|
| |
To listen to soundfile: click on the headphones icon
To download soundfile: click on the mp3 file name
|
|
| |
Dr Culum Brown, from the Department of Biological Sciences at Macquarie University, outlines his work on lateralisation and feeding habits in native parrots. The research looked at how 26 different native parrot species (eg. sulphur-crested cockatoos, galahs, some rosellas and budgerigars and cockatiels) responded to a variety of tasks and whether closely related species showed similar foot preferences.
|
|
| |
| The first tests related to foot preference. It was suspected that that sulphur crested cockatoos were left footed and the results confirmed this with more than 90% of individuals being left footed, but a similar preference was discovered in Major Mitchell cockatoos, with over 80% preferring their left feet. Conversely, king parrots and red wing parrots were very strongly right footed. Smaller birds, such as budgerigars, did not display these extremes of preference, showing a greater amount of diversity in this type of lateralisation. These results are borne out by the bigger picture across the species. Virtually all large bodied birds have a left foot preference. Every species of cockatoos shows this preference, the only exception being the galah with no singular preference. Other large bodied parrots, on the other hand, have a right foot preference. What is interesting here is that the large bodied native birds all show strong foot preferences, be it left or right.
|
|
|
| |
Top: Sulphur crested cockatoo; Above left: Rainbow Lorikeet; Below: Crimson Rosella | The smaller bodied parrots, however, show no strong preferences. This shift in lateralisation takes place at a body size of 31 centimetres, the larger sizes being strongly lateralised, either left or right. These findings are also borne out by what the birds eat. Those that graze on small seeds and blossoms, like lorikeets, show less bias whereas those birds that extract seeds from seed pods and rip things out of trees have strong foot preferences. The strong biases shown seem to be linked to the coordination needed between the beak, the eye and the foot in order to successfully manipulate these tougher food sources. These food sources are therefore a selective force, which explains the strong bias when these birds eat, unlike the grazing birds which do not require such precision and coordination. It seems these birds are always putting their best foot forward.
Dr Culum Brown was interviewed by Ruby Vincent for A Question of Balance. Images provided by Culum Brown. Summary text prepared by Victor Barry, May 2011.
|
|
|
|
|
| |
| Right and left footed parrots
The WingTag study with subpopulations of wild Sulphur Crested Cockatoos has extended the work by Associate Professor Culum Brown and colleagues with tame and pet parrots published several years ago. Click here forWingTag findings for Sulphur Crested Cockatoos in wild subpopulations. Image is of a current regular visitor to a northern suburb in Sydney and shows a strong left foot preference.
Image V Cobbin
|
|
|
|
|
|
|
|
|
 For more information, please contact us |
)
