Responses by birds to fire regime and vegetation at the wet sclerophyll/tropical rainforest boundary

Abstract

Changes in fire regime have been identified as the cause of the loss of nearly 50% of wet sclerophyll forest in north Queensland in the last 50 years. In the absence of fire, rainforest invades and eventually eliminates the specialized wet sclerophyll forest biota. Bird populations and foraging behaviour were monitored in areas selected to encompass both recent and advanced rainforest invasion. Foraging guilds are discussed in relation to increasing rainforest biomass. Some species, such as the Pale Yellow Robin Tregallasia capito nana were advantaged by the expansion of rainforest. Other species, such as the Golden Whistler Pachycephala pectoralis showed no significant response, whereas the endemic subspecies of the Eastern Yellow Robin Eopsaltria australis magnirostris was clearly disadvantaged. The latter species is of particular concern because in north-east Queensland it is dependent upon wet areas adjacent to rainforest and requires open ground in which to forage. Over the longer term the White-naped Melithreptus lunatus and White-cheeked Phylidonyris nigra Honeyeaters are also threatened by habitat loss. These honeyeaters favour the wetter areas adjacent to the rainforest which are gradually being lost to the invasive process. To maximize biological diversity in the wet tropics of north Queensland, it is necessary to maintain the full spectrum of natural habitats. Fire management is therefore required to maintain the wet sclerophyll forest and its dependent fauna.