Citizen science backs bird conservation

27 Jul 2023

This year marks the 20th year of a strong and enduring partnership between Sydney Olympic Park Authority and Cumberland Bird Observers’ Club (CBOC). Since 2004, over 50 CBOC members have volunteered their time and energy to several long-term bird survey programs every year, helping to build a picture of bird numbers and diversity on a scale impossible to achieve for any individual researcher or the Authority alone.

CBOC has been a birdwatching club since 1979, and its members are highly valued for their field experience and scientific knowledge.  At Sydney Olympic Park, they survey in all habitat types –from endangered Sydney Turpentine Ironbark Forest remnant, restored woodlands, freshwater wetlands to estuarine wetland with mangroves and coastal saltmarsh. 

Three volunteers with survey equipment amongst woodland vegetation.

Bird survey in Sydney Turpentine Ironbark Forest

Citizen scientists in action

Bird surveys conducted by CBOC volunteers include:

  • Spring Bird Census – weekly surveys of 44 quadrats over 8 weeks in spring
  • Evening waterbird survey – 4 surveys of migratory shorebirds in spring and summer
  • Latham’s Snipe survey – 3 surveys of the migratory Latham’s Snipe in spring and summer

Over 200 native bird species have been recorded in the Park. These surveys provide data fundamental to understanding the bird populations at the Park, and answer important questions such as:

  • General population trends - how does species richness and abundance change over time?
  • Is the population of aggressive species such as Noisy Miners increasing with time? Is the population of declining small woodland birds improving over time?
  • Has the Authority’s management actions (e.g. habitat creation and restoration) improved the outlook for birds?
Group photo of the 2022 Spring Bird Census volunteers in the Park.

Female Musk Duck foraging for food at Narawang Wetland.

What have CBOC volunteers found?

Survey highlights include: 

  • Observing about 2,000 individual birds per week during the Spring Bird Census, and recording a long-term average of 116 native bird species per year for the Park.
  • Recording 12 species of migratory shorebirds since 2004, including two endangered Eastern Curlews in 2021, last seen in the Park 11 years prior; these sightings help conserve the habitat of these species, some of which have declined in population by 80% or more.
  • Observing more than 18 Latham’s Snipe (18 being the commonwealth threshold for ‘’Nationally Important Sites’’) in Narawang Wetland, making the wetland a ‘’Nationally Important Site’’ since 2018-19
  • Observing breeding activity in 41 species across the Park in 2022, including many valuable sightings of juveniles; this is comparable to previous years. 
  • understanding bird movements, such as the increase in waterbirds in Park wetlands during droughts, and near total disappearance of some waterbirds to inland wetlands created by rain and floods.
Three volunteers with survey equipment amongst wetland vegetation.

Volunteers get the best views

These surveys also ring alarm bells for some species and drive increased monitoring activity or adaptive conservation actions to arrest their decline. For example, a decline in Red-rumped Parrots was picked up by regular surveys, and nest boxes were installed to mitigate the lack of tree hollows they need for breeding. Since then, population has increased three-fold with successful breeding at nest boxes observed every year since 2012. 

The latest surveys show the Noisy Miner remain the most abundant species in the Park, and breed in more precincts than all other species. This is highly concerning as the Noisy Miner is an aggressive species that actively exclude other birds from their territory. The Authority has been increasing shrub cover to shift the balance in favour of small woodland birds that need shelter and protection from Noisy Miners. Surveys suggest Noisy Miner numbers have decreased compared to a height in 2018, and small woodland birds are able to persist in some areas with a dense, shrubby understorey. 

Birds at the Park are subject to a litany of threats including predation by feral animals, light, noise and water pollution, collision with windows or cars, secondary poisoning and more. Continued ecological monitoring is an integral part of identifying and responding to known threats and new issues. The Authority would like to take this opportunity to thank CBOC and its volunteers for their long-running contribution to understanding and protecting birds.