@article{SchenkMitesserHovestadtetal.2018,
  author    = {Schenk, Mariela and Mitesser, Oliver and Hovestadt, Thomas and Holzschuh, Andrea},
  title     = {Overwintering temperature and body condition shift emergence dates of spring-emerging solitary bees},
  series = {PeerJ},
  volume    = {6},
  journal   = {PeerJ},
  doi       = {10.7717/peerj.4721},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228544},
  pages     = {e4721, 1-17},
  year      = {2018},
  abstract  = {Solitary bees in seasonal environments must align their life-cycles with favorable environmental conditions and resources; the timing of their emergence is highly fitness relevant. In several bee species, overwintering temperature influences both emergence date and body weight at emergence. High variability in emergence dates among specimens overwintering at the same temperatures suggests that the timing of emergence also depends on individual body conditions. However, possible causes for this variability, such as individual differences in body size or weight, have been rarely studied. In a climate chamber experiment using two spring-emerging mason bees (Osmia cornuta and O. bicornis), we investigated the relationship between temperature, emergence date, body weight, and body size, the last of which is not affected by overwintering temperature. Our study showed that body weight declined during hibernation more strongly in warm than in cold overwintering temperatures. Although bees emerged earlier in warm than in cold overwintering temperatures, at the time of emergence, bees in warm overwintering temperatures had lower body weights than bees in cold overwintering temperatures (exception of male O. cornuta). Among specimens that experienced the same overwintering temperatures, small and light bees emerged later than their larger and heavier conspecifics. Using a simple mechanistic model we demonstrated that spring-emerging solitary bees use a strategic approach and emerge at a date that is most promising for their individual fitness expectations. Our results suggest that warmer overwintering temperatures reduce bee fitness by causing a decrease in body weight at emergence. We showed furthermore that in order to adjust their emergence dates, bees use not only temperature but also their individual body condition as triggers. This may explain differing responses to climate warming within and among bee populations and may have consequences for bee-plant interactions as well as for the persistence of bee populations under climate change.},
  language  = {en}
}
@article{LineBarkusCoyleetal.2011,
  author    = {Line, Samantha J. and Barkus, Christopher and Coyle, Clare and Jennings, Katie A. and Deacon, Robert M. and Lesch, Klaus P. and Sharp, Trevor and Bannerman, David M.},
  title     = {Opposing alterations in anxiety and species-typical behaviours in serotonin transporter overexpressor and knockout mice},
  series = {European Neuropsychopharmacology},
  volume    = {21},
  journal   = {European Neuropsychopharmacology},
  number    = {1},
  doi       = {10.1016/j.euroneuro.2010.08.005},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141222},
  pages     = {108-116},
  year      = {2011},
  abstract  = {Human gene association studies have produced conflicting findings regarding the relationship between the 5-HT transporter (5-HTT) and anxiety. In the present study genetically modified mice were utilised to examine the effects of changes in 5-HTT expression on anxiety. In addition, the influence of 5-HTT expression on two innate "species-typical" behaviours (burrowing and marble burying) and body weight was explored. Across a range of models, 5-HTT overexpressing mice displayed reduced anxiety-like behaviour whilst 5-HTT knockout mice showed increased anxiety-like behaviour, compared to wildtype controls. In tests of species-typical behaviour 5-HTT overexpressing mice showed some facilitation whilst 5-HTT knockout mice were impaired. Reciprocal effects were also seen on body weight, as 5-HTT overexpressors were lighter and 5-HTT knockouts were heavier than wildtype controls. These findings show that variation in 5-HTT gene expression produces robust changes in anxiety and species-typical behaviour. Furthermore, the data add further support to findings that variation of 5-HTT expression in the human population is linked to changes in anxiety-related personality traits.},
  language  = {en}
}