Habitat heterogeneity is considered a primary causal driver underpinning patterns of diversity, yet the universal role of heterogeneity in structuring biodiversity is unclear due to a lack of coordinated experiments testing its effects across geographic scales and habitat types. Furthermore, key species interactions that can enhance heterogeneity, such as facilitation cascades of foundation species, have been largely overlooked in general biodiversity models. Here, we performed 22 geographically distributed experiments in different ecosystems and biogeographical regions to assess the extent to which variation in biodiversity is explained by three axes of habitat heterogeneity: the amount of habitat, its morphological complexity, and capacity to provide ecological resources (e.g. food) within and between co-occurring foundation species. We show that positive and additive effects across the three axes of heterogeneity are common, providing a compelling mechanistic insight into the universal importance of habitat heterogeneity in promoting biodiversity via cascades of facilitative interactions. Because many aspects of habitat heterogeneity can be controlled through restoration and management interventions, our findings are directly relevant to biodiversity conservation.

Coastal ecosystems are under threat from a range of anthropogenic impacts that disrupt habitat connectivity and the ability for animals to move within them. Understanding fine-scale animal movement provides insight into how animals are responding to these pressures, and underpins effective ecological management and conservation strategies. This study used drones to investigate the drivers of the fine-scale movement of rays in coastal estuaries using the short-tail stingray (Bathytoshia brevicaudata) as a model species. Smaller rays swam with more regular bursts of speed and greater sinuosity than larger individuals, indicating that rays of different sizes alter their fine-scale movement behavior to maintain energetic efficiency. Rays were less likely to spend time resting and swam faster on the high tide compared to the outgoing tide. They were also more likely to exhibit bursts of speed at noon (11 am to 1 pm) than at other times of day. Body size, tide and time of day all influenced ray movement. Understanding the ecological variables that influence the fine-scale movement of rays and the potential for human activities to alter natural behaviors is integral to the implementation of effective management strategies for this group of animals and their ecosystems.

The way an animal behaves in its habitat provides insight into its ecological role. As such, collecting robust, accurate datasets in a time-efficient manner is an ever-present pressure for the field of behavioural ecology. Faced with the shortcomings and physical limitations of traditional ground-based data collection techniques, particularly in marine studies, drones offer a low-cost and efficient approach for collecting data in a range of coastal environments. Despite drones being widely used to monitor a range of marine animals, they currently remain underutilised in ray research. The innovative application of drones in environmental and ecological studies has presented novel opportunities in animal observation and habitat assessment, although this emerging field faces substantial challenges. As we consider the possibility to monitor rays using drones, we face challenges related to local aviation regulations, the weather and environment, as well as sensor and platform limitations. Promising solutions continue to be developed, however, growing the potential for drone-based monitoring of behaviour and habitat use of rays. While the barriers to enter this field may appear daunting for researchers with little experience with drones, the technology is becoming increasingly accessible, helping ray researchers obtain a wide range of highly useful data.

The original version of this Article contained an error in Fig. 1, in which the illustration depicting a Diopatra tube mimic was missing. This has been corrected in both the PDF and HTML versions of the Article.