BIBY TV's video: Up close with glorious Glossy Black-Cockatoos Blue Mountains

These Glossy Black-Cockatoos (ssp Calyptorhynchus lathami lathami) aka South-eastern Glossy Black-Cockatoos were filmed March - October 2022 in the magnificent Blue Mountains (NSW, Australia). All footage was collected in a favoured foraging zone – the Kings Tableland. This geological wonder is a prominent southerly spur of the Blue Mountains Range. Drone views reveal only part of the Tableland, but include the area where “Glossies” were regularly found. As does the final scene, which offers a glimpse of the western side of the same location. Most of the Tableland is part of Blue Mountains National Park and is home to several threatened plants and animals and a number of Aboriginal cultural sites. This very special place is Gundungurra Country. We acknowledge the Traditional Owners of the land and pay our respects to their Elders past and present. We are grateful for the vital contribution of First Nations People to the knowledge and conservation of Australia’s birds. The Glossy Black-Cockatoo is a relatively rare bird and is threatened throughout its range. Of the three subspecies, C. lathami lathami is the most widespread, from central southern Queensland to north-east Victoria. But this “glosses over” a contraction in distribution and a decline in numbers. In NSW, the Glossy Black-Cockatoos is listed as Vulnerable. Habitat loss and degradation can affect any bird species, but particularly those with very selective diets and more limited nesting options. Land-clearing and severe bushfire seasons remove food sources and hollow-bearing trees. For a species with a very low reproductive output (i.e. 1 egg every 1-2 years) these challenges can be disastrous. Glossies are she-oak specialists. While she-oaks are often called “casuarinas”, the category consists of the genus Allocasuarina as well as Casuarina. In parts of their range, Glossies occasionally feed on the genus Casuarina (e.g. Coastal She-oak), but 90+% of any Glossy’s diet will be seed kernels from Allocasuarina. Moreover, within a particular region they may feed on only one or two species (e.g. A. distyla, as seen here). And their fussiness even extends to specific trees and cones on those trees (i.e. more cones with seeds and cones with more seeds). Although there are odd reports of other plant types such as acacias and hakeas, HANZAB says we should treat these with caution given potential for mistaken identity (bird or plant). Indeed, the footage of the Glossy with Conesticks in the foreground hints at how this might happen. (Dandelion flower sampling by a Glossy fledgling who awkwardly came to ground surely doesn’t count.) What is more certain is that occasionally they take wood-boring insect larvae. Glossies are usually found foraging, resting, preening or allopreening (where one bird preens another, or mutual preening) in pairs, family trios or small groups (less than 10). Often it’s a case of pairs or trios along the same stretch of track, rather than a close association. Larger mixed flocks (less than 30) are seen rarely and almost always late in the day, when birds gather to drink and then roost, or early, as they begin to disperse for the day ahead. Across eight months of filming, we only observed such a grouping once (in Oct), with about 20 Glossies visible at the same time (and a portion caught on camera). Even then, pairs and trios could often be discerned. It was an impressive sight, although not quite in the realm of 100+ Yellow-tailed Black-Cockatoos at the same location. Sometimes a Glossy group consists of subadult males only, aka “bachelor flocks”. (Because of a likely sex-ratio bias at birth favouring males, females probably pair up quickly after leaving their parents.) Occasionally just a single bird is spotted and is almost certainly an adult male (whose partner is on a nest). As for identifying the sex and age of Glossies, the video provides a general guide. Plain head, solid red tail panels are reliable adult-male features. However, the odd adult female may have very little yellow on her head and only faint barring on a largely red tail (if she’s an old bird). You may also notice a yellow facial feather or two on an otherwise obvious adult male. Judging the sex of juveniles is trickier although possibly doable for some individuals. Juvenile males tend to have redder barred tails (more apparent as subadult) while a lot of yellow suggests a young female. Association with an adult pair and begging behaviour also reveal age. Juveniles are dependent on their parents for 3-4 months post-fledge and generally stay with them for a year or so. For more information on glorious Glossies, please peruse https://www.birdsinbackyards.net/species/Calyptorhynchus-lathami and https://glossyblack.org.au/wp-content/uploads/2022/02/SEGBC-Field-Guide-LR-1.pdf. Credits: Video/photos – Darren Broughton. Text – Thalia Broughton. Edited and produced by Thalia and Darren Broughton for BIBY TV.