Aerial surveys of waterbirds in Australia

Eastern Australian Waterbird Survey

This is one of the largest wildlife surveys in Australia and the world, surveying major wetland sites across eastern Australia, providing invaluable information on the ecosystem health of wetlands and rivers. These surveys are run annually. They provide long-term data as essential baseline information for assessing changes, including direct and indirect anthropogenic impacts on freshwater ecosystems. They also provide long-term objective data on waterbird populations for eastern Australia.

In October of each year, waterbirds across eastern Australia are counted on up to 2000 wetlands (100 hours flying). Abundance indices for all waterbird species are collected on every wetland surveyed. An area of 2,697,000 km2 is systematically sampled within ten survey bands 30 km in width, spaced every 2° of latitude from 38°30’S to 20°30’S (Kingsford et al. 2020; Fig.1).

The Eastern Australian Waterbird Survey began in 1983, when eastern states governments (Queensland, New South Wales, Victoria and South Australia), the Commonwealth Government and the CSIRO began an ambitious program to monitor waterbirds across one third of the continent, from the east coast to the Northern Territory border and from Prosperpine in northeastern Queensland to south of Melbourne. From 1987 to 2004, the survey project was run by the New South Wales Government Environment Agency. Since 2005, the project has been run by the Centre for Ecosystem Science, UNSW Sydney, in collaboration with the eastern State Governments and the Australian Government. 

Figure 1. Ten aerial survey bands (each 30 km in width), every two degrees of latitude, crossing eastern Australia to monitor up to 2000 wetlands and provide estimates for up to 50 species of waterbirds in October each year (1983-2024).

Surveying Lake Alexandrina, 2025

Methods for aerial surveys of waterbirds

The aerial survey program employs a rigorous and repeatable methodology to aerial surveys. The same methods and time of year are used for aerial surveys to ensure long-term comparability of survey data and minimise bias. Waterbird surveys use a high-winged aircraft (Cessna), with a pilot and two observers: a front-right observer (beside the pilot), the navigator, and a back-left observer (behind the pilot). The aircraft is flown at a height of 30-46m and a speed of 167-204km hr^-1, within 150m of the shoreline, where waterbirds usually congregate. Each wetland surveyed has a unique code, allowing survey records to be matched between the two observers. Synchronised clocks and a recorded GPS track ensure that data are temporally and spatially explicit.

The two observers, one each side of the plane, identify and estimate numbers of more than 50 species of waterbirds on each wetland, including nests and broods, onto digital recorders. Most waterbirds are identified to species, apart from four groups which cannot be reliably separated from the air: small egrets (3 species), small grebes (2 species), small (>20 species) and large (>5 species) migratory waders. In addition, the percentage fullness of the freshwater ecosystem (relative to its flooding boundary) is estimated. Either an entire wetland is circumnavigated, or a proportion of the wetland (> 50 %).

Counts for each species are totalled for each observer and extrapolated to provide a total count, if only a proportion is counted. Each wetland has an estimated total count of waterbirds. The team also implements rigorous collection and storage of data. Timeliness is critical because state governments rely on the data for management of duck hunting open seasons by the end of each year. The Team has developed a dedicated database with internal quality assurance data checking and linking of data through unique identifiers for each wetland. Data are entered using a developed application, allowing error checking of wetland locations, names, waterbird species’ names and dates. During data entry, a time-stamped GPS track of the survey path is used to ensure that any navigational issues, such as erroneous georeferencing, are corrected using the GPS time recorded during the surveys. All data are incorporated into a MySQL database, allowing subsequent error checking, identification and correction. The database uses structured query language (SQL) to link with GIS software and deliver the database online via a server, allowing temporal, spatial and taxonomic retrieval of data by the public. Waterbird and wetland data are entered and stored in a relational SQL database, Australian Waterbird Surveys. 

Communication

We developed a blog to provide real-time information, including photographs and video footage each day of surveys to the public. Long-term data are also reported to governments each year, in an annual summary. In addition, there is a strong focus on analyses in real time and historical data to inform environmental water management. During surveys, this includes identification of the extent of flooding, and rookery sites for waterbird breeding to inform environmental water managers on protecting and managing these key waterbird breeding sites each year, even in difficult to access areas. There is also a strong commitment to communicating more broadly to the public through radio, print, social media, online and television. There is now considerable understanding about the importance of these data for tracking changes in the environment and informing governments and communities.

To view highlights and gain an insight to the condition of wetlands in eastern Australia over October and November 2025, select a day of the blog by using our interactive flight sections on the map below.