Food habits of the otter (Lutra lutra) in two habitats of the Doñana National Park, SW Spain

Food habits of otters Lutra lutra were studied in two localities of the Doñana National Park (SW Spain) 16 km apart. These were the lowest stretch of Arroyo Rocina, a eutrophic stream where American red-swamp-crayfish were introduced in 1976, and at Lucio Bolín, an artificial pond 150 m in diameter, situated on the border of the Guadalquivir marshes. In all, 598 spraints were analysed between 1979 and 1984. Crayfish, occurring in 80% of the spraints, was the dominant food item in Arroyo Rocina, where other common foods were fish (63%), insects (55%) and amphibians (18%). Fish, occurring in 94% of the spraints, were by far the most abundant food item in Lucio Bolin, followed by insects (32%) and amphibians (28%). Seasonal differences in diet were small but interesting: reptiles were eaten more often in the dry season (April-September) and insects and crayfish in the rainy season (October-March). Among fish, eels were more commonly eaten in the rainy period and the remaining species in the dry period. This pattern of seasonal variation is opposite to the usual in temperate Europe. Mean size of the captured eels was statistically higher in Lucio Bolin than in Arroyo Rocina. A large amount of very small fish such as Gambusia was eaten. A comparison of prey consumed with estimates of prey abundance reveals a strong preference for eels. The diet of Mediterranean European otters seems to be more diverse than that of northern European ones, including more insects, amphibians and reptiles.     

Diet of wild boar Sus scrofa in Western Europe, with particular reference to consumption of agricultural crops

1. The diet of wild boar Sus scrofa in Western Europe is reviewed, paying particular attention to the consumption of agricultural crops and the implications of this from the point of view of crop damage. Data were taken mainly from 11 studies that provide quantitative information about the consumption of different food types, but we also list all the foods reported as being eaten by wild boar in a total of 21 studies. 2. Vegetable foods occurred more frequently in the diet than animal foods, and also constituted the bulk of the food ingested. Overall, there were four major vegetable food categories: mast, roots, green plant matter and agricultural crops. Depending on the study area, wild boar always consumed at least one energy‐rich plant food such as acorns, beechnuts, chestnuts, pine seeds, olives, cereal grains or other crops. The number and types of agricultural crops consumed varied between study areas but crops represent an important component of wild boar diet throughout its Western European range. Among animal foods, insects, earthworms, birds and mammals were eaten most consistently but the diet also included amphibians, reptiles, gastropods and myriapods. 3. Seasonal, interannual and regional differences in the diet, together with its striking overall breadth, indicate that wild boar are opportunistic omnivores whose diet, in any particular instance, is largely determined by the relative availability of different food types. Dependence on energy‐rich plant material as a major component of the diet, coupled with large body size and a propensity to trample crops as well as consume them, means that wild boar cause significant agricultural damage.     

Feeding habits of invasive American mink (Neovison vison) in northern Germany—potential implications for fishery and waterfowl

In order to collect ecological data of invasive American mink (Neovison vison) at a fishpond area in northeastern Germany, we conducted a telemetry study in which 14 mink were radio-tracked. During this project, 2,502 scats from radio-tracked individuals were collected in the period from October 2003 to October 2005. Investigated mink principally prey on fish, small mammals and birds (eggs inclusive), whereas amphibians, reptiles and invertebrates were caught infrequently. Analysing mink scats of different seasons, we found significant seasonal variations of diet composition. In spring, fish, mammals and birds were hunted in similar amounts. During summer, birds made up the main part of the diet followed by mammals. In autumn, the proportion of birds in the mink diet decreased, whereas fish gained in importance. This trend continued during the winter period, when mink preyed almost exclusively on fish. Amphibians, crustaceans, insects, molluscs and reptiles were found only occasionally in scat samples. Among birds, the mink preyed mainly on the Eurasian Coot (Fulica atra) followed by the Mallard (Anas platyrhynchos). Mammalian prey was clearly dominated by the water vole (Arvicola terrestris) and among fish, mink hunted especially perch (Perca fluviatilis), roach (Rutilus rutilus) and carp (Cyprinus carpio). Results clearly demonstrate that mink is an opportunistic predator, which hunts its prey according to availability and vulnerability, respectively. Despite the high portions of fish in their autumn and winter diet, the economic damage caused by mink seems to be negligible. However, high predation rates on birds during the breeding season indicate a potential negative impact of mink on waterfowl.     

The food of the grayling Thymallus thymallus (L.) of the River Lugg, Herefordshire

The examination of the stomach contents of 253 grayling from the River Lugg has provided some evidence of a possible depression of feeding activity during the summer months. The diet was varied but bottom food predominated, especially insect larvae, Crustacea and molluscs. Some surface foods were taken but plant material was rarely eaten. Substrate material, detritus and debris and even large pebbles were eaten, mainly in summer. Most seasonal variations in the diet could be related to variations in availability. Fish were not eaten but cyprinid and salmonid eggs were eaten at the appropriate season. In general, increasing amounts of larger food items were eaten by the older grayling.     

Nature and variability of human food consumption.

The early human diet was characteristically extremely varied, and a wide range of plant species and plant organs were consumed. Foods of animal origin included those taken opportunistically, such as invertebrates, amphibians, reptiles, small mammals, birds and their eggs, and the scavenging and hunting of larger mammals. Each of these types of food have characteristic nutritional compositions. Comparison of these compositional features shows that an adequate diet could be obtained in many different ways. The selection of food providing fat had substantial advantages in reducing the amount of plant foods to be gathered, in the satiety provided and in supplying essential micronutrients. Obtaining adequate water and energy would probably be the main physiological drives. Many plant foods contain natural toxicants, and would only have been suitable as major items in the diet once cooking had been developed, and the preference for sweet tastes would have protected humans from eating bitter, toxic plants.     

Food habits of three carnivore species (Viverricula indica, Herpestes urva, and Melogale moschata) in Fushan Forest, northern Taiwan

The food habits and degrees of dietary overlap of lesser oriental civet ( Viverricula indica ), crab-eating mongoose ( Herpestes urva ), and ferret badger ( Melogale moschata ) inhabiting the Fushan Forest, northern Taiwan, were studied using faecal analysis between February 1993 and June 1994. Laboratory analysis of 154 civet faeces, and 174 mongoose faeces showed that both species fed on a wide variety of food items, including mammals, birds, reptiles, amphibians, fish, crustaceans, insects, oligochaetes, gastropods, chilopods, arachnids, and plants. Insects, oligochaetes, plants, and mammals were the four most important food items in the civets' diet, whereas crustaceans, insects, amphibians, and reptiles were the four most important food items consumed by mongooses. Amphibians were the only vertebrates, together with invertebrates and plants, found in the 64 ferret badger faeces we analysed, and oligochaetes, insects, and amphibians were the most important food items consumed by ferret badgers. The diversity of diet was highest in the mongoose, followed by the civet, and was lowest in the ferret badger.
The degree of dietary overlap was greatest between the civet and the ferret badger, followed by that of the civet and mongoose. The mongoose and ferret badger had the lowest degree of dietary overlap. However, the degree of dietary overlap varied in different seasons. Invertebrates were the most important food source for the carnivores in Fushan Forest.     

Diet of some species of Neotropical small mammals

Dietary analysis was performed to determine the variations in diet of some small neotropical species of mammals collected in seasonal areas of the cerrado (a savannah-like grassland) and semi-deciduous forest. Food items were determined based on the analysis of stomach contents of 126 animals (one didelphid and five sigmodontine rodent species). Most species presented herbivorous-omnivorous habits, with a preference for the vegetative parts of plants. Akodon montensis Thomas (1913) was the most abundant species in the forest area and demonstrated a uniform consumption of animal and vegetal items through the year, and contained 65.7% plant material in its diet. Necromys lasiurus (Lund, 1841) was the most abundant in the cerrado with 72.6% of vegetation in its diet, but showed a high consumption of animal items during the rainy season. Oligoryzomys nigripes (Olfers, 1818) contained 95.1% of plant material, while Oxymycterus delator (Thomas, 1903) consumed 61.6% invertebrates, mainly insects. The didelphid Philander frenatus (Olfers, 1818) consumed invertebrates (47.7%), small vertebrates (7.3%) and plant material (44.9%).     

The diet of feral cats on islands: a review and a call for more studies

Cats are among the most successful and damaging invaders on islands and a significant driver of extinction and endangerment. Better understanding of their ecology can improve effective management actions such as eradication. We reviewed 72 studies of insular feral cat diet from 40 islands worldwide. Cats fed on a wide range of species from large birds and medium sized mammals to small insects with at least 248 species consumed (27 mammals, 113 birds, 34 reptiles, 3 amphibians, 2 fish and 69 invertebrates). Three mammals, 29 birds and 3 reptiles recorded in the diet of cats are listed as threatened by the IUCN. However, a few species of introduced mammals were the most frequent prey, and on almost all islands mammals and birds contributed most of the daily food intake. Latitude was positively correlated with the predation of rabbits and negatively with the predation of reptiles and invertebrates. Distance from landmass was positively correlated with predation on birds and negatively correlated with the predation of reptiles. The broad range of taxa consumed by feral cats on islands suggests that they have the potential to impact almost any native species, even the smallest ones under several grams, that lack behavioral, morphological or life history adaptations to mammalian predators. Insular feral cat??s reliance on introduced mammals, which evolved with cat predation, suggests that on many islands, populations of native species have already been reduced.     

Tryptophanase in Diverse Bacterial Species

The distribution of tryptophanase was studied. The highest observed specific activity, mumoles per minute per milligram (dry weight) cells, is given in parentheses after each species. Tryptophanase was inducible and repressible in Escherichia coli (.914), Paracolobactrum coliforme (.210), Proteus vulgaris (.146), Aeromonas liquefaciens (.030), Photobacterium harveyi (.035), Sphaerophorus varius (.021), Bacteroides sp. (.048), and Corynebacterium acnes (.042). The enzyme was constitutive and nonrepressible in Bacillus alvei (.013), and was inducible but not repressible by glucose in Micrococcus aerogenes (.036). Indole-positive bacteria were found in fecal or intestinal samples from a variety of animals among the mammals, reptiles, insects, molluscs, fish, crustaceans, and amphibians.     

Relaciones tróficas de Trucha Marrón,Salmo fario Linné, y Trucha Arco Iris,Salmo gairdneri Richardson, (Osteichthyes,Salmoniformes) en un embalse norpatagónico

A detailed comparative study of the diet of wild brown and rainbow trout in the Ramos Mexía reservoir, Neuquén Province, during 1982 and 1983 was made. The seasonal composition of both diets was determined, calculating number, volume, and occurrence. The feeding habits of the brown trout are based mainly on perch, silverside, galaxiids, molluscs, and crustaceans; for rainbow trout, galaxiids, terrestrial insects, ostracods, crustaceans, and molluscs were recorded. Fishes were mainly caught throughout the year by brown trouts, while rainbow trouts capture mostly ostracods during spring and galaxiids throughout the rest of the year. A decrease in the percentage of galaxiids, insects, and molluscs was observed with the increase of brown trout size, while increasing that of silverside. Rainbow trouts also showed an increase in perch and galaxiids predation with size, with a decrease in crustaceans and insects. A diet overlap was recorded only in spring. Trouts occupy both the 3rd and 5th level in the trophic chain, being very active ichthyofagous predators.     

Public health importance of Angiostrongylus cantonensis and its relatives

Species of Angiostrongylus are fairly common nematode parasites of a variety of small mammals, but some species - particularly A. cantonensis and A. costaricensis - are increasingly seen as human infections. The worms make use of a range of aquatic, amphibious or terrestrial gastropod molluscs as intermediate hosts, which become infected by ingestion of eggs shed in the faeces of infected mammals. Porotenic hosts, including crustaceans, amphibians and reptiles, are known for most Angiostrongylus species, and can also be a source of the infective third-stage larvae that initiate mammalian infections.     

Geographical variation in genet (Genetta genetta L.) diet: a literature review

The geographical variation in the Genet Genetta genetta L. diet was analysed from 12 locations covering its entire range. Data were obtained from the available literature on food studies in this species. We studied the general food spectrum of this species and compared the importance of different prey items in each area through PCA analysis. The possible influence of some large-scale environmental factors (latitude, altitude, Mediterraneity) on diet were studied by means of regression analysis and anova . The study assessed the frequency of occurrence of each prey group and diet diversity. Results show the existence of two ‘food’ groups: (i) Genets which feed on a wide food spectrum, especially arthropods and (ii) Genets which feed on small mammals at a high frequency, while the remaining prey items are scarce or absent. At the intraspecific level, Genets behave as generalist species, with the small mammals (especially, the Woodmouse) as the most outstanding prey item. However, when compared with the diet of other medium-sized Palaearctic carnivores, we can say that the Genet is intermediate between typical generalists (Martens Martes spp., Red Foxes Vulpes vulpes and Badgers Meles meles) and specialists (Otters Lutra lutra, Stoat Mustela erminea and Weasel Mustela nivalis). Finally, anova shows the existence of a relationship between diet diversity and Mediterraneity (associated with taxa such as arthropods, reptiles and amphibians), but no relationship was found for latitude or altitude. The importance of interspecific competition, based on island data, is discussed.     

Expression pattern of three-finger toxin and phospholipase A2 genes in the venom glands of two sea snakes, Lapemis curtus and Acalyptophis peronii : comparison of evolution of these toxins in land snakes, sea kraits and sea snakes

Background  

Snake venom composition varies widely both among closely related species and within the same species, based on ecological variables. In terrestrial snakes, such variation has been proposed to be due to snakes' diet. Land snakes target various prey species including insects (arthropods), lizards (reptiles), frogs and toads (amphibians), birds (aves), and rodents (mammals), whereas sea snakes target a single vertebrate class (fishes) and often specialize on specific types of fish. It is therefore interesting to examine the evolution of toxins in sea snake venoms compared to that of land snakes.     

The autecology of the chub, Squalius cephalus (L.), of the River Lugg and the Afon Llynfi

(1) Seasonal variation in the intensity of feeding activity was demonstrated in two chub populations. Feeding activity was higher in summer and more pronounced in the young age-classes. The intensity of feeding activity was significantly correlated with temperature. (2) The diet of the total chub populations embraced a wide range of food items but vegetable material predominated. Substrate material was frequently encountered which suggested considerable feeding on the river bed. Fish were the most important animal food, by volume, in the River Lugg but Trichoptera larvae were most important in the Afon Llynfi. No remains of salmon parr or trout were found in chub stomachs but grayling were eaten. The most important prey fish, by volume, was the eel but cyprinids, especially minnows, were most important by frequency of occurrence. (3) Seasonal variation in the composition of the diet could be related to availability of food organisms but some selection was shown. Vegetable foods were most important in summer; animal foods, Trichoptera larvae in particular, were important in winter. (4) Analysis of the variation in the composition of the diet with age revealed several trends, notably a decrease in the importance of plant material, aquatic and aerial insects with age and a corresponding increase in the importance of larger prey foods such as fish, frogs and crayfish. (5) The commonly held view that chub are deleterious to salmonid stocks was examined. The absence of direct predation and the small likelihood of direct competition suggests that this view is incorrect.     

Changes in the Montagu’s Harrier Circus pygargus diet in Eastern Poland across decades promote insects and reptilians,but not birds and rodents

We investigated temporal changes in diet composition of the Montagu''s Harrier Circus pygargus breeding in natural habitat (calcareous peat bog) in SE Poland. We characterized diet composition in a three‐year period (2007–2009), based on pellet analyses. We investigated whether diet composition was affected by years or stage of breeding. We compared diet of the studied population between 2000s and 1990s and with other populations. We found that the food of the studied population was dominated by insects and mammals (by number) and mammals and birds (by biomass). Biomass and abundance of main prey items differed between studied years because of different air temperatures. We found some interannual differences in contribution of some prey items including higher number of thermophilic prey (insects and amphibians) in warmer years. Comparison of pellet composition in the 1990s and 2000s revealed significant increase in the abundance of thermophilic prey (insects and reptiles) and decrease of mammals including Microtus voles and birds. Those changes may be linked to habitat changes in areas neighboring peat bogs and climate change‐induced changes in prey communities. The studied population was able to respond to changes in foraging habitats and prey composition by opportunistic foraging on easily available prey. The diet of the studied population is the most similar to the geographically closest populations foraging in similar habitats and characterized by high contribution of insects.     

Non-selective predator – the versatile diet of Amur sleeper (Perccottus glenii Dybowski, 1877) in the Vistula River (Poland), a newly invaded ecosystem

The Amur sleeper diet spectrum was investigated in addition to its spatial, seasonal and size-related changes, in order to predict which groups of native prey would be most affected by this exotic predator that has rapidly invaded many Eastern and Central European inland waters in recent decades. In total, 527 Perccottus glenii individuals were collected in four sites in the Włocławski Reservoir (the Vistula River, Baltic basin, Poland). Altogether 50 food categories were identified, including crustaceans, insects, molluscs, annelids, araneids, fishes and amphibians. Most of them were associated with aquatic vegetation, indicating that the Amur sleeper collects its prey from the submerged plants rather than directly from the bottom sediments. Amphipods and chironomid larvae, supplemented by zygopteran larvae and molluscs, composed the main forage base in all studied sites, although their importance was varied. The diet composition differed among P. glenii size-groups. Significant variation was found in numeric abundance of amphipods, chironomid larvae, fish and zygopteran larvae (Kruskal–Wallis P < 0.01). Seasonal changes in the diet were also observed whereby in spring and summer, dipteran larvae and amphipods were prevalent food items; the importance of molluscs and zygopteran larvae increased considerably in September; and fish showed the highest occurrence in June, July and August. The broad diet spectrum of the Amur sleeper indicates that it is a non-selective, opportunistic predator and that several taxonomic groups of native hydrofauna as well as macroinvetebrates and fish may be affected by its presence. The highly flexible feeding strategy undoubtedly favours Amur sleeper expansion in invaded watersheds.     

Conserved polymerase chain reaction primers fail in diagnosis of parasitic infections

We demonstrate that a set of previously described polymerase chain reaction primers used for detection of hemogregarines in reptiles will also amplify the same region of the 18S rRNA gene of reptiles, amphibians, mammals, and insects and thus should not be used for molecular diagnosis. These same primers have also been used to differentiate 2 species of Plasmodium that infect lizards. We provide evidence that the observed variance may have been dependent on parasitemia and not representative of actual molecular differences between the 2 parasite species.     

Evolution of proteins of macroglobulin family

The first representatives of proteins of the macroglobulin family appeared 500–700 million years ago. At present representatives of this family have been revealed in crustaceans, molluscs, fish, amphibians, reptiles, ticks, insects, birds, and mammals, the macroglobulin family in blood of some species being represented simultaneously by several proteins that have different molecular weight and partly duplicate functions of each other. In different species, they are present as monomers, dimers, or tetramers. The distinguishing feature of each protein subunit is the presence of a “trap” with cyclic thioether on the bottom and of a sufficiently large hydrophobic area. All representatives are able to form complexes with different regulatory substances through covalent or hydrophobic bonds, which allows them to perform a wide range of regulatory functions. The ancient origin, evolutionary conservatism, widespread presence, and a diversity of regulatory functions permit proteins of the macroglobulin family to be considered as the main regulatory biomolecules of organism fluid media.     

湖北神农架国家级自然保护区两栖爬行动物物种多样性

对神农架自然保护区两栖爬行动物进行调查,整理了神农架自然保护区两栖爬行动物名录共71种,新发现湖北省新分布种6种,其中腾格里蛙Rana tenggerensis Zhao,Macey et Papenfuss、宁陕小头蛇 Oligodon ningshaanensis Yuan离原分布区较远,神农架新分布种3种,神农架两栖爬行动物的区系特征以东洋界(74.69%)为主,广布种(18.31%)、古北界(7%)种类次之,体现了南北混杂的特点.随着海拔的升高,两栖爬行动物生物多样性总体呈下降趋势,400～1600 m两栖爬行动物生物多样性最高,随海拔下降的趋势不明显,1900 m以上多样性急剧下降.     

On the relationship between chitin particle size and digestibility in the primate Galago senegalensis

Experiments were performed to examine the relationship between the particle size of chitin and its digestibility in the small insectivorous prosimian Galago senegalensis. In the first set of experiments, four animals were fed a 25% chitin diet with the chitin particles less than or equal to 60-mesh (0.250 mm maximum diameter). On average, the animals digested 22.5 ± 2.2 percent of the ingested chitin. In the second set of experiments, the four animals were fed a 25% chitin diet with the chitin particles ground to ≤ 40- and ≥ 45-mesh (between 0.425 and 0.325 mm). On average, the animals digested 2.75 ± 1.38 percent of the ingested chitin. There was no significant variation between the performance of any of the animals on either the 60- or 40–45-mesh trials. In all instances, however, each animal digested significantly more of the 60-mesh chitin and the 40–45-mesh chitin. These experiments demonstrate the importance of masticatory efficiency among small mammals for improving the digestibility of foods such as insects which contain high proportions of chitin. They also suggest why insectivorous and folivorous primates have certain convergent dental specializations for finely grinding their foods. Both leaves and insects contain relatively indigestible structural carbohydrates. These substances are much more completely digested when the surface area to volume ratio of the swallowed material is increased. The masticatory efficiency of frugivorous primates is much lower since the constituents of these foods are relatively completely digested irrespective of the fineness of grinding.