Sentinel Birds of Coastal Risks
SENTI•RISK: Sentinel birds monitoring our changing coasts
The SENTI-RISK project (Sentinel Birds of Coastal Risks) is a research programme studying movement ecology to assess the vulnerability of the Bay of Biscay’s coastal interfaces in the face of global change. Whether pelagic and coastal seabirds (terns, gulls), wading birds exploiting coastal mudflats and saltmarshes (curlews, white storks), or species on migratory stopovers and wintering grounds, these sentinels navigate the land–sea continuum at key stages of their life cycle (breeding, dispersal, migration). Drawing on high-resolution GPS telemetry, the project aims to identify areas under anthropogenic pressure and analyse the behavioural plasticity of individuals in response to a changing environment.
Legend: Sentinel birds facing the gradient of coastal risks (Click to expand!)
Based on the representative example of the Pertuis Charentais, this diagram illustrates the connectivity between coastal ecosystems and the pressures studied by the project across the Bay of Biscay.
1 Offshore pressures and risks: This zone focuses on the intensification of offshore activities, notably the development of offshore wind farms and increased maritime traffic. Seabirds (terns, gulls) serve as indicators of the impacts of these new infrastructures.
2 Interface dynamics and global change: At the interface, this zone combines physical constraints associated with climate (temperatures, wind regimes) and coastal risks (tidal surges, mudflat erosion). The sentinels of this zone (gulls, curlews, brent geese) reveal the adjustment capacity of populations in response to modifications in their feeding grounds.
3 Terrestrial and inland anthropogenic pressures: Corresponding to the catchment area, this zone is directly affected by the impacts of urbanisation, intensive agriculture, and industrial sites. Species nesting or foraging inland (gulls, white storks) enable the quantification of pressure displacement from the coast towards the mainland.
The role of sentinel species: At the top of the diagram, the GPS-tracked species act as indicators reflecting the magnitude of these three major land–sea pressure classes.
The coastline: an interface under cumulative pressures
Coastal areas, acting as genuine interfaces between marine and terrestrial ecosystems, are among the most vulnerable environments today. These environments bear the full brunt of cumulative impacts linked to a dual threat (e.g. He & Silliman, 2019):
- Global upheaval: Climate breakdown imposes widespread stress, characterised by sea warming, sea-level rise, ocean acidification, and deoxygenation.
- Intensification of local pressures: Direct anthropogenic disturbances compound this global baseline. At sea, habitats are affected by the expansion of offshore wind developments, increased shipping lanes, and interactions with commercial fisheries. On land, encroaching urbanisation and infrastructure disrupt natural connectivity with the ocean, whilst intensive agriculture causes excessive nutrient run-off leading to coastal eutrophication and contaminant dispersal.
The SENTI•RISK objective: In response to the escalation of these combined threats, the project tracks top predators as ecological sentinels. By modelling their interactions with these diverse pressures, we aim to map conflict hotspots and key ecological corridors, delivering practical decision-support tools for coastal resilience and sustainable management.
Our scientific approach
Legend: High-resolution GPS-GSM telemetry tracking
This diagram outlines our data acquisition methodology across the habitat gradient. Birds are fitted with miniaturised tags that continuously record their spatial coordinates and behaviours. These tags utilise the GSM (Global System for Mobile Communications) network to relay gathered data via terrestrial mobile networks, allowing near real-time data transmission whenever birds approach coastal or mainland relay masts.
1. Habitat selection modelling (Step Selection Functions)
We monitor a complementary suite of species whose movements span the entire gradient, from the open sea to inland marshes. From GPS tracking datasets, we apply trajectory analysis models termed ‘Step Selection Functions’ (SSF). This statistical framework contrasts observed animal movements against simulated random steps to deduce habitat preferences mathematically. When scaled across multiple species, this method quantifies attraction or avoidance behaviours in the face of cumulative pressures and pinpoints vital ecological corridors at a landscape scale.
Particular emphasis is placed on early life-history stages (juveniles). Lacking experience, naive individuals explore their environment differently and are frequently more vulnerable to anthropogenic and environmental stressors. By integrating developmental stages into our analytical models, these young birds act as early indicators of emerging ecosystem dysfunction. We hypothesise that investigating their behavioural plasticity under multiple risks is essential to predicting the adaptive potential and long-term viability of populations facing global change.
Legend: Analytical modelling via Step Selection Functions
This figure outlines the analytical workflow used to quantify the response of sentinel birds to anthropogenic and environmental pressures.
A. Step selection framework: Observed trajectories (blue points) are compared against ‘random’ alternative locations (red points) drawn from empirical step-length and turning-angle distributions.
B. Multi-layer integration: Movement trajectories are intersected with coastal risk layers and environmental covariates.
C. Modelling in R: Statistical analyses estimate the probability of habitat selection or avoidance under cumulative environmental pressures.
Institutional and collaborative framework
Hosting institution & synergies: The project is hosted at the Centre d’Études Biologiques de Chizé (CEBC – UMR 7372 CNRS / La Rochelle University). It forms an integral part of La Rochelle University’s interdisciplinary ecosystem, sitting at the crossroads of movement ecology, data science, and coastal research.
Partnerships: The project relies on a multidisciplinary consortium bringing together state agencies, public research institutes, recognised charities, and accredited conservation bodies. Collaborations encompass telemetry data sharing, technical support for device deployment, and schools-based scientific engagement initiatives.
Team & Students: A three-year doctoral project (2025–2028) is currently underway and a six-month Master’s dissertation (2026) has concluded. A forthcoming Master’s placement will be advertised shortly.
Science & Society: Public outreach and school educational programmes are co-ordinated alongside the University’s Science and Society team.
This work benefits from French State funding managed by the French National Research Agency under the France 2030 investment plan (reference ANR-21-EXES-0010).
