Virtual Issue: Movement Ecology

 

Photo credit: Riccardo Del Guerra

 When the ecologist Charles Sutherland Elton (1900-1991) developed the field of Animal Ecology (1927; 1933) and proposed the Journal of Animal Ecology in 1931 (see Animal Ecology - Legacy of Charles S Elton, Virtual Issue 2011), he stressed the necessity for the field to distinguish itself from the approaches used by plant ecologists, due to the different principles governing animal systems, most notably as ‘animals move about’ (Elton 1933). Since then the study of the causes and consequences of movement of organisms has become a central question in ecology, providing a link between individual behaviour and spatial processes, from population to community ecology and beyond.

More recently there has been an attempt to provide a conceptual unification of the wide and somewhat disparate field of movement studies, under the Movement Ecology framework (or paradigm, see Nathan et al. 2008 PNAS). The underlying idea of the framework is that the geometry of any movement path is given by the combined effect of four main mechanistic components, namely that the decision of when and how to move is determined by the interactions between the individual organism (internal state, individual conditions) and the external environment (abiotic and biotic), conditional on the movement and orientation capacities of the organism. Thus different frameworks, from empirical to methodological to theoretical, can be accommodated under this unifying paradigm. Hence, whilst individual studies may focus on different mechanistic causes of movement, such as the internal state (why move?) or the navigation process (where to move?), the interpretation and generalisation of the inferences obtained is facilitated by the unifying interpretative framework.

Journal of Animal Ecology has been at the forefront of animal movement research, including novel technological and methodological developments which are fuelling the strong developments in the field (see Biotelemetry and Biologging, Virtual Issue 2008), and a growing number of publications specifically focussed on the ‘Movement Ecology’ paradigm. In rapidly growing fields, fuelled by technological and methodological advancements, a divide can form between the developments of new tools and the research questions addressed, with the former taking the centre stage. Accordingly, in the current Issue the Journal has published a Movement Ecology Special Feature, guest edited by Bram van Moorter, Manuela Panzacchi, Francesca Cagnacci and Mark S. Boyce, aimed at addressing this disconnect and provide examples of how to connect ‘tools’ with the research questions (Borger 2016).

This Virtual Issue has been compiled to coincide with the Movement Ecology Special Feature and is aimed at complementing it by reflecting recent exciting developments in the field, covered by papers in the Journal. Among the four mechanistic components of the Movement Ecology paradigm, understanding the effects of the external environment is certainly of paramount importance under current global change scenarios. Movement is one of the first behavioural responses of animals to environmental change and Senner et al. investigated the movement and fitness consequences of an extreme weather event for a long-distance migratory bird. Given that extreme weather events are expected to increase, under current climate change predictions, it is timely to see that such events may not constitute a great challenge for populations with large behavioural plasticity, continued access to food and no strict time constraints, as many populations might in reality be constrained by one of these aspects.

Orben et al. in fact show in another migratory diving seabird species how even an impressive behavioural flexibility in responding to local conditions may not be sufficient to adjust to changing environmental conditions, when constraints on movement capacity (here, expressed through body size) act differently between movement phases (small scale foraging vs. large scale migration), thereby restricting the set of available movement strategies. Diving capacity is a key movement capacity for seabirds, determining the functional relationship between environmental conditions and species distributions, yet studies with data on both prey and predator distributions are rare for seabirds, due to the difficulty of monitoring both; even less with concurrent data on foraging movements of individuals. Boyd et al. present data on the foraging movements of two surface-diving seabirds with different foraging modes (plunge vs. pursuit divers), combined with concurrent data on the abundance and depth distribution of the primary fish prey. Using this unique dataset the authors show that oceanographic processes determining the accessibility (depth distribution) of prey may be more important for surface foragers than those determining the overall abundance, with direct implications for marine reserve design.

Identifying the decision rules of foragers living in environments with complex spatio-temporal patterns of resource availability is of key interest also in terrestrial environments. Plante et al. present a new modelling framework to investigate how foraging movements are affected by internal state (hunger), resource preferences and the spatio-temporal distribution of the latter, and exemplify it on data on a neotropical primate. Cognitive capacities are expected to be of importance for animals to efficiently navigate in the environment and use the resources and Avgar et al. present evidence on the use of long-term spatial memory in caribou foraging movements, in relation to the distribution of forage abundance and predator and interspecific competitors.

Excluding competitors (‘territoriality’) is a widespread space use strategy among animals but for gregarious species, such as territorial carnivores, variations in the local density of individuals may be caused by changes in territory size or group size. Kittle et al. use a new statistical framework, showing that in wolves pack size may not vary with habitat quality and that instead individuals modify territory size in relation to local habitat quality. Bateman et al. present a new mathematical framework (‘mechanistic models’), applied to data on meerkats, to test the contribution of different processes, such as individual and group movement rules, territorial interactions with neighbouring groups and habitat quality, to dynamic changes in the development, distribution and size of territories. The presence and density of conspecifics may affect non-linearly the movements of organisms and Fronhofer et al. show evidence of an Allee effect in movement responses of a Protist to conspecific density. On the other hand, individual state is a key mechanistic component of the movement ecology framework and Godsall et al. present rarely available data on how the physiological state (energy reserves, body mass and androgenisation) and sex of an individual determines its movements and space use.

Movement capacity and propensity are also a fundamental mechanistic component in the movement ecology framework. Dahirel et al. present interesting data from European land snails confirming the expectation that habitat specialists disperse less than generalists and further show that this is associated with both lower movement capacity and propensity, with slower and more tortuous movements. Movement capacity is a key component especially for flying animals, determining where animals can forage efficiently depending on their aerodynamic performance and Cespedes et al. present an interesting study on the evolution of wing shape in Neotropical butterflies in relation to habitat-specific flight requirements. Moving in the aerial environment requires the ability to respond to the flow of the medium, maximizing the energy benefits that can be obtained from air currents and minimizing the negative impediments. Chapman et al. used radar data on a nocturnal noctuid moth and songbirds, showing contrasting yet adaptive flight strategies, in relation to the relative speed of the air flow and the individual.

Movement decisions also have demographic consequences and Bentley et al. show how adult sockeye salmon dynamically adjust diurnal and seasonal movements during the reproductive period to maximize access to the spawning areas whilst reducing the chance to encounter their main predator, the brown bear. Understanding when and where animals die is of fundamental importance for ecological studies, but such data are not easy to obtain. Using long-term tracking data on a migratory raptor Klaasen et al. show very interesting data on the spatio-temporal distribution of death events along the annual cycle, including both the stationary and migratory movement phases. How individuals move may also affect how they perceive habitat fragmentation and Cattarino et al. use a spatially explicit demographic model to understand how fragmentation at different scales affects the survival and reproduction of individuals moving with different strategies (frequencies of switch between movement modes).

Quantifying the scales of movements of individuals and populations is crucial for understanding and predicting the spread of zoonotic diseases, but Byrne et al. show that even in a well-studies species like the European badger that most studies are designed at too small scales to detect and quantify long-distance dispersal movements. Hall et al. show how seasonal migration can lead to lower infection risk through two different and non-exclusive mechanisms. Finally, dispersal fundamentally affects community composition and the rate of distance decay of community similarity and Karna et al. show the importance of obtaining more biologically realistic measures of the ‘cost distance’ of dispersal for stream insect communities.

Luca Börger
Associate Editor, Journal of Animal Ecology

When Siberia came to the Netherlands: the response of continental black-tailed godwits to a rare spring weather event
Nathan R. Senner, Mo A. Verhoeven, José M. Abad-Gómez et al.

Body size affects individual winter foraging strategies of thick-billed murres in the Bering Sea
Rachael A. Orben, Rosana Paredes, Daniel D. Roby, David B. Irons and Scott A. Shaffer

Predictive modelling of habitat selection by marine predators with respect to the abundance and depth distribution of pelagic prey
Charlotte Boyd, Ramiro Castillo, George L. Hunt Jr, André E. Punt, Glenn R. VanBlaricom, Henri Weimerskirch and Sophie Bertrand

Foraging strategy of a neotropical primate: how intrinsic and extrinsic factors influence destination and residence time
Sabrina Plante, Fernando Colchero and Sophie Calmé

Space-use behaviour of woodland caribou based on a cognitive movement model
Tal Avgar, James A. Baker, Glen S. Brown et al.

Wolves adapt territory size, not pack size to local habitat quality
Andrew M. Kittle, Morgan Anderson, Tal Avgar, et al.

Territoriality and home-range dynamics in meerkats, Suricata suricatta: a mechanistic modelling approach
Andrew W. Bateman, Mark A. Lewis, Gabriella Gal, Marta B. Manser and Tim H. Clutton-Brock

Density-dependent movement and the consequences of the Allee effect in the model organism Tetrahymena
Emanuel A. Fronhofer, Tabea Kropf and Florian Altermatt

From physiology to space use: energy reserves and androgenization explain home-range size variation in a woodland rodent
Ben Godsall, Tim Coulson andAurelio F. Malo

Movement propensity and ability correlate with ecological specialization in European land snails: comparative analysis of a dispersal syndrome
Maxime Dahirel, Eric Olivier, Annie Guiller, Marie-Claire Martin, Luc Madec and Armelle Ansart

Cruising the rain forest floor: butterfly wing shape evolution and gliding in ground effect
Ann Cespedes, Carla M. Penz and Philip J. DeVries

Adaptive strategies in nocturnally migrating insects and songbirds: contrasting responses to wind
Jason W. Chapman, Cecilia Nilsson, Ka S. Lim, Johan Bäckman, Don R. Reynolds and Thomas Alerstam

Predator avoidance during reproduction: diel movements by spawning sockeye salmon between stream and lake habitats
Kale T. Bentley, Daniel E. Schindler, Timothy J. Cline, Jonathan B. Armstrong, Daniel Macias, Lindsy R. Ciepiela and Ray Hilborn

When and where does mortality occur in migratory birds? Direct evidence from long- term satellite tracking of raptors
Raymond H. G. Klaassen, Mikael Hake, Roine Strandberg et al.

Spatial scale and movement behaviour traits control the impacts of habitat fragmentation on individual fitness
Cattarino, Clive A. McAlpine and Jonathan R. Rhodes

Large-scale movements in European badgers: has the tail of the movement kernel been underestimated?
Andrew W. Byrne, John L. Quinn, James J. O'Keeffe, Stuart Green, D. Paddy Sleeman, S. Wayne Martin and John Davenport

Greater migratory propensity in hosts lowers pathogen transmission and impacts
Richard J. Hall, Sonia Altizer and Rebecca A. Bartel

Inferring the effects of potential dispersal routes on the metacommunity structure of stream insects: as the crow flies, as the fish swims or as the fox runs?
Olli-Matti Kärnä, Mira Grönroos, Harri Antikainen, Jan Hjort, Jari Ilmonen, Lauri Paasivirta and Jani Heino

Additional Resources
Börger, L. (2016) EDITORIAL: Stuck in motion? Reconnecting questions and tools in movement ecology. Journal of Animal Ecology 85: 5–10.

Elton, C (1933) The ecology of animals. London: Methuen.

Nathan, R., Getz, W. M., Revilla, E., Holyoak, M., Kadmon, R., Saltz, D., & Smouse, P. E. (2008) A movement ecology paradigm for unifying organismal movement research. Proceedings of the National Academy of Sciences 105(49) 19052-19059.
 

Search the Site

Search

Site Adverts

  Demography Behind the Population2015 Elton PrizeDemography Beyond the Population Special Feature.Movement Ecology Virtual Issue. Photo credit: Riccardo Del GuerraStuck in Motion