The devastating bushfires that ravaged Australia in recent years had a profound impact on wildlife, resulting in a decline in the number of species, including the Greater Glider (Petauroides volans) in the Greater Blue Mountains Area (GBMA).
Greater Gliders: An Enigmatic Marsupial
The Greater Glider, a remarkable arboreal marsupial, finds its habitat in eucalypt forests along the eastern seaboard of Australia, spanning from northern Queensland to central Victoria. This species is highly specialised, predominantly feasting on eucalyptus leaves, with a typical habitat area ranging from 1 to 3 hectares. It exhibits a strong preference for tall, wet eucalypt forests on nutrient-rich soils. Despite its resilience and adaptability, Greater Gliders are highly susceptible to the destructive forces of fires, which can have profound and long-lasting effects on their populations.
Fire and the Fragile Existence of Greater Gliders
Greater Gliders, with their dependence on eucalyptus foliage, are inherently sensitive to fires. A stark example of their vulnerability was witnessed when they vanished from the Royal National Park in New South Wales due to a fire, only to reappear after an 18-year absence. Such events underscore the challenges these marsupials face in the wake of wildfires.
The Impact of the 2019-2020 Bushfires
A study conducted by Smith & Smith delved into the repercussions of the catastrophic 2019-2020 bushfires on the Greater Glider population within the GBMA. Researchers resurveyed eight sites that remained unburnt and eight sites that were affected by the fires, all of which had existing Greater Glider survey data collected before the fires. The study sought to understand the extent of fire impact by comparing Greater Glider numbers in burnt sites before and after the 2019-20 fires. Additionally, the researchers assessed the condition of known Greater Glider habitats across the GBMA immediately after the fires in 2020 and 17 months later in 2021. Fire severity was categorised into Unburnt, Low, Moderate, High, and Extreme.
Of the eight burnt sites, two experienced a High to Extreme burn, completely scorching all eucalypt foliage. In both 2020 and 2021, no Greater Gliders were found in these two sites. However, the other six burnt sites, which experienced a Low to Moderate burn, still supported Greater Glider populations. Nonetheless, an alarming 43% mean decline in population size was recorded across all burnt sites. A linear mixed-effects model, which accounts for both random and fixed effects, was used to establish the statistical significance of the fire's impact. The results revealed a statistically significant interaction between before/after 2019 and burnt sites, with a significant decline after 2019.
Breeding Challenges for Greater Gliders
Another concerning aspect of the Greater Gliders' plight is their reproductive rate. Researchers surveyed two burnt sites, Jenolan and Wombeyan, in 2020 and 2021 to evaluate the success of Greater Glider breeding in 2020. Despite favourable weather conditions since February 2020, there was no evidence of a population increase among Greater Gliders after the 2020 breeding season. This phenomenon may be attributed to the species' comparably low reproductive output. Up to half of the adult females do not mate in a given year, and those that do reproduce raise only one offspring.
Preserving Biodiversity: A Collective Responsibility
The plight of Greater Gliders in the aftermath of the bushfires serves as a poignant reminder of the fragile balance between biodiversity and environmental disturbances. Species loss, as a consequence of factors such as wildfires, poses a significant threat to the intricate web of life that sustains our ecosystems.
To safeguard the future of Greater Gliders and countless other species, concerted efforts are needed. This includes proactive fire management strategies that minimize the extent and impact of wildfires on critical habitats. Moreover, targeted conservation initiatives, such as habitat restoration and protection, must be implemented. These efforts should be coupled with ongoing research to better understand the needs and vulnerabilities of Greater Gliders and similar species.
In conclusion, the story of the Greater Gliders in the GBMA is a stark illustration of the challenges faced by wildlife in the wake of catastrophic events like bushfires. As stewards of our environment, it is our collective responsibility to ensure the survival of these remarkable creatures and to protect the rich tapestry of biodiversity that makes our planet unique. Through research, conservation, and sustainable practices, we can work towards preserving these incredible marsupials and the ecosystems they call home.
Author: Hamish kats