Different Down-Under: How Australian avian breeding phenology differs relative to the Northern Hemisphere
Daisy Englert Duursma (1), Rachael Gallagher (2), Simon Griffith (3)
1 Macquarie University, Department of Biological Sciences, North Ryde, NSW 2109, daisy.duursma@mq.edu.au
2 Macquarie University, Department of Biological Sciences, North Ryde, NSW 2109, rachael.gallagher@mq.edu.au
3 Macquarie University, Department of Biological Sciences, North Ryde, NSW 2109, simon.griffith@mq.edu.au
Bird breeding phenology is responding to rapidly changing climate conditions. Knowledge of current phenological patterns and their rates of change are important for understanding life-‐history, behaviour and ecology of birds and should be incorporated into conservation assessments. Documented shifts in avian phenology are particularly pronounced in the Northern Hemisphere. Recent reviews of changes in annual cycles of birds are dominated by examples from Northern Hemisphere temperate regions. We collated and analysed 245 years of breeding bird observations on the Australian continent and assessed the start, conclusion, length, and seasonal density of breeding observations for 339 Australian birds at the continental scale and across five biomes. We show that Australian birds have significantly longer peak breeding periods than birds in the Northern Hemisphere and that peak breeding period timing and length varies by biome. Additionally, the thermal niche occupied during breeding differs between biomes and, surprisingly, desert species have the second coldest thermal niche. We also demonstrate novel techniques for assessing phenological trends in baseline breeding periods using existing datasets, which could be applied globally. Based on our Australian assessment of tropical, subtropical, grassland, desert, and temperate regions we suggest that methods used to assess climate-‐induced changes from northern hemisphere research may not readily be applied to other regions and may not adequately address conservation needs.