Colonial waterbird breeding at Narran Lakes: A history of breeding events and associated changes to hydrology
The Narran Lakes are a significant floodplain wetland complex within the Murray-Darling Basin. They are recognised as a wetland of national and international significance as a key site for colonial waterbird breeding. The most numerous breeding event for ibis (Straw-necked ibis, Threskiornis spinicollis) was recorded at Narran Lakes. Colonial waterbirds only breed when a threshold is reached coinciding with a major flood event. The wetland complex is currently experiencing the longest recorded period without a breeding event despite several medium to high flow events. Throughout the 1990s, there was considerable water resource development upstream of Narran Lakes affecting flooding and flows downstream. The draft water resource plan estimated that median flows to Narran Lakes would be reduced by 75%. In this paper, we examine the relationships between the breeding of colonial waterbirds and river flows in the Narran Lake system and possible effects of long term reductions in river flows.