FireFire

Fire

Increases in fire frequency, intensity and scale pose a significant threat to avian communities. Where fire intervals are too short, flowering events and maturation of nectar-rich plant species may be reduced, resulting in a reduction of foraging resources for nectarivorous birds (Woinarski and Recher 1997). This is of particular concern in coastal New South Wales and in central Victoria where there is increasing residential and industrial development in close proximity to Swift Parrot habitat. Such developments are required to comply with new fire safety regulations involving clearing trees within fire protection zones and undertaking hazard reduction burns. With an increase in the human population residing adjacent to Swift Parrot habitat and increased accessibility to bushland areas, an increase in the incidence of accidental and deliberate fires will incrementally impact on Swift Parrot values across its range.

Fires may kill canopy trees but these (and hollows) may persist as dead stags. Fires may also lead to hollow formation (or a change in dimensions of existing hollows) in surviving trees or destroy hollow-bearing trees. Frequent fire may alter natural wildfire tree recruitment processes and hence dictate future availability of hollows (Woinarski and Recher 1997). Fires may also cause the collapse of hollow bearing trees, thus reducing hollow availability into the future. One long-term study looked at survival of nest trees over time and found that unburnt trees mostly survived but that nearly half of the trees burnt with cavities collapsed within six months of burning (Stojanovic et al. 2015). Further, hollow loss in the aftermath of fire may act to limit the short term abundance of nest sites in burned habitats. Stojanovic et al (2015 ) showed that of 63 per cent of known nest hollows that were burnt in a wildfire collapsed, reducing the availability of nests in an important breeding site.

In 2013 and 2019, fires in Tasmania impacted large areas of remaining breeding habitat. While difficult to accurately quantify the combined impact has been immense relative to the area of remaining breeding habitat and replacement time. In 2019–20, following years of drought (DPI 2020), catastrophic wildfire conditions culminated in fires that covered an unusually large area of eastern and southern Australia. The bushfires will not have impacted all areas equally: some areas burnt at very high intensity whilst other areas burnt at lower intensity, potentially even leaving patches unburnt within the fire footprint. However, an initial analysis estimates that between 10 and 30 per cent of the distribution range of the Swift Parrot was impacted to some degree. This type of event is increasingly likely to reoccur as a result of climate change.