Arild Olsen Gautestad

• Gautestad, Arild O. (2022). Individual Network Topology of Patch Selection Under Influence of Drifting Site Fidelity. Frontiers in Ecology and Evolution. 10. doi: 10.3389/fevo.2022.695854. Full text in Research Archive Show summary

  Network theory has led to important insight into statistical-mechanical aspects of systems showing scaling complexity. I apply this approach to simulate the behavior of animal space use under the influence of memory and site fidelity. Based on the parsimonious Multi-scaled random walk model (MRW) an emergent property of self-reinforcing returns to a subset of historic locations shows how a network of nodes grows into an increased hierarchical depth of site fidelity. While most locations along a movement path may have a low revisit probability, habitat selection is maturing with respect to utilization of the most visited patches, in particular for patches that emerge during the early phase of node development. Using simulations with default MRW properties, which have been shown to produce space use in close statistical compliance with utilization distributions of many species of mammals, I illustrate how a shifting spatio-temporal mosaic of habitat utilization may be described statistically and given behavioral-ecological interpretation. The proposed method is illustrated with a pilot study using black bear Ursus americanus telemetry fixes. One specific parameter, the Characteristic Scale of Space Use, is here shown to express strong resilience against shifting site fidelity. This robust result may seem counter-intuitive, but is logical under the premise of the MRW model and its relationship to site fidelity, whether stable or shifting spatially over time. Thus, spatial analysis of the dynamics of a gradually drifting site fidelity using simulated scenarios may indirectly cast light on the dynamics of movement behavior as preferred patches are shifting over time. Both aspects of complex space use, network topology and dynamically drifting dispersion of site fidelity, provide in tandem important descriptors of behavioral ecology with relevance to habitat selection.

• Gautestad, Arild O. (2013). Animal space use: Distinguishing a two-level superposition of scale-specific walks from scale-free Lévy walk. Oikos. ISSN 0030-1299. 122(4), p. 612–620. doi: 10.1111/j.1600-0706.2012.19998.x. Full text in Research Archive
• Gautestad, Arild O. & Mysterud, Atle (2013). The Lévy flight foraging hypothesis: forgetting about memory may lead to false verification of Brownian motion. Movement Ecology. 1(9), p. 1–18. doi: 10.1186/2051-3933-1-9. Full text in Research Archive Show summary

  Background. The Lévy flight foraging hypothesis predicts a transition from scale-free Lévy walk (LW) to scale-specific Brownian motion (BM) as an animal moves from resource-poor towards resource-rich environment. However, the LW-BM continuum implies a premise of memory-less search, which contradicts the cognitive capacity of vertebrates. Results. We describe methods to test if apparent support for LW-BM transitions may rather be a statistical artifact from movement under varying intensity of site fidelity. A higher frequency of returns to previously visited patches (stronger site fidelity) may erroneously be interpreted as a switch from LW towards BM. Simulations of scale-free, memory-enhanced space use illustrate how the ratio between return events and scale-free exploratory movement translates to varying strength of site fidelity. An expanded analysis of GPS data of 18 female red deer, Cervus elaphus, strengthens previous empirical support of memory-enhanced and scale-free space use in a northern forest ecosystem. Conclusion. A statistical mechanical model architecture that describes foraging under environment-dependent variation of site fidelity may allow for higher realism of optimal search models and movement ecology in general, in particular for vertebrates with high cognitive capacity.

• Gautestad, Arild O.; Loe, Leif Egil & Mysterud, Atle (2013). Inferring spatial memory and spatiotemporal scaling from GPS data: comparing red deer Cervus ealphus movements with simulation models. Journal of Animal Ecology. ISSN 0021-8790. 82(3), p. 572–586. doi: 10.1111/1365-2656.12027. Full text in Research Archive
• Gautestad, Arild O. (2013). Lévy meets Poisson: A Statistical Artifact May Lead to Erroneous Recategorization of Lévy Walk as Brownian Motion. The American Naturalist. ISSN 0003-0147. 181(3), p. 440–450. doi: 10.1086/669148. Full text in Research Archive Show summary

  The flow of GPS data on animal space is challenging old paradigms, such as the issue of the scale-free Lévy walk versus scale-specific Brownian motion. Since these movement classes often require different protocols with respect to ecological analyses, further theoretical development in this field is important. I describe central concepts such as scale-specific versus scale-free movement and the difference between mechanistic and statistical-mechanical levels of analysis. Next, I report how a specific sampling scheme may have produced much confusion: a Lévy walk may be wrongly categorized as Brownian motion if the duration of a move, or bout, is used as a proxy for step length and a move is subjectively defined. Hence, the categorization and recategorization of movement class compliance surrounding the Lévy walk controversy may have been based on a statistical artifact. This issue may be avoided by collecting relocations at a fixed rate at a temporal scale that minimizes over- and undersampling. © 2013 University of Chicago Press

• Gautestad, Arild O. & Mysterud, Ivar (2012). The Dilution effect and the Space fill effect: Seeking to offset statistical artifacts when analyzing animal space use from telemetry fixes. Ecological Complexity : An International Journal on Biocomplexity in the Environment and Theoretical Ecology. ISSN 1476-945X. 9, p. 33–42. doi: 10.1016/j.ecocom.2011.11.005. Full text in Research Archive
• Gautestad, Arild O. (2012). Brownian motion or Lévy walk? Stepping towards an extended statistical mechanics for animal locomotion. Journal of the Royal Society Interface. ISSN 1742-5689. 9(74), p. 2332–2340. doi: 10.1098/rsif.2012.0059. Full text in Research Archive
• Gautestad, Arild O. (2011). Memory matters: Influence from a cognitive map on animal space use. Journal of Theoretical Biology. ISSN 0022-5193. 287, p. 26–36. doi: 10.1016/j.jtbi.2011.07.010. Full text in Research Archive
• Gautestad, Arild Olsen & Mysterud, Ivar (2010). The home range fractal: From random walk to memory-dependent space use. Ecological Complexity : An International Journal on Biocomplexity in the Environment and Theoretical Ecology. ISSN 1476-945X. 7, p. 458–470. doi: 10.1016/j.ecocom.2009.11.005. Full text in Research Archive
• Gautestad, Arild O. & Mysterud, Ivar (2010). Spatial memory, habitat auto-facilitation and the emergence of fractal home range patterns. Ecological Modelling. ISSN 0304-3800. 221(23), p. 2741–2750. doi: 10.1016/j.ecolmodel.2010.08.014. Full text in Research Archive
• Gautestad, Arild Olsen & Mysterud, Ivar (2006). Complex animal distribution and abundance from memony-dependent kinetics. Ecological Complexity : An International Journal on Biocomplexity in the Environment and Theoretical Ecology. ISSN 1476-945X. 3. Full text in Research Archive
• Gautestad, Arild O.; Wielgolaski, Frans Emil; Solberg, Birger & Mysterud, Ivar (2005). Scenarios for future development of the mountain birch ecosystem. In Wielgolaski, Frans Emil; Karlsson, P. Staffan; Neuvonen, Seppo & Thannheiser, Dietbert (Ed.), Plant Ecology, Herbivory, and Human Impact in Nordic Mountain Birch Forests. Springer. ISSN 9783540229094. p. 301–311. doi: 10.1007/3-540-26595-3_22. Full text in Research Archive
• Gautestad, Arild O.; Wielgolaski, F. E. & Mysterud, I. (2005). Landscape-scale model relating the nordic mountain birch forest spatio-temporal dynamics to various anthropogenic influences, herbivory and climate change. Ecological Studies. ISSN 0070-8356. 180, p. 283–300. Full text in Research Archive
• Wielgolaski, F. E.; Karlsson, P. S.; Neuvonen, S.; Thannheiser, D; Tømmervik, H. & Gautestad, Arild O. (2005). The Nordic mountain birch ecosystem – challenges to sustainable management. Ecological Studies. ISSN 0070-8356. 180, p. 343–356. Full text in Research Archive
• Gautestad, Arild Olsen & Mysterud, Ivar (2005). Intrinsic scaling complexity in animal dispersion and abundance. The American Naturalist. ISSN 0003-0147. 165. Full text in Research Archive
• Gautestad, Arild Olsen & Wielgolaski, Frans Emil (2001). Dynamic modeling of the mountain birch forest ecosystem: Challenges related to space, time and scale. Skogræktarritid. ISSN 1670-0074. 2001(01), p. 145–150. Full text in Research Archive

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• Gautestad, Arild O. (2015). Animal Space Use: Memory Effects, Scaling Complexity, and Biophysical Model Coherence. Dog ear publishing. ISBN 9781457541803. 336 p. Full text in Research Archive

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• Gautestad, Arild Olsen & Wielgolaski, Frans Emil (2002). The HIBECO model. Full text in Research Archive
• Wielgolaski, Frans Emil; Gautestad, Arild Olsen & Nordland, Arve (2001). Åkerkant, løvskog, ferskvann og myr. Full text in Research Archive Show summary

  Planter og dyr i økologisk sammenheng i økotonen åkerkant, i løvskog (særlig tørr og fuktig edelløvskog), i eutroft-mesotroft og i dystroft ferskvann og i gjengroingsmyr

• Wielgolaski, Frans Emil; Gautestad, Arild Olsen & Nordland, Arve (2001). Barskog og fjellbjørkeskog. Full text in Research Archive Show summary

  Planter og dyr i økologisk sammenheng i ulike typer av granskog og furuskog og i fjellbjørkeskog med Østlandet som eksempel

• Wielgolaski, Frans Emil; Gautestad, Arild Olsen & Nordland, Arve (2001). Snaufjellet. Full text in Research Archive Show summary

  Planter og dyr i økologisk sammenheng langs gradienter i lavalpin og mellom-høyalpin region

• Wielgolaski, Frans Emil; Gautestad, Arild Olsen & Nordland, Arve (2001). Havstrand. Full text in Research Archive Show summary

  Ytre Oslofjord er brukt som eksempel for botanikk og zoologi på klippestrand, eksponert og beskyttet strand

• Gautestad, Arild Olsen & Wielgolaski, Frans Emil (2001). Internet-based collaboration under the HIBECO project: Human interactions with the mountain birch forest ecosystem. Full text in Research Archive
• Wielgolaski, Frans Emil & Gautestad, Arild Olsen (2001). The HIBECO model - in the Integration workshop. Full text in Research Archive

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