19.7 %, mainly fruits) are secondary foods. Other prey, such as birds (mainly passerines), reptiles and invertebrates had been consumed in a low biomass ratio. No remains of wild ungulate and domestic animals have been detected in the studied scats.
The diet of the barn owl from three localities in Thessaly, Central Greece, was studied in the breeding and non breeding seasons over one year. A total of 420 pellets with 1.013 prey items were analyzed. Twelve small mammalian species were taken (94.9% by number and 96.1% by biomass), although Mus domesticus (26.3%), Crocidura spp. (25.3%) and Apodemus spp. (18.4%) were the main species predated by number. Rats (Rattus spp.), showed the highest frequency (11%) and biomass percentages observed to date in Greece, and their presence in the barn owl diet is also among the highest in the Mediterranean Europe. Birds (Passer spp. and Carduelis spp.) and insects (Acrididae) were also present (3.9% and 1.2%, respectively). Ecological niche values, seasonal and geographical differences were tested, the results pointing to the opportunistic feeding behavior of the barn owl in the croplands of central Greece.
The diet of the polecat (Mustela putorius) was studied by analysing 1078 scats collected in extensive farmland in Poland between 2006 and 2008. The diet included a wide variety of prey species; the main component were rodents (51.7 % of biomass), mainly Microtus arvalis. Birds were the second most common group in the diet (%Fr = 4.5). Anurans, reptiles, invertebrates and other items were additional elements of the diet. Seasonal comparisons reveal differences in diet. Rodents and birds were exploited throughout the year. Other mammals and carrion were the main component of a winter diet, whereas in spring amphibians and reptiles were characteristic prey. Diet of polecat from the studied agricultural landscape in Poland was more similar to diet of population from Hungary than to France. All these patterns confirm that polecat is a food generalist with almost exclusively carnivorous diet and can easily exploit different food resources.
The maximum size of ingested ball-shaped particles was determined in three species of adult dung feeding beetle: Anoplotrupes (Geotrupes) stercorosus and Geotrupes spiniger (Geotrupidae, Geotrupinae) and Sphaeridium lunatum (Hydrophilidae, Sphaeridiinae). Maximum diameters were 40-65 µm, 60-75 µm and 16-19 µm in A. stercorosus, G. spiniger and S. lunatum, respectively, and it was concluded that these beetles feed in the same way as found in previous studies on coprophagous scarabaeids (Scarabaeinae and Aphodiinae). Coarse particles, mainly indigestible plant fragments, are rejected by an unknown filtering mechanism, and only very small particles are actually ingested. The two geotrupids, however, tolerate somewhat larger particles than do scarabaeines of similar size. This may reflect a lower degree of specialisation towards dung feeding in the geotrupids than in the scarabaeines. In several ways, the mouthparts of the coprophagous Scarabaeidae, Geotrupidae and Hydrophilidae show essentially the same morphological modifications that must be adaptations for dung feeding. For the hydrophilid (Sphaeridium), such modifications are described for the first time. They include asymmetric mandibular molars (right convex, left concave), fitting exactly into each other, with highly specialised surfaces that may concentrate the food prior to ingestion by squeezing fluid out of it. Other examples are the conjunctives (scarabaeids and geotrupids) or similar structures (the hydrophilid) and the large, hairy, pad-like distal lobes of the maxillar galeae. Provided that current views on the evolutionary history of these beetles are correct, dung feeding has arisen independently in the Scarabaeidae, Geotrupidae and Hydrophilidae. If so, the feeding on very small particles and the concomitant modifications of mouthparts in these three groups must be results of parallel evolution.
Food webs are of crucial importance for understanding any ecosystem. The accuracy of food web and ecosystem models rests on the reliability of the information on the feeding habits of the species involved. Water boatmen (Corixoidea) is the most diverse superfamily of water bugs (Heteroptera: Nepomorpha), frequently the most abundant group of insects in a variety of freshwater habitats worldwide. In spite of their high biomass, the importance of water boatmen in aquatic ecosystems is frequently underestimated. The diet and feeding habits of Corixoidea are unclear as published data are frequently contradictory. We summarise information on the feeding habits of this taxon, which exemplify the difficulties in evaluating published data on feeding habits in an invertebrate taxon. It is concluded that Corixoidea are, unlike other true bugs, capable of digesting solid food, but their feeding habits are still insufficiently known. The dominant feeding strategy in this taxon is zoophagy, but several species consume other foods, particularly algae and detritus. Only members of the subfamily Cymatiainae seem to be exclusively predators. In other subfamilies, the diet of different species and different sexes or populations of a single species may vary depending on the food available or is still unknown. We conclude, that a multi-method approach is needed to elucidate the feeding habits of aquatic insects and invertebrates in general., Christian W. Hädicke, Dávid Rédei, Petr Kment., and Obsahuje bibliografii
The aim of this study is to evaluate how wolves affected the prey community in a newly recolonization area of the Western Alps, the Gran Paradiso National Park (GPNP). Since 1960’s, this portion of the Alps hosts a multi-specific wild ungulate community. It lived in absence of large predators for more than a century. In 2006 a couple of wolves re-established in GPNP and in summer 2007 the first reproduction was documented. The present study was conducted during the following two years. In term of biomass
consumed (Bio%), Alpine chamois was the main prey of wolves in all seasons (Bio% Summer 2007 = 70.13; Bio% Winter 2007/2008 = 56.99; Bio%Summer 2008 = 67.52; Bio% Winter 2008/2009 = 36.35), while roe deer were intensely consumed during the adverse season (Bio% W2007/2008
= 23.05 %; Bio% W2008/2009 = 42.47 %). Although cervids were much less abundant than bovids in the area, they represented one of the main
food items of wolves, possibly because of the strong habitat overlap and altitude use between predator and preys. Moreover, the minor adaptation of cervids to the Alpine environment compared to bovids could affect their vulnerability and thus the respective consumption of the different species during the adverse season.