Applications of digital imaging and analysis in seabird monitoring and research

Rapid advances in digital imaging technology offer efficient and cost-effective methods for measuring seabird abundance, breeding success, phenology, survival and diet. These methods can facilitate understanding of long-term population trends, and the design and implementation of successful conservation strategies. This paper reviews the suitability of satellites, manned aircraft, unmanned aerial vehicles (UAVs), and fixed-position, handheld and animal-borne cameras for recording digital photographs and videos used to measure seabird demographic and behavioural parameters. It considers the disturbance impacts, accuracy of results obtained, cost-effectiveness and scale of monitoring possible compared with 'traditional' fieldworker methods. Given the ease of collecting large amounts of imagery, image processing is an important step in realizing the potential of this technology. The effectiveness of manual, semi-automated and automated image processing is also reviewed. Satellites, manned aircraft and UAVs have most commonly been used for population counts. Spatial resolution is lowest in satellites, limiting monitoring to large species and those with obvious signs of presence, such as penguins. Conversely, UAVs have the highest spatial resolution, which has allowed fine-scale measurements of foraging behaviour. Time-lapse cameras are more cost-effective for collecting time-series data such as breeding success and phenology, as human visits are only required infrequently for maintenance. However, the colony of interest must be observable from a single vantage point. Handheld, animal-borne and motion-triggered cameras have fewer cost-effective uses but have provided information on seabird diet, foraging behaviour and nest predation. The last of these has been important for understanding the impact of invasive mammals on seabird breeding success. Advances in automated image analysis are increasing the suitability of digital photography and videography to facilitate and/or replace traditional seabird monitoring methods. Machine-learning algorithms, such asPengbot, have allowed rapid identification of birds, although training requires thousands of pre-annotated photographs. Digital imaging has considerable potential in seabird monitoring, provided that appropriate choices are available for both image capture technology and image processing. These technologies offer opportunities to collect data in remote locations and increase the number of sites monitored. The potential to include such solutions in seabird monitoring and research will develop as the technology evolves, which will be of benefit given funding challenges in monitoring and conservation.

Automated summary

Rapid advances in digital imaging technology provide efficient and cost-effective methods for monitoring seabirds, aiding in understanding long-term population trends and designing successful conservation strategies. Satellites, manned aircraft, and UAVs are commonly used for population counts, while time-lapse cameras are more suitable for collecting data on breeding success and phenology.