TY - JOUR A1 - Eccard, Jana A1 - Fey, Karen A1 - Caspers, Barbara A. A1 - Ylönen, Hannu T1 - Breeding state and season affect interspecific interaction types indirect resource competition and direct interference JF - Oecologia N2 - 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. KW - Rodents KW - Aggression KW - Seasonality KW - Space use KW - Winter biology Y1 - 2011 U6 - https://doi.org/10.1007/s00442-011-2008-y SN - 0029-8549 SN - 1432-1939 VL - 167 IS - 3 SP - 623 EP - 633 PB - Springer CY - New York ER - TY - JOUR A1 - Hoffmann, Julia A1 - Schirmer, Annika A1 - Eccard, Jana T1 - Light pollution affects space use and interaction of two small mammal species irrespective of personality JF - BMC Ecology N2 - Background: Artificial light at night (ALAN) is one form of human-induced rapid environmental changes (HIREC) and is strongly interfering with natural dark–light cycles. Some personality types within a species might be better suited to cope with environmental change and therefore might be selected upon under ongoing urbanization. Results: We used LED street lamps in a large outdoor enclosure to experimentally investigate the effects of ALAN on activity patterns, movement and interaction of individuals of two species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius). We analyzed effects combined with individual boldness score. Both species reduced their activity budget during daylight hours. While under natural light conditions home ranges were larger during daylight than during nighttime, this difference vanished under ALAN. Conspecifics showed reduced home range overlap, proximity and activity synchrony when subjected to nighttime illumination. Changes in movement patterns in reaction to ALAN were not associated with differences in boldness score of individuals. Conclusions: Our results suggest that light pollution can lead to changes in movement patterns and individual interactions in small mammals. This could lead to fitness consequences on the population level. KW - Nighttime illumination KW - Rodents KW - Outdoor enclosure KW - Animal personality KW - Interspecific interactions KW - HIREC Y1 - 2019 U6 - https://doi.org/10.1186/s12898-019-0241-0 SN - 1472-6785 VL - 19 PB - BioMed Central CY - London ER -