Let’s talk about Glossy Black-Cockatoos, their food and fires
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.
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.
January 17, 2020 at 9:19 am
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
January 17, 2020 at 12:20 pm
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
January 17, 2020 at 12:43 pm
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.”
August 9, 2022 at 1:22 pm
Hey Katie, just thought you would like to know we have a very large population of Glossys here in the South Coast NSW. We see them nearly every day on our walks feeding on the Casuarinas 🙂
January 17, 2020 at 4:22 pm
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 …”
January 17, 2020 at 10:13 pm
Thank u
January 18, 2020 at 9:03 pm
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
January 20, 2020 at 12:09 pm
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.
January 19, 2020 at 1:30 pm
Superbly written and illustrated paper of, perhaps, an unfolding tragic loss.
February 8, 2020 at 4:46 pm
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.
February 10, 2020 at 8:59 am
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.
February 8, 2020 at 7:45 pm
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.
February 12, 2020 at 6:39 pm
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.
August 8, 2020 at 1:32 pm
We have seen more Glossy Blacks this year than past years where I live at Ocean View in Qld. I have lived here for almost 10 yrs and saw my first pair a few years ago. I see them most mornings and a couple of weeks ago counted 15 in one group. I was unaware that they only eat a particular species of casuarina. We have several growing in our back yard and the Glossy Blacks often feed on one particular tree.
September 23, 2020 at 8:19 am
Today 23/9/20 there are about 7 or 8 of these cockatoos at the very top of some tall pines near my farmhouse near Parilla in the Murraylands. They mostly seem to have yellow on their heads. Not sure if they are staying or just moving through.
September 7, 2022 at 1:47 pm
I’m presently at South West Rocks on the Mid North Coast of NSW. I used to live here and remember the glossies feeding on the Casuarinas on the Monument Hill walk.
I’m visiting now and walked Monument Hill the other day. No glossies, but no seeds either. Probably not the right time of year. Hope there are other feeding sites in this district.
February 27, 2023 at 8:21 am
K Graham
I am at Gum Scrub in the Hastings LGA. I have Glossies feeding on my Allocasuarina trees.
I am letting them come up naturally but I was wondering with the seeds, as they are dioecious do you need both, for the seeds to produce a tree that the Glossies will feed off ?
The Glossies seem to only choose selected trees to feed off, on the property. If there was a wider spread of Glossy feed trees on properties would that help them ?
Do Glossies remember what trees they were able to get a feed from and go back again to that same tree and at what intervals ?
How often do the trees produce cones ?
How do Allocasuarina trees respond in a Bushfire ?
Is there anything more we could do to assist these beautiful birds with the trees and plantings ?
Many thanks