Habitat and Arthropod Relationships Supporting the Red-backed Fairy-wren in the Tropical Savanna Dry Season

Abstract

Anthropogenic activities are influencing, and in many cases decreasing the tropics’ biodiversity. In Australia’s tropical savanna, mismanaged fire regimes and the introduction of nonnative species are of major concern; climate change may worsen the situation. Already very fire-prone, Australia’s wet-dry northern tropical savanna ecosystem is experiencing intensive burn regimes and also suffers from an invasive grass species which may influence the severity and frequency of fires. This study investigates relationships between fire history, vegetation, arthropods and a grassland-dwelling insectivorous bird, the red-backed fairy-wren (Malurus melanocephalus). We found that fire history predicts grass cover, which in turn influences arthropod abundance and diversity and the presence of red-backed fairy-wrens. On the basis of these finding, we argue that this species may be suitable as an indicator for ecosystem health in Australia’s tropical savanna, in the context of intensive fire regimes.