Code and data supporting "Satellite telemetry reveals complex mixed movement strategies in ibis and spoonbills of Australia: implications for water and wetland management"" in Movement Ecology (2024) 12:74.

Full description

The data and files in these directories underpin analyses of telemetry data for Australia waterbird species. The goal is to understand the complex mixed 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.

In this analysis, we used a 7-year GPS satellite telemetry dataset of 122 individuals to investigate movement distances, residency periods and areas, and foraging‐site fidelity for straw-necked ibis (SNI), Australian white ibis (AWI), and royal spoonbill (RSB). Analyses include detailed summaries of the telemetry data and extensive home range analysis using auto-correlated kernel density estimation.

This research is led by CSIRO as part of the CEWH 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.
Lineage: Straw-necked ibis (‘SNI’) was chosen as the primary species for transmitter deployment because it is a focal species for Australian wetland and water managers that nests in large numbers in major inland wetlands managed with environmental water. Two other species that frequently nest and forage with SNI were also tracked, in smaller numbers, to explore potential differences among species: the royal spoonbill (‘RSB’) and the Australian white ibis (‘AWI’).

Transmitters were deployed at eight breeding sites within the Murray-Darling Basin in south-eastern Australia between 2016 and 2023. The Murray-Darling Basin is ≥ 106 km2 and is a primary focus for intensive water management and water policy reform in Australia. Many of the 16 internationally significant wet- lands in the Basin are located in these large floodplains and dependent on flooding including Ramsar-listed wetlands and some of the most important aggregate- nesting ibis and spoonbill breeding sites on the continent.

We captured birds either by hand, or with leg-nooses, or with a net launcher, depending on the site and environment. Birds were placed in large clean calico bags for weighing and other measurements. Juveniles were distinguished from adults by plumage, skin, leg, and size differences. Transmitters were attached as a ‘backpack’ using Teflon ribbon or Spectra ribbon (Bally Ribbon MillsTM) harnesses, fitted either as wing-loops with a join at the keel (SNI and AWI and some RSB), or as leg-loops (most RSB). Harness design was based on designs used in other species modified and improved over time, with different types of weak links used in different years. Transmitters weighed 12–40 g, ranging from <1% to 5% of bird bodyweight.

Solar-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 (Ornitela and 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.

Analyses were done in R version 4.3.1. Data for nesting adults, for adults and juveniles still within breeding sites post-capture but pre-dispersal, and for birds tracked for <30 days were removed. These removals were done to ensure results reflected longer-term movement statistics and patterns.