One of the surest signs of a changing climate is being provided by birds. There is now irrefutable evidence from the northern hemisphere, based on observations of bird migration, that species such as migratory ducks are shifting their wintering grounds northwards in response to warming weather patterns. In Australia there is also mounting evidence of similar trends with one study (Smith et al, 2012) noting … “We examined a dataset of first arrival and last departure dates for breeding and non-breeding migrants at Blaxland, west of Sydney, from 1980 to 2011, for temporal trends and for relationships with climatic variables. The 16 species whose arrival dates were analysed have been arriving, on average, 4.4 days earlier per decade. Six species are now arriving significantly earlier than in the 1980s and no species is arriving significantly later.”
Locally we are also experiencing some changes in bird movement patterns, although the extent to which they are being influenced by climate change is less clear. Other factors, such as land use intensification, are also playing a role.
The Black Kite Milvus migrans, is one of Australia’s most common raptors. Anyone who has travelled to northern Australia will probably recall large flocks of these birds. They are most commonly associated with human habitation, sometimes gathering in their hundreds near abbatoirs and rubbish-tips. Over the past decade they have been an occasional visitor to our district, usually as singles or groups of a few birds at a time.
Yesterday afternoon I was astonished to see a flock of ~40 circling high above the broiler farm complex near Joyce’s Creek. This is by far the largest congregation I’ve witnessed in our area, but consistent with other recent observations in central Victoria. A single Black Falcon and a couple of Whistling Kites were associating with the flock.
Reference: Smith, P., and Smith, J. (2012). Climate change and bird migration in south-eastern Australia. Emu 112 (4) 333-342.

























