Introduction: Novel ecosystems occur when new combinations of species appear within a particular biome due to human activity, environmental change, or impacts of introduced species. Background: Managing the trajectory of ecosystems toward desired outcomes requires an understanding of the means by which they developed. To facilitate this understanding, we present evidence for the development of a novel ecosystem from a natural experiment focusing on 52 woodland remnants surrounded by maturing stands of exotic radiata pine. Results: Bird community composition changed through time resulting in a unique blend of tall closed forest and open-woodland birds that previously did not occur in the study area, nor in the region's tall closed forest or open-woodland biomes. Conclusion: Novel ecosystems will become increasingly common due to climate change, raising complex management and ethical dilemmas for policy makers and resource managers.