Hermann Ansorge

Feeding ecology of wolvesCanis lupus returning to Germany

Following several years of occasional occurrence, several wolvesCanis lupus Linnaeus, 1758 have established a resident population in northeastern Saxony (Eastern Germany). From 2001 to 2003, we collected and analysed 192 scats ofC. lupus. Results of our study are expressed as the frequency of occurrence of prey species and the percentage of biomass consumed using coefficients of digestibility as well as two variants of an equation for prey mass per collectable scat. Diet composition of the wolves was restricted to a few food items, mostly wild ungulates. These remains were found in 97% of the scats, representing 99% of the biomass consumed by the wolves. Roe deerCapreolus capreolus was the most frequent and most important prey, constituting nearly of one half the biomass. Red deerCervus elaphus was recorded in one-third of the samples, followed by wild boarSus scrofa, mouflonOvis am mon musimon and brown hareLepus europaeus. Compared with game occurrence, roe deer was clearly preferred over the other species. A difference between winter and summer diets was mainly due to the high occurrence of young wild boar in summer. The general diet pattern of the wolf in Saxony corresponds with that found in the naturally occurring populations in Europe.

Diet of the raccoon dog Nyctereutes procyonoides — a canid with an opportunistic foraging strategy

We examined the raccoon dog’s Nyctereutes procyonoides (Gray, 1834) diet in two agricultural landscapes of Germany and compared these results with other diet studies from its native and introduced ranges. The diet composition was influenced as well by the landscape structures as by the seasons: in the waterrich study area 2 amphibians (54.1%) and fish (10.8%) occurred more frequently in the samples. In study area 1 amphibians (19.0%) and invertebrates (69.4%) gained more significance in the diet in summer, whereas in winter samples maize (32.8%) was an important food item. The diet composition shifted according to the availability of different food items. Raccoon dogs, ability to feed temporarily on one food source may possibly cause a serious problem to endangered small populations of birds and amphibians. The review of 81 data sets from nine countries showed that seasons and locality affected the occurrence of most food items. However, comparable to the present study, small mammals, insects and plants were identified as important food items both in native and introduced ranges of the raccoon dog. In regard to its diet composition, gathering foraging strategy and inactivity during winter, the raccoon dog probably preys less often on game animals and birds than the native red fox Vulpes vulpes.

Mortality patterns of otters (Lutra lutra) from eastern Germany

Data obtained from the dissection of 1067 otters Lutra lutra were used to compare the causes of mortality in relation to age composition, time trends, and regions. Age determination was based on the analysis of incremental cementum lines in teeth. Major causes of mortality of otters were traffic accidents (69.9%), followed by natural deaths (6.6%), deaths in fish-traps (6%), hunting (4.1%), and other violent events (4.4%). No significant differences in mortality structure between the sexes were found. Resulting from a log-linear and a contrast analysis, significant differences in frequencies of mortality causes in relation to different time periods, regions and age classes of otters were observed. The frequency of otters dying from hunting or diseases was highest in youngest (AC I) and oldest (AC V) otters. Generally, the greatest differences between age classes resulted from comparison of frequencies of traffic-mortality, hunting, and fish-traps. Concerning time trends, the greatest differences were found in the periods before and after 1990. In addition to the increase of traffic-mortality, hunting and deaths in fish-traps influenced the distribution of mortality in different time periods. In eastern Germany, there is a clear difference in mortality between northern and southern regions. This results mainly from commercial fish-trapping being more common at the northern coast and lakes. However, in all different subsamples of time, region or age-class, traffic-killed otters amounted to >50% of all otters found dead.

Detection of shrew-borne hantavirus in Eurasian pygmy shrew (Sorex minutus) in Central Europe

Recently, it was found that not only rodents but also shrews are reservoir hosts of hantaviruses. In Central Europe, only Seewis virus, associated with the Eurasian common shrew (Sorex araneus), has been recognized until now. In the present report, tissue samples from shrews belonging to Crocidurinae and Soricinae subfamilies, trapped in Czech Republic, Germany, and Slovakia, were screened for the presence of novel hantaviruses. Three new hantavirus partial L-segment sequences were obtained from pygmy shrews (Sorex minutus) trapped in Czech Republic and Germany. Complete nucleocapsid protein- and glycoprotein precursor-coding S- and M-segment sequences were then determined for the newly recognized hantavirus strains, CZ/Beskydy/412/2010/Sm, CZ/Drahany/420/2010/Sm, and DE/Dürrbach/1912/2009/Sm. Phylogenetic analyses showed that they represent strains of Asikkala virus (ASIV), a novel hantavirus also found in pygmy shrews from Finland. Our study reveals a broad geographic distribution of ASIV across Europe and indicates pygmy shrew as the primary reservoir host. Future studies will have to determine the pathogenic relevance of ASIV.

Adhesion of human and animal escherichia coli strains in association with their virulence-associated genes and phylogenetic origins

ABSTRACT Intestinal colonization is influenced by the ability of the bacterium to inhabit a niche, which is based on the expression of colonization factors. Escherichia coli carries a broad range of virulence-associated genes (VAGs) which contribute to intestinal (inVAGs) and extraintestinal (exVAGs) infection. Moreover, initial evidence indicates that inVAGs and exVAGs support intestinal colonization. We developed new screening tools to genotypically and phenotypically characterize E. coli isolates originating in humans, domestic pigs, and 17 wild mammal and avian species. We analyzed 317 isolates for the occurrence of 44 VAGs using a novel multiplex PCR microbead assay (MPMA) and for adhesion to four epithelial cell lines using a new adhesion assay. We correlated data for the definition of new adhesion genes. inVAGs were identified only sporadically, particularly in roe deer (Capreolus capreolus) and the European hedgehog ( Erinaceus europaeus). The prevalence of exVAGs depended on isolation from a specific host. Human uropathogenic E. coli isolates carried exVAGs with the highest prevalence, followed by badger (Meles meles) and roe deer isolates. Adhesion was found to be very diverse. Adhesion was specific to cells, host, and tissue, though it was also unspecific. Occurrence of the following VAGs was associated with a higher rate of adhesion to one or more cell lines: afa-dra, daaD, tsh, vat, ibeA, fyuA, mat, sfa-foc, malX, pic, irp2, and papC. In summary, we established new screening methods which enabled us to characterize large numbers of E. coli isolates. We defined reservoirs for potential pathogenic E. coli. We also identified a very broad range of colonization strategies and defined potential new adhesion genes.

Reproduction and Mortality of Invasive Raccoon Dogs (Nyctereutes procyonoides) in the Białowieża Primeval Forest (Eastern Poland)

We investigated reproduction and mortality of raccoon dogs (Nyctereutes procyonoides) in the Białowieża Primeval Forest (eastern Poland). The species invaded the forest in 1955 and is more common than native species of medium-sized carnivores. The mean litter size of raccoon dogs, based on placental scars and foetuses was 8.4 (SD = 2.0). Mortality of pups was 61% during the first three months following parturition. Of 82 cases of raccoon dog deaths recorded from 1996 to 2006, 55% were caused by natural factors (predation and diseases), 40% were human-related (vehicle collisions, harvest, poaching), and 5% were indeterminable. Rabies was the most important disease. The main predators of raccoon dogs were wolves (Canis lupus) and domestic dogs (Canis familiaris). Almost all raccoon dogs killed by cars were dispersing juveniles. We did not find differences in causes of mortality between collared and uncollared individuals. The annual survival rate of radio-tracked raccoon dogs (n = 18, 1997–2000) was 0.38 (SD = 0.05), and did not differ between males and females. Survival of raccoon dogs varied seasonally. It was highest in winter (0.82) when raccoon dogs settle in burrows, which may protect them against predation. The life table constructed based on the age at death indicates that mortality was highest in the first year of the raccoon dog life (0.82), and lower in the following years (0.58–0.68). Most raccoon dogs (98%) died during the first three years of their life and the maximum life span was 7 years. Life expectancy at birth was 0.8 years.

Historical Invasion Records Can Be Misleading: Genetic Evidence for Multiple Introductions of Invasive Raccoons (Procyon lotor) in Germany

Biological invasions provide excellent study systems to understand evolutionary, genetic and ecological processes during range expansions. There is strong evidence for positive effects of high propagule pressure and the associated higher genetic diversity on invasion success, but some species have become invasive despite small founder numbers. The raccoon (Procyon lotor) is often considered as a typical example for such a successful invasion resulting from a small number of founders. The species’ largest non-native population in Germany is commonly assumed to stem from a small number of founders and two separate founding events in the 1930s and 1940s. In the present study we analyzed 407 raccoons at 20 microsatellite loci sampled from the invasive range in Western Europe to test if these assumptions are correct. Contrary to the expectations, different genetic clustering methods detected evidence for at least four independent introduction events that gave rise to genetically differentiated subpopulations. Further smaller clusters were either artifacts or resulted from founder events at the range margin and recent release of captive individuals. We also found genetic evidence for on-going introductions of individuals. Furthermore a novel randomization process was used to determine the potential range of founder population size that would suffice to capture all the alleles present in a cluster. Our results falsify the assumption that this species has become widespread and abundant despite being genetically depauperate and show that historical records of species introductions may be misleading.

Inconsistency of biochemical evolutionary rates affecting allozyme divergence within the genus Apodemus (Muridae: Mammalia)

Abstract Within the rodent family Muridae, eight species of the genera Apodemus, Mus and Rattus were examined for allozyme differentiation in 29 proteins encoded by 36 presumptive genetic loci. Representatives of the families Arvicolidae ( Microtus arvalis, Clethrionomys glareolus ) and Cricetidae ( Cricetus cricetus ) were used as outgroups. Thirty-three loci were found to be polymorphic within species and differentially diagnostic between species, respectively. Rooted and unrooted dendrograms, based on various genetic distances, revealed relationships between A. sylvaticus, A. flavicollis and A. microps as well as between M. musculus, M. spretus and M. caroli , which are consistent with the results of previous investigations. In contrast, A. agrarius showed a greater genetic distance to the other Apodemus species than either Rattus or Mus . Based on a Hennigian cladogram and on results of DNA investigations performed by other authors, this result was interpreted to be due to an increased rate of allozyme evolution in this species rather than to a very isolated position within the Muridae. Concerning intergeneric relationships, a UPGMA-tree unequivocally suggested Mus to be the sister group of Apodemus , whereas the cladogram revealed the ambiguous position of this genus in relation to Mus and Rattus . As demonstrated by comparison of two fundamentally different methods for estimating divergence times, this result can be explained by a rapid separation of the genera in question during extensive adaptive radiation. As a consequence of unequal rates of allozyme evolution among taxa, use of both numerical and cladistic approaches for the evaluation of phylogenies is emphasized.

Detection of rat hepatitis E virus in wild Norway rats (Rattus norvegicus) and Black rats (Rattus rattus) from 11 European countries

Rat hepatitis E virus (HEV) is genetically only distantly related to hepeviruses found in other mammalian reservoirs and in humans. It was initially detected in Norway rats (Rattus norvegicus) from Germany, and subsequently in rats from Vietnam, the USA, Indonesia, China, Denmark and France. Here, we report on a molecular survey of Norway rats and Black rats (Rattus rattus) from 12 European countries for ratHEV and human pathogenic hepeviruses. RatHEV-specific real-time and conventional RT-PCR investigations revealed the presence of ratHEV in 63 of 508 (12.4%) rats at the majority of sites in 11 of 12 countries. In contrast, a real-time RT-PCR specific for human pathogenic HEV genotypes 1-4 and a nested broad-spectrum (NBS) RT-PCR with subsequent sequence determination did not detect any infections with these genotypes. Only in a single Norway rat from Belgium a rabbit HEV-like genotype 3 sequence was detected. Phylogenetic analysis indicated a clustering of all other novel Norway and Black rat-derived sequences with ratHEV sequences from Europe, the USA and a Black rat-derived sequence from Indonesia within the proposed ratHEV genotype 1. No difference in infection status was detected related to age, sex, rat species or density of human settlements and zoological gardens. In conclusion, our investigation shows a broad geographical distribution of ratHEV in Norway and Black rats from Europe and its presence in all settlement types investigated.

Hair density in the Eurasian otter Lutra lutra and the Sea otter Enhydra lutris

The hair density of adult Eurasian otters Lutra lutra (Linnaeus, 1758) and sea otters Enhydra lutris (Linnaeus, 1758) was analysed using skin samples taken from frozen carcasses. Lutra lutra exhibited a mean hair density of about 70 000 hairs/cm2 (whole body, appendages excepted), the mean individual density ranging from about 60 000 to 80 000 hairs/cm2. The dominant hair type were secondary hairs (wool hairs), the hair coat comprising only 1.26% of primary hairs (PH). Secondary hair (SH) density remained constant over the body (appendages excepted), whereas a few variations in PH density were observed. Neither an influence of the sex, nor a seasonal variation of the hair coat was found, moulting seems to be continuous. Enhydra lutris had a hair density between 120 000 and 140 000 hairs/cm2, the primary hairs representing less than 1% within the hair coat. Hair density remained quite constant over the regions of the trunk but was lower at the head (about 60 000 hairs/cm2 on the cheek). The hair follicles were arranged in specific groups with different bundles of varying size, normally comprising dominant numbers of wool hair (SH) follicles. Invariably there was always a large central primary hair follicle and numerous sebaceous glands between the bundles and principally around the PH follicles. The results are discussed related to possible ecological influences on hair coat density.