Habitat loss
Since European colonisation, a major threat to the survival of the glossy black-cockatoo is habitat loss – the clearing of casuarina trees in woodland areas and the loss of mature eucalypts for nest hollows.
The Riverina in New South Wales is one area in the birds' range that has suffered a major decline in population due to the removal of habitat. There has also been evidence to suggest that some glossy black-cockatoos from this region have been trapped for the illegal bird trade.
Scientists think that, to breed successfully, glossy black-cockatoos need food trees to be near their nest trees. Fragmentation of habitat reduces the chances of successful breeding.
Changing patterns of bushfires
Changes to patterns of bushfires in eastern Australia since European settlement have also contributed to the loss of habitat for the glossy black-cockatoo. Casuarina trees are very fire-sensitive and are easily killed in an intense fire. Large dead trees where the birds nest may also be destroyed in a fire.
Threats from other animals
Glossy black-cockatoos are also threatened by feral cats and possums, which raid the birds' nests. They also suffer from competition for nests from galahs and introduced honeybees.
The full impact of threats such as habitat clearing and modification on the glossy black-cockatoo is still unknown. As the bird has a relatively long lifespan, the effect of these threats may not yet be fully evident on population numbers.
In recognition of these threats, the glossy black-cockatoo is listed as vulnerable in New South Wales under the Biodiversity Conservation Act 2016. If action is not taken to stop these threats, the glossy black-cockatoo is likely to become endangered across its range in New South Wales.