Fine-scale habitat partitioning of sympatric stingrays revealed by drone-based remote sensing and deep learning

Habitat partitioning supports the coexistence of sympatric species and shapes their ecological roles across coastal seascapes. Understanding how sympatric species move through and use coastal habitats therefore provides fundamental ecological insight. Aerial drones provide new opportunities to monitor fine-scale movement and habitat utilisation of elasmobranchs in shallow waters. Here, we use drones to investigate fine-scale habitat partitioning and foraging behaviour among stingrays in a coastal lagoon in the central Red Sea. We conducted 30 aerial transect surveys (~17 ha each) and tracked 40 rays and 1 shark (total tracking time > 23 h). Using a double-observer protocol (manual + AI-assisted), 1,468 rays (6 species) and 4 sharks (2 species) were recorded from the transect surveys. Transect detections were dominated by bluespotted ribbontail rays (Taeniura lymma; n = 1,221) and larger-bodied whiprays (predominantly Himantura uarnak; n = 187). AI-assisted image analysis outperformed human analysts detecting 97% of these observations, compared to 76% for human analysts. We found pronounced habitat partitioning at sub-kilometre scales: bluespotted rays occupied the shallowest (< 0.4 m deep) lagoonal areas, away from open water, with foraging-related digging concentrated along the mangrove edge, identifying this zone as a key feeding ground and bioturbation hotspot. Whiprays predominated on macroalgal reef flat habitats and appeared to forage non-disruptively on epifaunal prey. Both taxa aggregated with conspecifics. Together, our results demonstrate that contrasting micro-habitat preferences and foraging strategies structure the spatial ecology of sympatric stingrays and highlight how drone-based monitoring coupled with AI can scale ecological inference in nearshore ecosystems. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=108 SRC="FIGDIR/small/710512v1_ufig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@1cefdd9org.highwire.dtl.DTLVardef@7bc807org.highwire.dtl.DTLVardef@895540org.highwire.dtl.DTLVardef@3c146b_HPS_FORMAT_FIGEXP M_FIG C_FIG