Ecology of the Australian brush-turkey in Urban Ecosystems

Abstract

Urbanisation is one of the most extreme and long-lasting forms of human driven environmental change, which can have profound consequences for biodiversity. As cities replace natural landscapes, remaining habitat remnants are often highly fragmented and degraded, presenting a difficult challenge for urban dwelling wildlife. While many species are unable to persist in cities, others not only survive but thrive in the hostile landscape. A key area of research in urban ecology is identifying the combinations of traits that characterise successful urban exploiting species, as well as the mechanisms that allow species with disadvantageous traits to survive in highly modified landscapes. I examined the impacts of urbanisation on the Australian brush-turkey (Alectura lathami), an atypical urban exploiting species. Despite possessing several apparently disadvantageous traits, including poor flight ability and ground nesting, brush-turkeys are currently colonising cities along the east coast of Australia. I used a combination of historical data, citizen science, and field observations to quantify changes in the distribution and behaviour of brush-turkeys in urban areas. I found that the brush-turkey range has greatly fluctuated over time, however the species has greatly expanded into major cities. I found their fear behaviour is reduced in urban areas compared to their natural habitat and documented long distance dispersal behaviours within an urban landscape for the first time in this species. Additionally, I examined the potential for brush-turkeys to act as ecosystem engineers through measurements of leaf litter decomposition rate around their incubation mounds and found that their digging behaviour speeds up decomposition closer to the mounds. My results highlight that brush-turkeys are a highly successful urban colonising species, despite their disadvantageous traits, and identify some of the mechanisms that may enable the species to thrive in cities. This demonstrates the difficulties of predicting which species are likely to thrive in urban areas from their traits alone. This research also demonstrates the value of citizen science for long term monitoring of charismatic species in urban areas and the potential role of targeted, species-specific, projects. Understanding the pathways through which species adapt to urban ecosystems will improve our capacity to manage these systems and predict how they will change into the future.