Movement EcologyPub Date : 2024-09-24DOI: 10.1186/s40462-024-00500-x
William K Oestreich, Kelly J Benoit-Bird, Briana Abrahms, Tetyana Margolina, John E Joseph, Yanwu Zhang, Carlos A Rueda, John P Ryan
{"title":"Evidence for seasonal migration by a cryptic top predator of the deep sea.","authors":"William K Oestreich, Kelly J Benoit-Bird, Briana Abrahms, Tetyana Margolina, John E Joseph, Yanwu Zhang, Carlos A Rueda, John P Ryan","doi":"10.1186/s40462-024-00500-x","DOIUrl":"10.1186/s40462-024-00500-x","url":null,"abstract":"<p><strong>Background: </strong>In ecosystems influenced by strong seasonal variation in insolation, the fitness of diverse taxa depends on seasonal movements to track resources along latitudinal or elevational gradients. Deep pelagic ecosystems, where sunlight is extremely limited, represent Earth's largest habitable space and yet ecosystem phenology and effective animal movement strategies in these systems are little understood. Sperm whales (Physeter macrocephalus) provide a valuable acoustic window into this world: the echolocation clicks they produce while foraging in the deep sea are the loudest known biological sounds on Earth and convey detailed information about their behavior.</p><p><strong>Methods: </strong>We analyze seven years of continuous passive acoustic observations from the Central California Current System, using automated methods to identify both presence and demographic information from sperm whale echolocation clicks. By integrating empirical results with individual-level movement simulations, we test hypotheses about the movement strategies underlying sperm whales' long-distance movements in the Northeast Pacific.</p><p><strong>Results: </strong>We detect foraging sperm whales of all demographic groups year-round in the Central California Current System, but also identify significant seasonality in frequency of presence. Among several previously hypothesized movement strategies for this population, empirical acoustic observations most closely match simulated results from a population undertaking a \"seasonal resource-tracking migration\", in which individuals move to track moderate seasonal-latitudinal variation in resource availability.</p><p><strong>Discussion: </strong>Our findings provide evidence for seasonal movements in this cryptic top predator of the deep sea. We posit that these seasonal movements are likely driven by tracking of deep-sea resources, based on several lines of evidence: (1) seasonal-latitudinal patterns in foraging sperm whale detection across the Northeast Pacific; (2) lack of demographic variation in seasonality of presence; and (3) the match between simulations of seasonal resource-tracking migration and empirical results. We show that sperm whales likely track oceanographic seasonality in a manner similar to many surface ocean predators, but with dampened seasonal-latitudinal movement patterns. These findings shed light on the drivers of sperm whales' long-distance movements and the shrouded phenology of the deep-sea ecosystems in which they forage.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"65"},"PeriodicalIF":3.4,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11421108/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142309141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-23DOI: 10.1186/s40462-024-00506-5
Lukas Graf, Henrik Thurfjell, Göran Ericsson, Wiebke Neumann
{"title":"Naivety dies with the calf: calf loss to human hunters imposes behavioral change in a long-lived but heavily harvested ungulate.","authors":"Lukas Graf, Henrik Thurfjell, Göran Ericsson, Wiebke Neumann","doi":"10.1186/s40462-024-00506-5","DOIUrl":"10.1186/s40462-024-00506-5","url":null,"abstract":"<p><strong>Background: </strong>In prey, patterns of individual habitat selection and movement can be a consequence of an individuals' anti-predator behavior. Adjustments of anti-predator behavior are important for prey to increase their survival. Hunters may alter the anti-predator behavior of prey. In long-lived animals, experience may cause behavioral changes during individuals' lifetime, which may result in altered habitat selection and movement. Our knowledge of which specific events related to hunting activity induce behavioral changes in solitary living species is still limited.</p><p><strong>Methods: </strong>We used offspring loss in a solitary and long-lived ungulate species, moose (Alces alces), as our model system. We investigated whether offspring loss to hunters induces behavioral changes in a species subjected to heavy human harvest but free from natural predation. To test for behavioral change in relation to two proxies for experience (calf fate and age), we combined movement data from 51 adult female moose with data on their offspring survival and female age. We tested for adjustments in females' habitat selection and movement following calf harvest using Hidden Markov Models and integrated Step Selection Analysis to obtain behavioral state specific habitat selection coefficients.</p><p><strong>Results: </strong>We found that females with a harvested calf modified habitat selection and movement during the following hunting season. Female moose selected for shorter distance to roads during the night, selected for shorter distance to forests and greater distance to human settlements following calf harvest than females who had not lost a calf. The survival of twins in a given hunting season was related to female age. Older females we more likely to have twins survive the hunting season.</p><p><strong>Conclusions: </strong>Our findings suggest that losing offspring to human harvest imposes behavioral changes in a long-lived ungulate species, leading to adjustments in females' habitat selection and movement behavior, which may lower the risk of encountering hunters. In our study, female moose that experienced calf loss selected for lower distance to forest and selected for greater distance to human settlements during periods of high hunting pressure compared to females without the experience of calf loss during the previous hunting season. We interpret this as potential learning effects.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"66"},"PeriodicalIF":3.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11421125/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142309142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-12DOI: 10.1186/s40462-024-00504-7
William E. Brooks
{"title":"Offshore vagrancy in passerines is predicted by season, wind-drift, and species characteristics","authors":"William E. Brooks","doi":"10.1186/s40462-024-00504-7","DOIUrl":"https://doi.org/10.1186/s40462-024-00504-7","url":null,"abstract":"Migratory birds accomplish remarkable feats of long-distance navigation. Vagrants, few individuals who migrate to incorrect locations, reveal conditions where orientation and navigation fail. Studies of vagrancy on a continental scale reveal the importance of external factors such as strong winds driving birds off course, clouds obscuring migratory landmarks, and natural disruptions in the Earth’s magnetic field interfering with migratory orientation. Species may also possess characteristics that make them more prone to vagrancy. The external drivers of vagrancy on a smaller scale are less understood. I used eBird, a community science dataset comprising millions of bird observations, to study land passerines observed over the Pacific Ocean, here termed offshore vagrants. These data present the opportunity to study a particular case of vagrancy: small-scale displacement into highly inhospitable areas. I modeled how season, wind, lack of visibility, interference with magnetoreception, and species differences may predict offshore vagrancy. Then, I modeled how species vagrancy likelihood is predicted by morphological and life history traits. Vagrancy was more common in the fall and positively associated with stronger tail winds in the spring. Species with greater preference for understory foraging habitat were less likely to occur as vagrants. Species vagrancy likelihood was higher in birds with a longer migration distance and rounded wings, but the relationship was weaker in birds with a pointed wings. Brown-headed Cowbirds were the most common offshore species in terms of absolute number of records and proportional to onshore frequency. Offshore community science records proved revealing of mechanisms for small scale vagrancy in passerines. Offshore vagrancy can be driven by wind drift in the spring, but not in the fall despite higher overall levels of vagrancy. Life history characteristics like foraging habitat preference and migration duration may make some species more vulnerable to the effects of wind drift. Species with longer migrations may have more time to encounter vagrancy causing events, but greater aerodynamic efficiency may counteract this effect.","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"74 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Combined effects of landscape fragmentation and sampling frequency of movement data on the assessment of landscape connectivity","authors":"Marie-Caroline Prima, Mathieu Garel, Pascal Marchand, James Redcliffe, Luca Börger, Florian Barnier","doi":"10.1186/s40462-024-00492-8","DOIUrl":"https://doi.org/10.1186/s40462-024-00492-8","url":null,"abstract":"Network theory is largely applied in real-world systems to assess landscape connectivity using empirical or theoretical networks. Empirical networks are usually built from discontinuous individual movement trajectories without knowing the effect of relocation frequency on the assessment of landscape connectivity while theoretical networks generally rely on simple movement rules. We investigated the combined effects of relocation sampling frequency and landscape fragmentation on the assessment of landscape connectivity using simulated trajectories and empirical high-resolution (1 Hz) trajectories of Alpine ibex (Capra ibex). We also quantified the capacity of commonly used theoretical networks to accurately predict landscape connectivity from multiple movement processes. We simulated forager trajectories from continuous correlated biased random walks in simulated landscapes with three levels of landscape fragmentation. High-resolution ibex trajectories were reconstructed using GPS-enabled multi-sensor biologging data and the dead-reckoning technique. For both simulated and empirical trajectories, we generated spatial networks from regularly resampled trajectories and assessed changes in their topology and information loss depending on the resampling frequency and landscape fragmentation. We finally built commonly used theoretical networks in the same landscapes and compared their predictions to actual connectivity. We demonstrated that an accurate assessment of landscape connectivity can be severely hampered (e.g., up to 66% of undetected visited patches and 29% of spurious links) when the relocation frequency is too coarse compared to the temporal dynamics of animal movement. However, the level of landscape fragmentation and underlying movement processes can both mitigate the effect of relocation sampling frequency. We also showed that network topologies emerging from different movement behaviours and a wide range of landscape fragmentation were complex, and that commonly used theoretical networks accurately predicted only 30–50% of landscape connectivity in such environments. Very high-resolution trajectories were generally necessary to accurately identify complex network topologies and avoid the generation of spurious information on landscape connectivity. New technologies providing such high-resolution datasets over long periods should thus grow in the movement ecology sphere. In addition, commonly used theoretical models should be applied with caution to the study of landscape connectivity in real-world systems as they did not perform well as predictive tools.","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"13 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-06DOI: 10.1186/s40462-024-00498-2
C Antonia Klöcker, Ole Thomas Albert, Keno Ferter, Otte Bjelland, Robert J Lennox, Jon Albretsen, Lotte Pohl, Lotte Svengård Dahlmo, Nuno Queiroz, Claudia Junge
{"title":"Seasonal habitat use and diel vertical migration in female spurdog in Nordic waters.","authors":"C Antonia Klöcker, Ole Thomas Albert, Keno Ferter, Otte Bjelland, Robert J Lennox, Jon Albretsen, Lotte Pohl, Lotte Svengård Dahlmo, Nuno Queiroz, Claudia Junge","doi":"10.1186/s40462-024-00498-2","DOIUrl":"10.1186/s40462-024-00498-2","url":null,"abstract":"<p><strong>Background: </strong>Studying habitat use and vertical movement patterns of individual fish over continuous time and space is innately challenging and has therefore largely remained elusive for a wide range of species. Amongst sharks, this applies particularly to smaller-bodied and less wide-ranging species such as the spurdog (Squalus acanthias Linnaeus, 1758), which, despite its importance for fisheries, has received limited attention in biologging and biotelemetry studies, particularly in the North-East Atlantic.</p><p><strong>Methods: </strong>To investigate seasonal variations in fine-scale niche use and vertical movement patterns in female spurdog, we used archival data from 19 pregnant individuals that were satellite-tagged for up to 365 days in Norwegian fjords. We estimated the realised niche space with kernel densities and performed continuous wavelet analyses to identify dominant periods in vertical movement. Triaxial acceleration data were used to identify burst events and infer activity patterns.</p><p><strong>Results: </strong>Pregnant females frequently utilised shallow depths down to 300 m at temperatures between 8 and 14 °C. Oscillatory vertical moments revealed persistent diel vertical migration (DVM) patterns, with descents at dawn and ascents at dusk. This strict normal DVM behaviour dominated in winter and spring and was associated with higher levels of activity bursts, while in summer and autumn sharks predominantly selected warm waters above the thermocline with only sporadic dive and bursts events.</p><p><strong>Conclusions: </strong>The prevalence of normal DVM behaviour in winter months linked with elevated likely foraging-related activity bursts suggests this movement behaviour to be foraging-driven. With lower number of fast starts exhibited in warm waters during the summer and autumn months, habitat use in this season might be rather driven by behavioural thermoregulation, yet other factors may also play a role. Individual and cohort-related variations indicate a complex interplay of movement behaviour and habitat use with the abiotic and biotic environment. Together with ongoing work investigating fine-scale horizontal movement as well as sex- and age-specific differences, this study provides vital information to direct the spatio-temporal distribution of a newly reopened fishery and contributes to an elevated understanding of the movement ecology of spurdog in the North-East Atlantic and beyond.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"62"},"PeriodicalIF":3.4,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11380420/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142146872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-05DOI: 10.1186/s40462-024-00502-9
Quinn Webber, Christina Prokopenko, Katrien Kingdon, Julie Turner, Eric Vander Wal
{"title":"Effects of the social environment on movement-integrated habitat selection.","authors":"Quinn Webber, Christina Prokopenko, Katrien Kingdon, Julie Turner, Eric Vander Wal","doi":"10.1186/s40462-024-00502-9","DOIUrl":"10.1186/s40462-024-00502-9","url":null,"abstract":"<p><strong>Background: </strong>Movement links the distribution of habitats with the social environment of animals using those habitats. Despite the links between movement, habitat selection, and socioecology, their integration remains a challenge due to lack of shared vocabulary across fields, methodological gaps, and the implicit (rather than explicit) historical development of theory in the fields of social and spatial ecology. Given these challenges can be addressed, opportunity for further study will provide insight about the links between social, spatial, and movement ecology. Here, our objective was to disentangle the roles of habitat selection and social association as drivers of movement in caribou (Rangifer tarandus).</p><p><strong>Methods: </strong>To accomplish our objective, we modelled the relationship between collective movement and selection of foraging habitats using socially informed integrated step selection function (iSSF). Using iSSF, we modelled the effect of social processes, i.e., nearest neighbour distance and social preference, and movement behaviour on patterns of habitat selection.</p><p><strong>Results: </strong>By unifying social network analysis with iSSF, we identified movement-dependent social association, where individuals took shorter steps in lichen habitat and foraged in close proximity to more familiar individuals.</p><p><strong>Conclusions: </strong>Our study demonstrates that social preference is context-dependent based on habitat selection and foraging behaviour. We therefore surmise that habitat selection and social association are drivers of collective movement, such that movement is the glue between habitat selection and social association. Here, we put these concepts into practice to demonstrate that movement is the glue connecting individual habitat selection to the social environment.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"61"},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11378598/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142141669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-02DOI: 10.1186/s40462-024-00497-3
Holly R W Pickett, Robert A Robinson, Robert L Nudds
{"title":"Differential changes in the morphology and fuel loads of obligatory and partial migrant passerines over half a century in Britain.","authors":"Holly R W Pickett, Robert A Robinson, Robert L Nudds","doi":"10.1186/s40462-024-00497-3","DOIUrl":"10.1186/s40462-024-00497-3","url":null,"abstract":"<p><p>Migratory distances and stopover locations are changing for many passerines in response to climate change. Morphological changes have been linked to rising global temperatures in both migrants and residents, but the implications of these changes on fuel loads, and associated flight ranges are little studied. Wing length and body mass changes between 1964 and 2020 were calculated for 15 migrant and partially migrant passerines in Britain. Changes in fuel load and lean body mass were also estimated and used to predict flight ranges. Twelve of the species have undergone morphological changes and eight species, estimated fuel load changes. Nine species were estimated to have reduced flight ranges, indicating that the morphological changes have not compensated fully for the reduction in flight range experienced since 1964. Partial migrants showed greater decreases in flight ranges than did full migrants, which may indicate greater behavioural plasticity in the former. Those species which do not adapt morphologically or behaviourally may be unable to complete long migrations, resulting in restriction to sub-optimal breeding/wintering habitats, or a need for a sooner first stop and more stops en route. This highlights the importance of conserving migratory stopover sites, particularly in the Mediterranean and North Africa that immediately precede major geographical barriers, as-well-as breeding and wintering grounds.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"60"},"PeriodicalIF":3.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370066/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-09-02DOI: 10.1186/s40462-024-00499-1
Stefan Schoombie, Rory P Wilson, Yan Ropert-Coudert, Ben J Dilley, Peter G Ryan
{"title":"The efficiency of detecting seabird behaviour from movement patterns: the effect of sampling frequency on inferring movement metrics in Procellariiformes.","authors":"Stefan Schoombie, Rory P Wilson, Yan Ropert-Coudert, Ben J Dilley, Peter G Ryan","doi":"10.1186/s40462-024-00499-1","DOIUrl":"10.1186/s40462-024-00499-1","url":null,"abstract":"<p><strong>Background: </strong>Recent technological advances have resulted in low-cost GPS loggers that are small enough to be used on a range of seabirds, producing accurate location estimates (± 5 m) at sampling intervals as low as 1 s. However, tradeoffs between battery life and sampling frequency result in studies using GPS loggers on flying seabirds yielding locational data at a wide range of sampling intervals. Metrics derived from these data are known to be scale-sensitive, but quantification of these errors is rarely available. Very frequent sampling, coupled with limited movement, can result in measurement error, overestimating movement, but a much more pervasive problem results from sampling at long intervals, which grossly underestimates path lengths.</p><p><strong>Methods: </strong>We use fine-scale (1 Hz) GPS data from a range of albatrosses and petrels to study the effect of sampling interval on metrics derived from the data. The GPS paths were sub-sampled at increasing intervals to show the effect on path length (i.e. ground speed), turning angles, total distance travelled, as well as inferred behavioural states.</p><p><strong>Results: </strong>We show that distances (and per implication ground speeds) are overestimated (4% on average, but up to 20%) at the shortest sampling intervals (1-5 s) and underestimated at longer intervals. The latter bias is greater for more sinuous flights (underestimated by on average 40% when sampling > 1-min intervals) as opposed to straight flight (11%). Although sample sizes were modest, the effect of the bias seemingly varied with species, where species with more sinuous flight modes had larger bias. Sampling intervals also played a large role when inferring behavioural states from path length and turning angles.</p><p><strong>Conclusions: </strong>Location estimates from low-cost GPS loggers are appropriate to study the large-scale movements of seabirds when using coarse sampling intervals, but actual flight distances are underestimated. When inferring behavioural states from path lengths and turning angles, moderate sampling intervals (10-30 min) may provide more stable models, but the accuracy of the inferred behavioural states will depend on the time period associated with specific behaviours. Sampling rates have to be considered when comparing behaviours derived using varying sampling intervals and the use of bias-informed analyses are encouraged.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"59"},"PeriodicalIF":3.4,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370088/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-08-30DOI: 10.1186/s40462-024-00501-w
William F Fagan, Ananke Krishnan, Qianru Liao, Christen H Fleming, Daisy Liao, Clayton Lamb, Brent Patterson, Tyler Wheeldon, Ricardo Martinez-Garcia, Jorge F S Menezes, Michael J Noonan, Eliezer Gurarie, Justin M Calabrese
{"title":"Intraspecific encounters can lead to reduced range overlap.","authors":"William F Fagan, Ananke Krishnan, Qianru Liao, Christen H Fleming, Daisy Liao, Clayton Lamb, Brent Patterson, Tyler Wheeldon, Ricardo Martinez-Garcia, Jorge F S Menezes, Michael J Noonan, Eliezer Gurarie, Justin M Calabrese","doi":"10.1186/s40462-024-00501-w","DOIUrl":"https://doi.org/10.1186/s40462-024-00501-w","url":null,"abstract":"<p><p>Direct encounters, in which two or more individuals are physically close to one another, are a topic of increasing interest as more and better movement data become available. Recent progress, including the development of statistical tools for estimating robust measures of changes in animals' space use over time, facilitates opportunities to link direct encounters between individuals with the long-term consequences of those encounters. Working with movement data for coyotes (Canis latrans) and grizzly bears (Ursus arctos horribilis), we investigate whether close intraspecific encounters were associated with spatial shifts in the animals' range distributions, as might be expected if one or both of the individuals involved in an encounter were seeking to reduce or avoid conflict over space. We analyze the movement data of a pair of coyotes in detail, identifying how a change in home range overlap resulting from altered movement behavior was apparently a consequence of a close intraspecific encounter. With grizzly bear movement data, we approach the problem as population-level hypothesis tests of the spatial consequences of encounters. We find support for the hypotheses that (1) close intraspecific encounters between bears are, under certain circumstances, associated with subsequent changes in overlap between range distributions and (2) encounters defined at finer spatial scales are followed by greater changes in space use. Our results suggest that animals can undertake long-term, large-scale spatial changes in response to close intraspecific encounters that have the potential for conflict. Overall, we find that analyses of movement data in a pairwise context can (1) identify distances at which individuals' proximity to one another may alter behavior and (2) facilitate testing of population-level hypotheses concerning the potential for direct encounters to alter individuals' space use.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"58"},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11365178/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142114778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Movement EcologyPub Date : 2024-08-26DOI: 10.1186/s40462-024-00489-3
Hans Linssen, Henrik J de Knegt, Jasper A J Eikelboom
{"title":"Unveiling the roles of temporal periodicity, the spatial environment and behavioural modes in terrestrial animal movement.","authors":"Hans Linssen, Henrik J de Knegt, Jasper A J Eikelboom","doi":"10.1186/s40462-024-00489-3","DOIUrl":"10.1186/s40462-024-00489-3","url":null,"abstract":"<p><strong>Background: </strong>Animal movement arises from complex interactions between animals and their heterogeneous environment. To better understand the movement process, it can be divided into behavioural, temporal and spatial components. Although methods exist to address those various components, it remains challenging to integrate them in a single movement analysis.</p><p><strong>Methods: </strong>We present an analytic workflow that integrates the behavioural, temporal and spatial components of the movement process and their interactions, which also allows for the assessment of the relative importance of those components. We construct a daily cyclic covariate to represent temporally cyclic movement patterns, such as diel variation in activity, and combine the three components in a multi-modal Hidden Markov Model framework using existing methods and R functions. We compare the trends and statistical fits of models that include or exclude any of the behavioural, spatial and temporal components, and perform variance partitioning on the model predictions that included all components to assess their relative importance to the movement process, both in isolation and in interaction.</p><p><strong>Results: </strong>We apply our workflow to a case study on the movements of plains zebra, blue wildebeest and eland antelope in a South African reserve. Behavioural modes impacted movement the most, followed by diel rhythms and then the spatial environment (viz. tree cover and terrain slope). Interactions between the components often explained more of the movement variation than the marginal effect of the spatial environment did on its own. Omitting components from the analysis led either to the inability to detect relationships between input and response variables, resulting in overgeneralisations when drawing conclusions about the movement process, or to detections of questionable relationships that appeared to be spurious.</p><p><strong>Conclusions: </strong>Our analytic workflow can be used to integrate the behavioural, temporal and spatial components of the movement process and quantify their relative contributions, thereby preventing incomplete or overly generic ecological interpretations. We demonstrate that understanding the drivers of animal movement, and ultimately the ecological phenomena that emerge from it, critically depends on considering the various components of the movement process, and especially the interactions between them.</p>","PeriodicalId":54288,"journal":{"name":"Movement Ecology","volume":"12 1","pages":"57"},"PeriodicalIF":3.4,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11348775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142074461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}