Near-exclusive use of non-native grasses by the Variegated Fairy-wren (Malurus lamberti) in a heavily modified habitat

Paulo Ditzel, Elisa Resendez, James Kennerley, Paul Kessler, Emma Buckley, Claire Huff, Colleen Poje, Jonathan Coleman, Michael Webster, Jordan Boersma, William Edgar Feeney

Successful breeding is a critical component of a bird’s life-history, but preferred nesting habitats remain little studied in many Australian species. In southeastern Queensland, a revegetated site shows high bird biodiversity and density, despite being dominated by invasive understory plants. Here, we describe the relative cover of grass species present (Poaceae) at our study site and determine how often Variegated Fairy-wren (Malurus lamberti) nests were built in each species during the 2023 breeding season. We found that the majority of grass cover involved invasive species. Birds used invasive grass species almost exclusively as construction substrate, and as material to build their nests. Our results suggest that invasive grass species may not have had a negative impact on the breeding habits of fairy-wrens.