Some project background and aims

Thank you all for joining the Gang-gang nests (tree hollows) project and contributing records that help us better understand this species. September is the month when Gang-gangs are most actively checking out the real estate before deciding on a hollow in which to nest. So please keep your eyes and ears open and report any hollow activity. Gangs-gangs are quite fussy in the hollows they will use. Hollow measurements from our Canberra study are

• Average height above ground = 7.5m
• Height range 5m – 9.4m
• Average hollow depth = 50.5cm
• Hollow depth range 22cm – 90cm
• Average entrance width = 13.1cm
• Range in entrance width 9cm – 20cm
• Average entrance height = 21.3cm
• Range in entrance width 12cm – 24cm
These measurements have been utilised in a design of a nest tube, about to be trialled but modelled on a successful Glossy Black Cockatoo nesting tube program on Kangaroo Island. One of the aims of this project is to check how hollow selection may vary across the Gang-gangs range and use any variation to refine the nest tube design.

We also hope that the data that you provide to this project can also test conclusions from the Canberra study that Gang-gangs tend to nest close to each other and that only around 30% of hollows will be reused in a subsequent year.

Because Gang-gangs like to nest within hundreds of metres of each other, local populations are probably reliant on having stands of suitable hollow bearing trees. This and the low re-usage rates exacerbates what is thought to a severe shortage of hollows.

Observations of the hollows of Gang-gang interest, identified in this project, will provide an indication of who else is interested in the same hollows and what this competition may mean for the Gang-gang. Once in a hollow Gang-gangs seem able to hold their own and avoid eviction by competitor species. However, of the 24 hollows utilised by nesting Gang-gangs that we have observed for more than two breeding seasons, some of these hollows have been utilised in subsequent years by Rainbow Lorikeets, Eastern Rosella, Starling, Galah, Australian Wood Duck, Brushtail Possum and Ringtail Possum.

Will be great to get more data from across the Gang-gangs range to see how consistent these findings are and to help develop measures to better conserve this heart-warming species.

Thanks you again for your contribution.

Michael Mulvaney

Posted on September 15, 2021 05:46 AM by michaelmulvaney michaelmulvaney


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