To manage the incursion of weeds after the Black Summer bushfires at the Valley’s impacted colony, the Friends of the Brush-tailed Rock-wallaby received a grant from the Federal Department of Industry, Science, Energy and Resources under their Bushfire Recovery for Wildlife and Habitat Community Grants Program.
We are pleased to say that after a series of weeding activities carried out by a contractor funded by the grant, a final survey in March 2023 by Friends’ volunteers revealed that vegetation regrowth contained less weeds than expected, and it is likely these weeds are being out-competed by natural vegetation required for food resources.
Wallabies in the colony were very lucky to escape any loss of life during the Currowan bushfire, largely due to their ability to hide in deep rocky crevices in their vertical habitat. However, survival post-fire, with the loss of food resources and shelter from predators, was a very real concern. The National Parks and Wildlife Service arranged food drops that continued for six months after the bushfire. Two adult female wallabies suffered fatal face injuries within a month from the fire, possibly due to fire-related changes to their habitat.
The rugged sandstone escarpment landscape did not have weeds before the bushfire. We found that after the bushfire, there were minor weed incursions above the escarpment; these were controlled with the help of the grant.
Most of the weeds were within and below the escarpment. Hundreds of mature inkweed plants were treated with herbicide, bagged and carried from the site for disposal. Hundreds of fleabane plants were pulled prior to seeding as well as a significant amount of fireweed and various thistles. Other weeds included stinking roger, wild tobacco, farmers friend, and skeleton weed.
The Brush-tailed Rock-wallabies eat native grasses, herbs and orchids, and also feed on the foliage and fruits of shrubs and trees, as well as roots and bark. We were concerned that most of these food sources had been lost and that native vegetation would take time to recover. Some weeding had been carried out prior to the grant; however, the grant money allowed for the extension of this program.
The last survey, carried out by volunteers in March this year, indicates that the weeding helped native vegetation recover from this intense bushfire. Other factors have played a role, such as the relatively wet conditions and the nutrient-rich soil. Indeed, floral diversity appears to have increased compared to before the fire.
The post-fire vegetation has the potential to favour the survival of the wallabies with the new dense understory vegetation offering significant protection from foxes, dogs and native aerial predators. It will be interesting to observe the transformation of this post-fire composition and structure over the next few years.
Sarah Waddell
Friends of the Brush-tailed Rock-wallaby