School of Biological and Chemical Sciences

Liam Dickson


PhD student



Project title: Managing mobile species from individuals to populations: Elucidating environmental factors driving species aggregations

Summary: Animal aggregation is a global phenomenon in both terrestrial and aquatic ecosystems, as a response to social and/or environmental cues. Yet, the factors that influence spatial and temporal dynamics of aggregations remain mostly elusive. In the marine environment, specific challenges exist to locate and monitor animals that spend much of their lives below the sea surface. Technological advances in remote tracking allow researchers to collect large quantities of spatial data on individuals in pelagic and coastal areas; however, this equipment remains costly and, as such, research determining movement and distribution at the population level in the marine environment is limited.

To fill this remaining major knowledge gap, this study will use emerging Unmanned Aerial Vehicle (UAV) technology to determine the factors that drive the formation and structure of sea turtle aggregations in the coastal waters off western Greece. Because this location supports ~60% of the Mediterranean’s sea turtle stock, it is of both local and global concern. Specifically, I will use UAV surveys to investigate what environmental factors drive variation in (1) timing (phenology) of breeding at the population level across years at multiple sites, and (2) the geographic distribution of breeding aggregations, including seasonal and annual variation in the spacing and orientation of individuals within aggregations. For a global perspective, I will use these results to predict how turtles aggregate at other sites globally based on available environmental, nesting and tracking data to inform conservation efforts at key protection sites. In particular, I will quantify the value of population-scale data derived from UAV surveys against high-resolution tracking data of individual animals, to provide practical suggestions for conservation management. Through using UAVs, I will gain much needed population-level information on the cues and structure of sea turtle aggregations to provide new insights into the ecological processes driving this phenomenon globally. Ultimately, this work will provide recommendations for the management and conservation of aggregating marine species.