@article{EccardHerdeSchusteretal.2022,
  author    = {Eccard, Jana and Herde, Antje and Schuster, Andrea C. and Liesenjohann, Thilo and Knopp, Tatjana and Heckel, Gerald and Dammhahn, Melanie},
  title     = {Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations},
  series = {Ecology And Evolution},
  journal   = {Ecology And Evolution},
  publisher = {John Wiley \& Sons, Inc.},
  address   = {Vereinigte Staaten},
  issn      = {2045-7758},
  doi       = {10.1002/ece3.8521},
  pages     = {1 -- 15},
  year      = {2022},
  abstract  = {Individuals of a population may vary along a pace-of-life syndrome from highly fecund, short-lived, bold, dispersive "fast" types at one end of the spectrum to less fecund, long-lived, shy, plastic "slow" types at the other end. Risk-taking behavior might mediate the underlying life history trade-off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed-sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95\% and 50\% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex-boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near-natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter- and intra-annual fluctuations in population density in the study species and its short life span, density-dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace-of-life.},
  language  = {en}
}
@article{SchusterHerdeMazzonietal.2016,
  author    = {Schuster, Andrea C. and Herde, Antje and Mazzoni, Camila J. and Eccard, Jana and Sommer, Simone},
  title     = {Evidence for selection maintaining MHC diversity in a rodent species despite strong density fluctuations},
  series = {Immunogenetics},
  volume    = {68},
  journal   = {Immunogenetics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0093-7711},
  doi       = {10.1007/s00251-016-0916-z},
  pages     = {429 -- 437},
  year      = {2016},
  abstract  = {Strong spatiotemporal variation in population size often leads to reduced genetic diversity limiting the adaptive potential of individual populations. Key genes of adaptive variation are encoded by the immune genes of the major histocompatibility complex (MHC) playing an essential role in parasite resistance. How MHC variation persists in rodent populations that regularly experience population bottlenecks remains an important topic in evolutionary genetics. We analysed the consequences of strong population fluctuations on MHC class II DRB exon 2 diversity in two distant common vole (Microtus arvalis) populations in three consecutive years using a high-throughput sequencing approach. In 143 individuals, we detected 25 nucleotide alleles translating into 14 unique amino acid MHC alleles belonging to at least three loci. Thus, the overall allelic diversity and amino acid distance among the remaining MHC alleles, used as a surrogate for the range of pathogenic antigens that can be presented to T-cells, are still remarkably high. Both study populations did not show significant population differentiation between years, but significant differences were found between sites. We concluded that selection processes seem to be strong enough to maintain moderate levels of MHC diversity in our study populations outcompeting genetic drift, as the same MHC alleles were conserved between years. Differences in allele frequencies between populations might be the outcome of different local parasite pressures and/or genetic drift. Further understanding of how pathogens vary across space and time will be crucial to further elucidate the mechanisms maintaining MHC diversity in cyclic populations.},
  language  = {en}
}
@article{HerdeEccard2013,
  author    = {Herde, Antje and Eccard, Jana},
  title     = {Consistency in boldness, activity and exploration at different stages of life},
  series = {BMC ecology},
  volume    = {13},
  journal   = {BMC ecology},
  number    = {12},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1472-6785},
  doi       = {10.1186/1472-6785-13-49},
  pages     = {10},
  year      = {2013},
  abstract  = {Background: Animals show consistent individual behavioural patterns over time and over situations. This phenomenon has been referred to as animal personality or behavioural syndromes. Little is known about consistency of animal personalities over entire life times. We investigated the repeatability of behaviour in common voles (Microtus arvalis) at different life stages, with different time intervals, and in different situations. Animals were tested using four behavioural tests in three experimental groups: 1. before and after maturation over three months, 2. twice as adults during one week, and 3. twice as adult animals over three months, which resembles a substantial part of their entire adult life span of several months. Results: Different behaviours were correlated within and between tests and a cluster analysis showed three possible behavioural syndrome-axes, which we name boldness, exploration and activity. Activity and exploration behaviour in all tests was highly repeatable in adult animals tested over one week. In animals tested over maturation, exploration behaviour was consistent whereas activity was not. Voles that were tested as adults with a three-month interval showed the opposite pattern with stable activity but unstable exploration behaviour. Conclusions: The consistency in behaviour over time suggests that common voles do express stable personality over short time. Over longer periods however, behaviour is more flexible and depending on life stage (i.e. tested before/after maturation or as adults) of the tested individual. Level of boldness or activity does not differ between tested groups and maintenance of variation in behavioural traits can therefore not be explained by expected future assets as reported in other studies.},
  language  = {en}
}