@misc{VilkAghionAvgaretal.2022, author = {Vilk, Ohad and Aghion, Erez and Avgar, Tal and Beta, Carsten and Nagel, Oliver and Sabri, Adal and Sarfati, Raphael and Schwartz, Daniel K. and Weiß, Matthias and Krapf, Diego and Nathan, Ran and Metzler, Ralf and Assaf, Michael}, title = {Unravelling the origins of anomalous diffusion}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1303}, issn = {1866-8372}, doi = {10.25932/publishup-57764}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-577643}, pages = {16}, year = {2022}, abstract = {Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mean-squared displacement on the measurement time, is ubiquitous in nature. It has been observed in processes ranging from microscopic movement of molecules to macroscopic, large-scale paths of migrating birds. Using data from multiple empirical systems, spanning 12 orders of magnitude in length and 8 orders of magnitude in time, we employ a method to detect the individual underlying origins of anomalous diffusion and transport in the data. This method decomposes anomalous transport into three primary effects: long-range correlations ("Joseph effect"), fat-tailed probability density of increments ("Noah effect"), and nonstationarity ("Moses effect"). We show that such a decomposition of real-life data allows us to infer nontrivial behavioral predictions and to resolve open questions in the fields of single-particle tracking in living cells and movement ecology.}, language = {en} } @article{VilkAghionAvgaretal.2022, author = {Vilk, Ohad and Aghion, Erez and Avgar, Tal and Beta, Carsten and Nagel, Oliver and Sabri, Adal and Sarfati, Raphael and Schwartz, Daniel K. and Weiß, Matthias and Krapf, Diego and Nathan, Ran and Metzler, Ralf and Assaf, Michael}, title = {Unravelling the origins of anomalous diffusion}, series = {Physical review research / American Physical Society}, volume = {4}, journal = {Physical review research / American Physical Society}, number = {3}, publisher = {American Physical Society}, address = {College Park, MD}, issn = {2643-1564}, doi = {10.1103/PhysRevResearch.4.033055}, pages = {16}, year = {2022}, abstract = {Anomalous diffusion or, more generally, anomalous transport, with nonlinear dependence of the mean-squared displacement on the measurement time, is ubiquitous in nature. It has been observed in processes ranging from microscopic movement of molecules to macroscopic, large-scale paths of migrating birds. Using data from multiple empirical systems, spanning 12 orders of magnitude in length and 8 orders of magnitude in time, we employ a method to detect the individual underlying origins of anomalous diffusion and transport in the data. This method decomposes anomalous transport into three primary effects: long-range correlations ("Joseph effect"), fat-tailed probability density of increments ("Noah effect"), and nonstationarity ("Moses effect"). We show that such a decomposition of real-life data allows us to infer nontrivial behavioral predictions and to resolve open questions in the fields of single-particle tracking in living cells and movement ecology.}, language = {en} } @article{RoticsKaatzResheffetal.2016, author = {Rotics, Shay and Kaatz, Michael and Resheff, Yehezkel S. and Turjeman, Sondra Feldman and Zurell, Damaris and Sapir, Nir and Eggers, Ute and Flack, Andrea and Fiedler, Wolfgang and Jeltsch, Florian and Wikelski, Martin and Nathan, Ran}, title = {The challenges of the first migration: movement and behaviour of juvenile vs. adult white storks with insights regarding juvenile mortality}, series = {Journal of animal ecology : a journal of the British Ecological Society}, volume = {85}, journal = {Journal of animal ecology : a journal of the British Ecological Society}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0021-8790}, doi = {10.1111/1365-2656.12525}, pages = {938 -- 947}, year = {2016}, abstract = {1. Migration conveys an immense challenge, especially for juvenile birds coping with enduring and risky journeys shortly after fledging. Accordingly, juveniles exhibit considerably lower survival rates compared to adults, particularly during migration. Juvenile white storks (Ciconia ciconia), which are known to rely on adults during their first fall migration presumably for navigational purposes, also display much lower annual survival than adults. 2. Using detailed GPS and body acceleration data, we examined the patterns and potential causes of age-related differences in fall migration properties of white storks by comparing first-year juveniles and adults. We compared juvenile and adult parameters of movement, behaviour and energy expenditure (estimated from overall dynamic body acceleration) and placed this in the context of the juveniles' lower survival rate. 3. Juveniles used flapping flight vs. soaring flight 23\% more than adults and were estimated to expend 14\% more energy during flight. Juveniles did not compensate for their higher flight costs by increased refuelling or resting during migration. When juveniles and adults migrated together in the same flock, the juvenile flew mostly behind the adult and was left behind when they separated. Juveniles showed greater improvement in flight efficiency throughout migration compared to adults which appears crucial because juveniles exhibiting higher flight costs suffered increased mortality. 4. Our findings demonstrate the conflict between the juveniles' inferior flight skills and their urge to keep up with mixed adult-juvenile flocks. We suggest that increased flight costs are an important proximate cause of juvenile mortality in white storks and likely in other soaring migrants and that natural selection is operating on juvenile variation in flight efficiency.}, language = {en} } @misc{NathanHorvitzHeetal.2011, author = {Nathan, Ran and Horvitz, Nir and He, Yanping and Kuparinen, Anna and Schurr, Frank Martin and Katul, Gabriel G.}, title = {Spread of North American wind-dispersed trees in future environments}, series = {Ecology letters}, volume = {14}, journal = {Ecology letters}, number = {3}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {1461-023X}, doi = {10.1111/j.1461-0248.2010.01573.x}, pages = {211 -- 219}, year = {2011}, abstract = {P>Despite ample research, understanding plant spread and predicting their ability to track projected climate changes remain a formidable challenge to be confronted. We modelled the spread of North American wind-dispersed trees in current and future (c. 2060) conditions, accounting for variation in 10 key dispersal, demographic and environmental factors affecting population spread. Predicted spread rates vary substantially among 12 study species, primarily due to inter-specific variation in maturation age, fecundity and seed terminal velocity. Future spread is predicted to be faster if atmospheric CO2 enrichment would increase fecundity and advance maturation, irrespective of the projected changes in mean surface windspeed. Yet, for only a few species, predicted wind-driven spread will match future climate changes, conditioned on seed abscission occurring only in strong winds and environmental conditions favouring high survival of the farthest-dispersed seeds. Because such conditions are unlikely, North American wind-dispersed trees are expected to lag behind the projected climate range shift.}, language = {en} } @article{SchurrSteinitzNathan2008, author = {Schurr, Frank Martin and Steinitz, Ofer and Nathan, Ran}, title = {Plant fecundity and seed dispersal in spatially heterogeneous environments : models, mechanisms and estimation}, issn = {0022-0477}, doi = {10.1111/j.1365-2745.2008.01371.x}, year = {2008}, language = {en} } @article{VilkCamposMendezetal.2022, author = {Vilk, Ohad and Campos, Daniel and M{\´e}ndez, Vicen{\c{c}} and Lourie, Emmanuel and Nathan, Ran and Assaf, Michael}, title = {Phase transition in a non-Markovian animal exploration model with preferential returns}, series = {Physical review letters}, volume = {128}, journal = {Physical review letters}, number = {14}, publisher = {American Physical Society}, address = {College Park}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.128.148301}, pages = {7}, year = {2022}, abstract = {We study a non-Markovian and nonstationary model of animal mobility incorporating both exploration and memory in the form of preferential returns. Exact results for the probability of visiting a given number of sites are derived and a practical WKB approximation to treat the nonstationary problem is developed. A mean-field version of this model, first suggested by Song et al., [Modelling the scaling properties of human mobility, Nat. Phys. 6, 818 (2010)] was shown to well describe human movement data. We show that our generalized model adequately describes empirical movement data of Egyptian fruit bats (Rousettus aegyptiacus) when accounting for interindividual variation in the population. We also study the probability of visiting any site a given number of times and derive a mean-field equation. Our analysis yields a remarkable phase transition occurring at preferential returns which scale linearly with past visits. Following empirical evidence, we suggest that this phase transition reflects a trade-off between extensive and intensive foraging modes.}, language = {en} } @article{TuckerBoehningGaeseFaganetal.2018, author = {Tucker, Marlee A. and Boehning-Gaese, Katrin and Fagan, William F. and Fryxell, John M. and Van Moorter, Bram and Alberts, Susan C. and Ali, Abdullahi H. and Allen, Andrew M. and Attias, Nina and Avgar, Tal and Bartlam-Brooks, Hattie and Bayarbaatar, Buuveibaatar and Belant, Jerrold L. and Bertassoni, Alessandra and Beyer, Dean and Bidner, Laura and van Beest, Floris M. and Blake, Stephen and Blaum, Niels and Bracis, Chloe and Brown, Danielle and de Bruyn, P. J. Nico and Cagnacci, Francesca and Calabrese, Justin M. and Camilo-Alves, Constanca and Chamaille-Jammes, Simon and Chiaradia, Andre and Davidson, Sarah C. and Dennis, Todd and DeStefano, Stephen and Diefenbach, Duane and Douglas-Hamilton, Iain and Fennessy, Julian and Fichtel, Claudia and Fiedler, Wolfgang and Fischer, Christina and Fischhoff, Ilya and Fleming, Christen H. and Ford, Adam T. and Fritz, Susanne A. and Gehr, Benedikt and Goheen, Jacob R. and Gurarie, Eliezer and Hebblewhite, Mark and Heurich, Marco and Hewison, A. J. Mark and Hof, Christian and Hurme, Edward and Isbell, Lynne A. and Janssen, Rene and Jeltsch, Florian and Kaczensky, Petra and Kane, Adam and Kappeler, Peter M. and Kauffman, Matthew and Kays, Roland and Kimuyu, Duncan and Koch, Flavia and Kranstauber, Bart and LaPoint, Scott and Leimgruber, Peter and Linnell, John D. C. and Lopez-Lopez, Pascual and Markham, A. Catherine and Mattisson, Jenny and Medici, Emilia Patricia and Mellone, Ugo and Merrill, Evelyn and Mourao, Guilherme de Miranda and Morato, Ronaldo G. and Morellet, Nicolas and Morrison, Thomas A. and Diaz-Munoz, Samuel L. and Mysterud, Atle and Nandintsetseg, Dejid and Nathan, Ran and Niamir, Aidin and Odden, John and Oliveira-Santos, Luiz Gustavo R. and Olson, Kirk A. and Patterson, Bruce D. and de Paula, Rogerio Cunha and Pedrotti, Luca and Reineking, Bjorn and Rimmler, Martin and Rogers, Tracey L. and Rolandsen, Christer Moe and Rosenberry, Christopher S. and Rubenstein, Daniel I. and Safi, Kamran and Said, Sonia and Sapir, Nir and Sawyer, Hall and Schmidt, Niels Martin and Selva, Nuria and Sergiel, Agnieszka and Shiilegdamba, Enkhtuvshin and Silva, Joao Paulo and Singh, Navinder and Solberg, Erling J. and Spiegel, Orr and Strand, Olav and Sundaresan, Siva and Ullmann, Wiebke and Voigt, Ulrich and Wall, Jake and Wattles, David and Wikelski, Martin and Wilmers, Christopher C. and Wilson, John W. and Wittemyer, George and Zieba, Filip and Zwijacz-Kozica, Tomasz and Mueller, Thomas}, title = {Moving in the Anthropocene}, series = {Science}, volume = {359}, journal = {Science}, number = {6374}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aam9712}, pages = {466 -- 469}, year = {2018}, abstract = {Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission.}, language = {en} } @article{BuchmannSchurrNathanetal.2012, author = {Buchmann, Carsten M. and Schurr, Frank Martin and Nathan, Ran and Jeltsch, Florian}, title = {Movement upscaled - the importance of individual foraging movement for community response to habitat loss}, series = {Ecography : pattern and diversity in ecology ; research papers forum}, volume = {35}, journal = {Ecography : pattern and diversity in ecology ; research papers forum}, number = {5}, publisher = {Wiley-Blackwell}, address = {Malden}, issn = {0906-7590}, doi = {10.1111/j.1600-0587.2011.06924.x}, pages = {436 -- 445}, year = {2012}, abstract = {Habitat loss poses a severe threat to biodiversity. While many studies yield valuable information on how specific species cope with such environmental modification, the mechanistic understanding of how interacting species or whole communities are affected by habitat loss is still poor. Individual movement plays a crucial role for the space use characteristics of species, since it determines how individuals perceive and use their heterogeneous environment. At the community level, it is therefore essential to include individual movement and how it is influenced by resource sharing into the investigation of consequences of habitat loss. To elucidate the effects of foraging movement on communities in face of habitat loss, we here apply a recently published spatially-explicit and individual-based model of home range formation. This approach allows predicting the individual size distribution (ISD) of mammal communities in simulation landscapes that vary in the amount of suitable habitat. We apply three fundamentally different foraging movement approaches (central place forager (CPF), patrolling forager (PF) and body mass dependent nomadic forager (BNF)). Results show that the efficiency of the different foraging strategies depends on body mass, which again affects community structure in face of habitat loss. CPF is only efficient for small animals, and therefore yields steep ISD exponents on which habitat loss has little effect (due to a movement limitation of body mass). PF and particularly BNF are more efficient for larger animals, resulting in less steep ISDs with higher mass maxima, both showing a threshold behaviour with regard to loss of suitable habitat. These findings represent a new way of explaining observed extinction thresholds, and therefore indicate the importance of individual space use characterized by physiology and behaviour, i.e. foraging movement, for communities and their response to habitat loss. Findings also indicate the necessity to incorporate the crucial role of movement into future conservation efforts of terrestrial communities.}, language = {en} } @article{NathanSchurrSpiegeletal.2008, author = {Nathan, Ran and Schurr, Frank Martin and Spiegel, Orr and Steinitz, Ofer and Trakhtenbrot, Ana and Tsoar, Asaf}, title = {Mechanisms of long-distance seed dispersal}, issn = {0169-5347}, doi = {10.1016/j.tree.2008.08.003}, year = {2008}, abstract = {Growing recognition of the importance of long-distance dispersal (LDD) of plant seeds for various ecological and evolutionary processes has led to an upsurge of research into the mechanisms underlying LDD. We summarize these findings by formulating six generalizations stating that LDD is generally more common in open terrestrial landscapes, and is typically driven by large and migratory animals, extreme meteorological phenomena, ocean currents and human transportation, each transporting a variety of seed morphologies. LDD is often associated with unusual behavior of the standard vector inferred from plant dispersal morphology, or mediated by nonstandard vectors. To advance our understanding of LDD, we advocate a vector-based research approach that identifies the significant LDD vectors and quantifies how environmental conditions modify their actions.}, language = {en} } @article{ZurellEggersKaatzetal.2015, author = {Zurell, Damaris and Eggers, Ute and Kaatz, Michael and Rotics, Shay and Sapir, Nir and Wikelski, Martin and Nathan, Ran and Jeltsch, Florian}, title = {Individual-based modelling of resource competition to predict density-dependent population dynamics: a case study with white storks}, series = {Oikos}, volume = {124}, journal = {Oikos}, number = {3}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0030-1299}, doi = {10.1111/oik.01294}, pages = {319 -- 330}, year = {2015}, abstract = {Density regulation influences population dynamics through its effects on demographic rates and consequently constitutes a key mechanism explaining the response of organisms to environmental changes. Yet, it is difficult to establish the exact form of density dependence from empirical data. Here, we developed an individual-based model to explore how resource limitation and behavioural processes determine the spatial structure of white stork Ciconia ciconia populations and regulate reproductive rates. We found that the form of density dependence differed considerably between landscapes with the same overall resource availability and between home range selection strategies, highlighting the importance of fine-scale resource distribution in interaction with behaviour. In accordance with theories of density dependence, breeding output generally decreased with density but this effect was highly variable and strongly affected by optimal foraging strategy, resource detection probability and colonial behaviour. Moreover, our results uncovered an overlooked consequence of density dependence by showing that high early nestling mortality in storks, assumed to be the outcome of harsh weather, may actually result from density dependent effects on food provision. Our findings emphasize that accounting for interactive effects of individual behaviour and local environmental factors is crucial for understanding density-dependent processes within spatially structured populations. Enhanced understanding of the ways animal populations are regulated in general, and how habitat conditions and behaviour may dictate spatial population structure and demographic rates is critically needed for predicting the dynamics of populations, communities and ecosystems under changing environmental conditions.}, language = {en} }