Present address: Bush Heritage Australia, PO Box 329, Flinders Lane, Melbourne, Vic. 8009, Australia.
Collapse of an avifauna: climate change appears to exacerbate habitat loss and degradation
Article first published online: 27 APR 2009
© 2009 Blackwell Publishing Ltd
Diversity and Distributions
Volume 15, Issue 4, pages 720–730, July 2009
How to Cite
Mac Nally, R., Bennett, A. F., Thomson, J. R., Radford, J. Q., Unmack, G., Horrocks, G. and Vesk, P. A. (2009), Collapse of an avifauna: climate change appears to exacerbate habitat loss and degradation. Diversity and Distributions, 15: 720–730. doi: 10.1111/j.1472-4642.2009.00578.x
- Issue published online: 10 JUN 2009
- Article first published online: 27 APR 2009
- breeding failure;
- eucalypt woodlands;
Aim We characterized changes in reporting rates and abundances of bird species over a period of severe rainfall deficiency and increasing average temperatures. We also measured flowering in eucalypts, which support large numbers of nectarivores characteristic of the region.
Location A 30,000-km2 region of northern Victoria, Australia, consisting of limited amounts of remnant native woodlands embedded in largely agricultural landscapes.
Methods There were three sets of monitoring studies, pitched at regional (survey programmes in 1995–97, 2004–05 and 2006–08), landscape (2002–03 and 2006–07) and site (1997–2008 continuously) scales. Bird survey techniques used a standard 2-ha, 20-min count method. We used Bayesian analyses of reporting rates to document statistically changes in the avifauna through time at each spatial scale.
Results Bird populations in the largest remnants of native vegetation (up to 40,000 ha), some of which have been declared as national parks in the past decade, experienced similar declines to those in heavily cleared landscapes. All categories of birds (guilds based on foraging substrate, diet, nest site; relative mobility; geographical distributions) were affected similarly. We detected virtually no bird breeding in the latest survey periods. Eucalypt flowering has declined significantly over the past 12 years of drought.
Main conclusions Declines in the largest woodland remnants commensurate with those in cleared landscapes suggest that reserve systems may not be relied upon to sustain species under climate change. We attribute population declines to low breeding success due to reduced food. Resilience of bird populations in this woodland system might be increased by active management to enhance habitat quality in existing vegetation and restoration of woodland in the more fertile parts of landscapes.