Data supporting "Satellite-tracked movements of juvenile Great Egrets (Ardea alba) and Plumed Egrets (Ardea plumifera) from the Macquarie Marshes, Murray-Darling Basin, Australia" in Pacific Conservation Biology (2025)

The data and files in these directories underpin analyses of telemetry data for two Australian waterbird species. The goal is to understand the movement strategies of these species across their life cycles in order to assist effective management. Many waterbirds are highly mobile at a range of spatial and temporal scales, which makes monitoring challenging when using traditional methods such as on-ground surveys or leg-banding.\n\nIn this analysis, we used a GPS satellite telemetry dataset of 18 juveniles to investigate the movement patterns of Great and Plumed Egrets captured at the Macquarie Marshes (NSW). The study analysed dispersal movements, including timing, directions, distances, and stopover sites, as well as post-dispersal daily movement timing and distances travelled between roosts and foraging sites.\n\nThis research is led by CSIRO as part of the Commonwealth Environmental Water Holder's Monitoring, Evaluation and Research Program (Flow-MER). It builds on and incorporates satellite tracking of straw-necked ibis, Australian white ibis and royal spoonbills conducted by CSIRO between 2016–19 as part of the Environmental Water Knowledge and Research (EWKR) Waterbird Theme. The EWKR research identified a need for additional satellite tracking of species dependent on water to feed (such as spoonbills and egrets), not just to breed (such as ibis), and for tracking of the movements of birds from additional important sites across the Basin. \n\nThe dataset in this collection consists of supporting code and files for manuscript "Satellite-tracked movements of juvenile Great Egrets (Ardea alba) and Plumed Egrets (Ardea plumifera) from the Macquarie Marshes, Murray-Darling Basin, Australia" published in Pacific Conservation Biology (2025). The dataset contains mp4 video files of animations of the movement paths of three tracked egrets, and code and associated figures that show the post-dispersal movement and resting behaviour of tracked egrets. Refer to the readme file for further information about the files.\nLineage: Great and Plumed Egrets were chosen for transmitter deployment because they are focal species for Australian wetland and water managers that nest in large numbers in major inland wetlands managed with environmental water. \n\nTransmitters were deployed at the Macquarie Marshes (NSW) in the Murray-Darling Basin in south-eastern Australia in 2023. The Murray-Darling Basin is Australia's largest river system and a primary focus for intensive water management and water policy reform in Australia. The Macquarie Marshes is one of the most important aggregate- nesting waterbird breeding sites on the continent.\n\nBirds were captured by hand and placed in large clean calico bags for weighing and other measurements. Transmitters were attached as a ‘backpack’ using Teflon ribbon harnesses fitted as leg-loops. Harness design was based on designs used in other species modified and improved over time. Transmitters weighed 12 g and were 1.35% ± 0.06% (mean ± SE) and 2.69% ± 0.09% of the bird’s body weight for Great and Plumed Egrets, respectively.\n\nSolar-powered GPS transmitters with a fix accuracy of 15–26 m were used, with data sent through either the Argos satellite network (Geotrak units) or the 3G network (Druid units). The frequency of fixes ranged from every min to every 6 hours, depending on the transmitter type and programmed schedule. This was handled in analyses, with interpolation or down-scaling applied when appropriate.