@article{EccardFeyCaspersetal.2011, author = {Eccard, Jana and Fey, Karen and Caspers, Barbara A. and Yl{\"o}nen, Hannu}, title = {Breeding state and season affect interspecific interaction types indirect resource competition and direct interference}, series = {Oecologia}, volume = {167}, journal = {Oecologia}, number = {3}, publisher = {Springer}, address = {New York}, issn = {0029-8549}, doi = {10.1007/s00442-011-2008-y}, pages = {623 -- 633}, year = {2011}, abstract = {Indirect resource competition and interference are widely occurring mechanisms of interspecific interactions. We have studied the seasonal expression of these two interaction types within a two-species, boreal small mammal system. Seasons differ by resource availability, individual breeding state and intraspecific social system. Live-trapping methods were used to monitor space use and reproduction in 14 experimental populations of bank voles Myodes glareolus in large outdoor enclosures with and without a dominant competitor, the field vole Microtus agrestis. We further compared vole behaviour using staged dyadic encounters in neutral arenas in both seasons. Survival of the non-breeding overwintering bank voles was not affected by competition. In the spring, the numbers of male bank voles, but not of females, were reduced significantly in the competition populations. Bank vole home ranges expanded with vole density in the presence of competitors, indicating food limitation. A comparison of behaviour between seasons based on an analysis of similarity revealed an avoidance of costly aggression against opponents, independent of species. Interactions were more aggressive during the summer than during the winter, and heterospecific encounters were more aggressive than conspecific encounters. Based on these results, we suggest that interaction types and their respective mechanisms are not either-or categories and may change over the seasons. During the winter, energy constraints and thermoregulatory needs decrease direct aggression, but food constraints increase indirect resource competition. Direct interference appears in the summer, probably triggered by each individual's reproductive and hormonal state and the defence of offspring against conspecific and heterospecific intruders. Both interaction forms overlap in the spring, possibly contributing to spring declines in the numbers of subordinate species.}, language = {en} } @article{ReilRosenfeldImholtetal.2017, author = {Reil, Daniela and Rosenfeld, Ulrike M. and Imholt, Christian and Schmidt, Sabrina and Ulrich, Rainer G. and Eccard, Jana and Jacob, Jens}, title = {Puumala hantavirus infections in bank vole populations}, series = {BMC ecology}, volume = {17}, journal = {BMC ecology}, publisher = {BioMed Central}, address = {London}, issn = {1472-6785}, doi = {10.1186/s12898-017-0118-z}, pages = {13}, year = {2017}, abstract = {Background In Europe, bank voles (Myodes glareolus) are widely distributed and can transmit Puumala virus (PUUV) to humans, which causes a mild to moderate form of haemorrhagic fever with renal syndrome, called nephropathia epidemica. Uncovering the link between host and virus dynamics can help to prevent human PUUV infections in the future. Bank voles were live trapped three times a year in 2010-2013 in three woodland plots in each of four regions in Germany. Bank vole population density was estimated and blood samples collected to detect PUUV specific antibodies. Results We demonstrated that fluctuation of PUUV seroprevalence is dependent not only on multi-annual but also on seasonal dynamics of rodent host abundance. Moreover, PUUV infection might affect host fitness, because seropositive individuals survived better from spring to summer than uninfected bank voles. Individual space use was independent of PUUV infections. Conclusions Our study provides robust estimations of relevant patterns and processes of the dynamics of PUUV and its rodent host in Central Europe, which are highly important for the future development of predictive models for human hantavirus infection risk}, language = {en} } @article{DrygalaZoller2013, author = {Drygala, Frank and Zoller, Hinrich}, title = {Spatial use and interaction of the invasive raccoon dog and the native red fox in Central Europe - competition or coexistence?}, series = {European journal of wildlife research}, volume = {59}, journal = {European journal of wildlife research}, number = {5}, publisher = {Springer}, address = {New York}, issn = {1612-4642}, doi = {10.1007/s10344-013-0722-y}, pages = {683 -- 691}, year = {2013}, abstract = {The main objective was to discover extent of interference and/or exploitative competition between the native red fox (Vulpes vulpes) and the introduced, invasive raccoon dog (Nyctereues proconoides) in the intensively used, agricultural landscape of northeast Germany (Mecklenburg-Western Pomerania) using very high frequency (VHF) radio telemetry. We recorded location data for 12 foxes and 16 raccoon dogs between July 2004 and December 2006. Species had similar average home range sizes estimated in each season (K95). Home ranges of adjacent raccoon dogs and foxes overlapped from 0.5 to 74.5 \% with a mean of 26.4 \%. We found a significantly different home range overlap index between the species showing that raccoon dog ranges shifted between seasons to a greater extent than red fox ranges. The raccoon dog differed significantly from the red fox in its use of habitat types, preferring dense vegetation cover and avoiding open areas. The red fox displayed less preference for or avoidance of specific habitat types. Moreover, an almost neutral inter-specific interaction index ranging from -0.12 to 0.12 indicates that raccoon dogs and red foxes ignored each other. It is concluded that widespread and available resources and differences in spatial use patterns prevent competition between red foxes and raccoon dogs in the agricultural landscape of northeast Germany.}, language = {en} }