Let’s talk about Glossy Black-Cockatoos, their food and fires

By Leo Joseph January 16th, 2020

Kangaroo Island’s Glossy Black-Cockatoos are at risk due to the Australian bushfires. What are the issues?
Photo of three Glossy Black-cockatoos in a eucalypt tree.

A group of Glossy Black-Cockatoos. The female in the centre has yellow markings on her head. (Source: lostandcold, Flickr, CC BY-NC 2.0)

Black-cockatoos are among Australians’ most beloved birds. Least familiar among them is the Glossy Black-Cockatoo, Calyptorhynchus lathami.

Glossies occur from south-eastern Queensland to Mallacoota, extending west to the Riverina and Narrabri in New South Wales. They have been recorded near Paluma in the Wet Tropics of far north Queensland.

An isolated population of several hundred Glossies lives on Kangaroo Island. They are likely to have been severely impacted by the Australian bushfires.

Glossies are almost completely confined to south-eastern Australia. They live in the part of the continent known biogeographically as the Bassian subregion or province. They are emblematic of the Bassian species that the current bushfire crisis will be severely impacting.

Close up photo of a Glossy Black-Cockatoo on a thin branch eating casuarina seeds.

Glossy Black-Cockatoo feeding on casuarina seeds (Source: Brian McCauley, Flickr, CC BY-NC-ND 2.0)

A highly specialised diet

Glossies are among the most diet-specialised birds in the world. They feed almost solely on the seeds of casuarina trees in the genus Allocasuarina, not the more familiar river casuarinas such as Casuarina cunninghamiana. Their primary food trees are the species A. verticillata (on Kangaroo Island and in the Riverina) and A. torulosa and A. littoralis (just about everywhere else).

Allocasuarina trees are dioecious, meaning that male and female trees are separate individual trees. The seeds that Glossies eat are produced only by female trees. The birds spend hours every day extracting the seeds from the closed valves of these cones. Allocasuarina trees have probably not taken this kind of predation without an evolutionary fight. It’s not surprising that suitable female food trees are always patchily distributed.

Allocasuarina trees take ten years or more to produce cones and even longer to have branches thick enough to support the weight of a Glossy trying to feed. Intense bushfires can wipe out feeding habitat rather than leaving a mosaic of burned and unburned areas. This can have a truly devastating effect on the food supply of Glossies, both immediately and for years afterwards.

If bushfires had always been as intense as the current ones, we probably would not have Glossy Black-Cockatoos as we know them.

Glossy Black-Cockatoos on Kangaroo Island

On Kangaroo Island, Glossy strongholds are precisely the areas that have been burned on the north and west coasts of the island. If the birds survived the fires then their nearest unburned feeding areas may well be the less Allocasuarina-rich parts of the island’s eastern end. We just don’t know the details yet.

Glossies need tall eucalypts with suitably sized nest-hollows for breeding. On Kangaroo Island, these are principally Sugar Gums, Eucalyptus cladocalyx, and Blue Gums, E. leucoxylon. Such trees are prone to being felled in fires of this intensity. Like all black-cockatoos, the birds take several years to reach sexual maturity. They raise single nestlings.

This means that intense bushfires can have far more devastating effects on Glossies than we may at first think. This is due to the cascade of disrupted ecological interactions that severe bushfires can cause. It is simply too soon to know whether the Kangaroo Island Glossies will starve or what the eventual outcome will be. The population’s viability is likely to be hugely stressed.

The mainland population, while numerically larger and scattered in loosely connected subpopulations, will likely be suffering all the same consequences. Mallacoota is well known as a place to see Glossy Black-Cockatoos, as I was fortunate to do so last March when visiting the area.

As with so many species, we anxiously await the news that will filter through as it becomes safe to investigate burned areas and assess the real extent of these fires. We brace for tragic news.

Leo Joseph is Director of CSIRO’s Australian National Wildlife Collection and, with friends and colleagues, initiated study of Kangaroo Island’s Glossy Black-Cockatoos in 1979-80.

Find out about the impact on bushfires on Australian insects.

12 comments

  1. Thank you for this article. I’ve been desperately trying to find out more information about how our Glossies have fared for days. I’m devastated to see the extent of the fires across their range in 4 states; from Queensland, to NSW, Victoria and SA (Kangaroo Island). Knowing what a specialised diet these birds have and watching the fire map which shows the size and spread of the fires’ range and its predicted (and already known) impact on Glossy habitat and feed trees is beyond heartbreaking. I fear the worst for Glossy populations in Far East Gippsland/Mallacoota and Kangaroo Island. Are predictions any more hopeful for populations in NSW and QLD?

    Given the ferocity and intensity of the fires, is it predicted that the burnt sheoaks will die off? Have they been too badly affected to regenerate? Do you predict that as a whole, their species status information will shift from Least Concern (LC) to Critically Endangered (CE)? Please continue adding to this article with the most recent information. In broken-hearted solidarity,

    Katie

    1. Posting an amendment to previous comment: Critically Endangered should be CR, not CE as stated in earlier comment. Status information which lists this species as Least Concern is from the IUCN Red List of Threatened Species (2016).

      https://www.iucnredlist.org/species/22684749/93045002

    2. Thanks Katie, Leo says:

      Many thanks for your comment and I share all of your concerns. It is just a bit too early to know the answers to many of your questions although they are precisely the kinds of issues that will need to be ground-truthed when it is safe to do so.

      On Facebook, @blackcockatooproject posted on 14 January that on Kangaroo Island “recent fires have impacted six out of seven flocks, 59% of the feeding habitat, which supported 75% of the birds, and 93 artificial nest boxes. Immediate priorities are to conduct field surveys to assess the scale of damage (when it’s safe to do so), replace lost nest boxes and provide more food trees.”

  2. N.B. In this article we have stated that “Glossies occur from south-eastern Queensland to Mallacoota …” It would be more accurate to say “from central-eastern and south-eastern Queensland …”

  3. Thank u

  4. Hullo Leo,
    I have had the enormous privilege of reading some of your scientific journals as an ornithology student. Thank you so much for giving us an update on the status of Glossies on Kangaroo Island. I believe populations in the Blue Mountains have also been adversely affected by the fires! I live in Sydney and was first introduced to Glossies as a New South Wales Park volunteer in 2007. I have occasionally seen Glossies in various locations in the northern part of Sydney. I am not sure how many populations exist in this region and no amount of research I have done has enabled me to determine this. (The last sighting I had of Glossies was of a pair with a juvenile in Ku-ring-gai Chase National Park on the 22nd November 2019).
    I am aware that Glossies are particularly fussy about which Allocasuarina trees they feed on. Naive as this may be, I was wondering if seeds could possibly be sourced from the mainland (without compromising local populations of Glossies of course) to help out the surviving Glossies on Kangaroo Island? If so is there any way I could be of any assistance?
    With great appreciation for the work you do,
    Barbara

    1. Leo says: Thank you, Barbara for your kind words. I imagine sourcing Allocasuarina seed from the mainland might well be possible but that the first thing will be to see how much Allocasuarina has survived on Kangaroo Island. All of these sorts of issues will be among the challenges for researchers to address when it is safe to get into the fire-affected areas and see what lies ahead for these beautiful cockatoos.

  5. Superbly written and illustrated paper of, perhaps, an unfolding tragic loss.

  6. FAWNA here, the wildlife rescue group for Kempsey, Port Macquarie-Hastings and MidCoast Shires NSW. We are fielding a query about what alternate foods could be put out in the Kempsey area for GBC’s that have had so much of their habitat destroyed by fire. Knowing their pretty much exclusive diet, I am hoping that the GBC’s might make their way to where there are casuarinas seeding. For instance my property is on the Pappinbarra River south of Kempsey and our casuarinas are seeding – but they attract mostly the YTBC’s. What would you advise in this instance? I know in captivity GBCs can be persuaded to eat a variety of other seeds fruit and nuts, but I am not convinced one could persuade wild GBCs to do that. On http://www.fawna.org.au we have a Food4Wildlife and Nest Box Appeal going and Nest Boxes for GBCs might be the go to ramp up.

    1. Unfortunately we can’t provide much advice on this issue. Glossies may well search a bit further afield now. Options for providing food include sourcing fresh casuarina or considering whether they may feed on other items as they sometimes do in captivity. We’ll contact you directly to provide a couple of contact names.

  7. as of the end of January, more than 50 % evidently,. of Glossy Blacks have lost there habitat. On the eastern end of Kangaroo Island, there is alot of activity of Glossy’s mating and starting to nest. The biggest sadness is the real estate interest in the views of American River. While land is not selling, some ‘councilers’ and other older land holders and priming them selves for land sales, thus clearing Glossy and other small mammals habitat.

    1. Nationally threatened species and ecological communities is one of the nine Matters of National Environmental Significance (NES) identified in the EPBC Act, 1999 (Comm). Glossy Black-Cockatoos (Kangaroo Island) are listed as Endangered and therefore any proposed action that is being considered by a landowner or developer which may result is a significant impact to a threatened species must be referred to the Australian Government Minister for Environment for assessment. If critical habitat for a threatened species is being cleared it should be brought to the attention of the Commonwealth Govt Dept of Agriculture, Water and the Environment immediately.

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