Waterbird and shorebird surveys of the Bowling Green Bay Ramsar site

2012
Driscoll P., Milton D. and Harding S.

A report to the Department of Sustainability, Environment, Water, Population and Communities

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About the document

This research project was funded by the Australian Government Department of Sustainability, Environment, Water, Population and Communities, as part of the Queensland Wetlands Program.

Executive Summary of Report

Bowling Green Bay was declared a Ramsar site in 1996 as it met several of the criteria for a wetland of international importance. Two of the criteria that it met were:

  1. the provision of habitat to support over 20,000 waterbirds, including large populations of Magpie Geese and Brolga; and
  2. supported 1% of the East Asian -Australasian Flyway population of one species of shorebird: Black-tailed Godwit.

The Australian Government has commissioned the development of ecological character descriptions (ECDs) for Australian Ramsar sites, to establish the critical components, processes and services that underpin the Ramsar criteria and to assist with establishing limits of acceptable change (LAC) for the sites.

During the preparation of the draft ECD for the Bowling Green Bay Ramsar site (BGBRS) a lack of sufficient data meant that it was not possible to demonstrate that the BGBRs supported Ramsar criterion (5). Furthermore, the available data on shorebird numbers were considered inadequate for setting a LAC for their populations.

The lack of sufficient data relating to the two Ramsar criteria relevant to the BGBRS resulted in a year-long study of the numbers of shorebirds and waterbirds at the site. The study began in May 2011 with funding provided by the Australian Government Department of Sustainability, Environment, Water, Population and Communities. The study comprised four surveys of the coastal high tide roosts in the BGBRS for shorebirds and additional aerial and ground surveys of nearby wetlands (north of Ayr). The aim of the study was to provide a detailed assessment of the distribution and abundance of shorebirds and waterbirds in the BGBRS. It was anticipated that these data would provide sufficient information to develop LACs for shorebirds and waterbirds.

Key findings of the study include:

  • Confirmation of the regional importance of the BGBRS for migratory shorebirds and resident and transient waterbirds.
  • The Black-tailed Godwit does not appear to regularly occur at the Ramsar site in internationally significant numbers. However, there is evidence that the Great Knot more regularly occurs in internationally significant numbers.
  • The most abundant waterbird species in the survey area were the Magpie Geese and the Pacific Black Duck.
  • Over the course of the study, the majority of the waterbirds occurred outside, but adjacent to, the Ramsar site, where the numbers of four species were in internationally significant numbers. This demonstrated the importance of neighbouring wetland habitat, particularly at locations south and south-west of the site, which are extensively used by waterbirds.
  • While parts of the BGBRS have been extensively surveyed since the mid-1990s, a systematic and coordinated program of surveys has been lacking. This has made it difficult to identify trends in shorebird populations and then provide quantitative LACs.
  • It will be difficult to identify LACs for shorebirds and waterbirds at the site, given the mobility of the bird species, their use of habitats outside the Ramsar site and the difficulty in quantifying change in population numbers. Suggestions are made as to potential monitoring approaches.

See also