In 2006, a widespread fire in the Bookmark Biosphere Reserve, South Australia, consumed over one-third of the old growth mallee considered to be the prime habitat of the endangered Black-eared Miner Manorina melanotis. Since 2008, the species has been observed foraging and breeding in the fire-altered area. To verify whether food resources can explain the Black-eared Miners' presence in habitat consisting of early seral stages, we examined if a link could be found between the foraging behaviour of the Black-eared Miner and its invertebrate food resources.
Foraging behaviour of Black-eared Miners was sampled opportunistically using focal observations. All potential invertebrate food resources were sampled using micro-pitfalls, malaise traps, beating trays, sweep nets and active searches. Black-eared Miners devoted significantly more time to foraging in long unburned (hereafter referred to as unburned) rather than in recently burned habitat. No differences in invertebrate abundance, species richness or diversity were found between burned and unburned habitats. However, differences in community composition between habitats were found. Lerp, which is a sugary protective covering of particular insect larvae, is an important food source for the Black-eared Miners, and was found more in the unburned natural habitat.
We found that Black-eared miners may be more adaptable than previously thought when it comes to utilization of burned habitat. Still, this study reaffirms the importance of unburned habitat for Black-eared Miners.