Upper Merrimajeel Straw-necked Ibis Colony

4-5/10/2016: Corey Callaghan, Diane Harshbarger, and John Porter

Obvious detrimental effects have been documented as a result of recent heavy rains and flooding throughout NSW, but it has been quite favourable for the waterbirds. A recent ground survey from the Lachlan Valley SCA in Booligal indicates a successful nesting colony of Straw-necked Ibis. In previous years the number of Straw-necked ibis reached over 60,000; currently there are estimated to be 30,000 birds with 15,000 nests. Small numbers of White Ibis and Royal Spoonbill were recorded to be nesting in the region also. 

In addition to documenting establishment and growth of the colony, our goal is to determine the nest success and mortality rates. We do this by tagging clumps of nest and counting eggs, chicks, squirters, and runners throughout the nesting season. 

Corey Callaghan and John Porter counting eggs and chicks

Left: clump of nests; right: 2 chicks and a hatching egg

The colony is located within the Lachlan River floodplain and, as such, birds can be found building nests in elevated areas or on the edges of deeper ravines, as long as lignum is present for their nests. Due to high water levels, many of the nest clumps were only accessible via canoe. As we move through the colony large flocks of birds fly in all directions, but they return to their young much more quickly than you would expect.

Traversing the Upper Merrimajeel Colony


Colonial Waterbirds
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