@article{vanToorNewmanTakekawaetal.2016,
  author    = {van Toor, Mari{\"e}lle L. and Newman, Scott H. and Takekawa, John Y. and Wegmann, Martin and Safi, Kamran},
  title     = {Temporal segmentation of animal trajectories informed by habitat use},
  series = {Ecosphere},
  volume    = {7},
  journal   = {Ecosphere},
  number    = {10},
  doi       = {10.1002/ecs2.1498},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164970},
  pages     = {e01498},
  year      = {2016},
  abstract  = {Most animals live in seasonal environments and experience very different conditions throughout the year. Behavioral strategies like migration, hibernation, and a life cycle adapted to the local seasonality help to cope with fluctuations in environmental conditions. Thus, how an individual utilizes the environment depends both on the current availability of habitat and the behavioral prerequisites of the individual at that time. While the increasing availability and richness of animal movement data has facilitated the development of algorithms that classify behavior by movement geometry, changes in the environmental correlates of animal movement have so far not been exploited for a behavioral annotation. Here, we suggest a method that uses these changes in individual-environment associations to divide animal location data into segments of higher ecological coherence, which we term niche segmentation. We use time series of random forest models to evaluate the transferability of habitat use over time to cluster observational data accordingly. We show that our method is able to identify relevant changes in habitat use corresponding to both changes in the availability of habitat and how it was used using simulated data, and apply our method to a tracking data set of common teal (Anas crecca). The niche segmentation proved to be robust, and segmented habitat suitability outperformed models neglecting the temporal dynamics of habitat use. Overall, we show that it is possible to classify animal trajectories based on changes of habitat use similar to geometric segmentation algorithms. We conclude that such an environmentally informed classification of animal trajectories can provide new insights into an individuals' behavior and enables us to make sensible predictions of how suitable areas might be connected by movement in space and time.},
  language  = {en}
}
@article{BoddenRichterSchreiberetal.2015,
  author    = {Bodden, Carina and Richter, S. Helene and Schreiber, Rebecca S. and Kloke, Vanessa and Gerß, Joachim and Palme, Rupert and Lesch, Klaus-Peter and Lewejohann, Lars and Kaiser, Sylvia and Sachser, Norbert},
  title     = {Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype},
  series = {Frontiers in Behavioral Neuroscience},
  volume    = {9},
  journal   = {Frontiers in Behavioral Neuroscience},
  number    = {47},
  doi       = {10.3389/fnbeh.2015.00047},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143723},
  year      = {2015},
  abstract  = {Behavioral profiles are influenced by both positive and negative experiences as well as the genetic disposition. Traditionally, accumulating adversity over lifetime is considered to predict increased anxiety like behavior ("allostatic load"). The alternative "mismatch hypothesis" suggests increased levels of anxiety if the early environment differs from the later-life environment. Thus, there is a need for a whole-life history approach to gain a deeper understanding of how behavioral profiles are shaped. The aim of this study was to elucidate the effects of life history on the behavioral profile of mice varying in serotonin transporter (5-HIT) genotype, an established mouse model of increased anxiety-like behavior. For this purpose, mice grew up under either adverse or beneficial conditions during early phases of life. In adulthood, they were further subdivided so as to face a situation that either matched or mismatched the condition experienced so far, resulting in four different life histories. Subsequently, mice were tested for their anxiety-like and exploratory behavior. The main results were: (1) Life history profoundly modulated the behavioral profile. Surprisingly, mice that experienced early beneficial and later escapable adverse conditions showed less anxiety-like and more exploratory behavior compared to mice of other life histories. (2) Genotype significantly influenced the behavioral profile, with homozygous 5-HTT knockout mice displaying highest levels of anxiety-like and lowest levels of exploratory behavior. Our findings concerning life history indicate that the absence of adversity does not necessarily cause lower levels of anxiety than accumulating adversity. Rather, some adversity may be beneficial, particularly when following positive events. Altogether, we conclude that for an understanding of behavioral profiles, it is not sufficient to look at experiences during single phases of life, but the whole life history has to be considered.},
  language  = {en}
}
@article{GroezingerTheinFeldhaaretal.2014,
  author    = {Gr{\"o}zinger, Franziska and Thein, J{\"u}rgen and Feldhaar, Heike and R{\"o}del, Mark-Oliver},
  title     = {Giants, Dwarfs and the Environment - Metamorphic Trait Plasticity in the Common Frog},
  series = {PLOS ONE},
  volume    = {9},
  journal   = {PLOS ONE},
  number    = {3},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0089982},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117203},
  pages     = {e89982},
  year      = {2014},
  abstract  = {In order to understand adaptation processes and population dynamics, it is central to know how environmental parameters influence performance of organisms within populations, including their phenotypes. The impact of single or few particular parameters in concert was often assessed in laboratory and mesocosm experiments. However, under natural conditions, with many biotic and abiotic factors potentially interacting, outcomes on phenotypic changes may be different. To study the potential environmental impact on realized phenotypic plasticity within a natural population, we assessed metamorphic traits (developmental time, size and body mass) in an amphibian species, the European common frog Rana temporaria, since a) larval amphibians are known to exhibit high levels of phenotypic plasticity of these traits in response to habitat parameters and, b) the traits' features may strongly influence individuals' future performance and fitness. In 2007 we studied these metamorphic traits in 18 ponds spread over an area of 28 km 2. A subset of six ponds was reinvestigated in 2009 and 2010. This study revealed locally high variances in metamorphic traits in this presumed generalist species. We detected profound differences between metamorphing froglets (up to factor ten); both between and within ponds, on a very small geographic scale. Parameters such as predation and competition as well as many other pond characteristics, generally expected to have high impact on development, could not be related to the trait differences. We observed high divergence of patterns of mass at metamorphosis between ponds, but no detectable pattern when metamorphic traits were compared between ponds and years. Our results indicate that environment alone, i.e. as experienced by tadpoles sharing the same breeding pond, can only partly explain the variability of metamorphic traits observed. This emphasizes the importance to assess variability of reaction norms on the individual level to explain within-population variability.},
  language  = {en}
}