Modelling the niche for a marine vertebrate: a case study incorporating behavioural plasticity, proximate threats and climate change

Pikesley, Stephen K.; Broderick, Annette C.; Cejudo, Daniel; Coyne, Michael S.; Godfrey, Matthew H.; Godley, Brendan J.; López, Pedro Antonio; López-Jurado, Luis Felipe; Merino, Sonia Elsy; Varo-Cruz, Nuria; Witt, Matthew J.; Hawkes, Lucy A.

doi:10.1111/ecog.01245

Cited by 44 publications

(34 citation statements)

References 58 publications

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“…McClellan & Read 2007;Arendt et al 2012a;Varo Cruz et al 2016). Adults, too, have been sometimes observed foraging in oceanic zones while displaying wandering movements, either when tracked soon after migrating away from breeding/nesting areas (Hatase et al 2002;Hawkes et al 2006;Schofield et al 2010;Pikesley et al 2015;Mingozzi et al 2016) or in periods outside the breeding season (Bentivegna 2002;Kobayashi et al 2011;Casale et al 2013;Luschi et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Large-scale movements in the oceanic environment identify important foraging areas for loggerheads in central Mediterranean Sea

et al. 2017

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Loggerhead sea turtles (Caretta caretta) are known to display a wide range of movement patterns during the different stages of their life cycle, but empirical information to document this extensive behavioural plasticity is still limited. This is especially true for large, adultsized individuals, that are thought to mainly forage in neritic areas. In the present paper, eight adult-sized loggerhead turtles were tracked using satellite telemetry to identify the location of their foraging grounds in the seas along the western coast of the Italian peninsula. Tracked turtles mostly stayed in the region between the Italian peninsula and the islands of Sicily and Sardinia, that was reached following quick, directed movements by the turtles from a release site to the north. In this area, two turtles took up residence in spatially-limited neritic sites along the coast, while the remaining six alternated circumscribed coastal stays with long-distance, circuitous movements in the oceanic environment. An utilization distribution analysis clearly identified an area, mostly comprising oceanic waters, that was continuously used by turtles in different seasons and years. The present results contribute to the still-limited knowledge of the spatial ecology of loggerheads frequenting the Western Mediterranean Sea and highlight the presence of a potentially important oceanic region in the Southern Tyrrhenian Sea where adult-sized turtles forage for extended periods. These findings increase our knowledge of complex life history traits of loggerhead turtles and provide important information to be considered for evidence-based conservation measures.

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Section: Introductionmentioning

confidence: 99%

Large-scale movements in the oceanic environment identify important foraging areas for loggerheads in central Mediterranean Sea

et al. 2017

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“…sea surface temperature, SST) environmental variables are widely used in model construction (Michael et al ). Remotely‐sensed data fields are most often used as dynamic variables (Block et al , Nur et al , Becker et al , Pikesley et al ), although oceanographic models (e.g. Regional Ocean Model System, ROMS) are becoming more widely used for this purpose because outputs provide valuable sub‐surface information and are not cloud‐affected (Becker et al ).…”

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confidence: 99%

Scale of inference: on the sensitivity of habitat models for wide‐ranging marine predators to the resolution of environmental data

et al. 2016

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Understanding and predicting the responses of wide‐ranging marine predators such as cetaceans, seabirds, sharks, turtles, pinnipeds and large migratory fish to dynamic oceanographic conditions requires habitat‐based models that can sufficiently capture their environmental preferences. Marine ecosystems are inherently dynamic, and animal–environment interactions are known to occur over multiple, nested spatial and temporal scales. The spatial resolution and temporal averaging of environmental data layers are therefore key considerations in modelling the environmental determinants of habitat selection. The utility of environmental data contemporaneous to animal presence or movement (e.g. daily, weekly), versus synoptic products (monthly, seasonal, climatological) is currently debated, as are the trade‐offs between near real‐time, high resolution and composite (i.e. synoptic, cloud‐free) data fields. Using movement simulations with built‐in environmental preferences in combination with both modelled and remotely‐sensed (ROMS, MODIS‐Aqua) sea surface temperature (SST) fields, we explore the effects of spatial and temporal resolution (3–111 km, daily–climatological) in predictive habitat models. Results indicate that models fitted using seasonal or climatological data fields can introduce bias in presence‐availability designs based upon animal movement datasets, particularly in highly dynamic oceanographic domains. These effects were pronounced where models were constructed using seasonal or climatological fields of coarse (> 0.25 degree) spatial resolution. However, cloud obstruction can lead to significant information loss in remotely‐sensed data fields. We found that model accuracy decreased substantially above 70% data loss. In cloudy regions, weekly or monthly environmental data fields may therefore be preferable. These findings have important implications for marine resource management, particularly in identifying key habitats for populations of conservation concern, and in forecasting climate‐mediated ecosystem changes.

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“…, Pikesley et al. ), as well as an increasing availability of long‐term and high‐resolution animal movement data sets. The fusion of both provides a promising approach to extract an environmentally informed behavioral signature from the trajectories of single individuals as well as groups of animals.…”

Section: Discussionmentioning

confidence: 99%

Temporal segmentation of animal trajectories informed by habitat use

Toor

Newman²,

Takekawa

et al. 2016

Ecosphere

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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.

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Modelling the niche for a marine vertebrate: a case study incorporating behavioural plasticity, proximate threats and climate change

Cited by 44 publications

References 58 publications

Large-scale movements in the oceanic environment identify important foraging areas for loggerheads in central Mediterranean Sea

Large-scale movements in the oceanic environment identify important foraging areas for loggerheads in central Mediterranean Sea

Scale of inference: on the sensitivity of habitat models for wide‐ranging marine predators to the resolution of environmental data

Temporal segmentation of animal trajectories informed by habitat use

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