Can environmental legislation protect a threatened apex predator across different land tenures?

[Display omitted] •Research informed policy and decision tools are vital for effective conservation.•Apex predators are critical for structuring ecosystems.•Environmental policy fails to provide protection for a wide-ranging apex predator.•Poor environmental policy is likely to lead to further decline of apex predators.•Environmental policy underestimates habitat importance in modified landscapes. Ecological impact assessments are undertaken in compliance with legislative mandates to evaluate the effects of proposed habitat modification. This task becomes complex when evaluating the impacts on highly mobile species like apex predators. Despite their importance to ecosystem function, environmental policies may inadequately protect apex predator habitat. Here we provide a case study that examines the efficacy of legislation and impact assessment tools in protecting habitat for a wide-ranging and threatened apex predator. The high resource requirements of apex predators, and their utilisation of large areas of high-quality habitat make them ideal conservation surrogates for other less resource demanding species, and as such good case studies in assessing the effectiveness of policy. The powerful owl (Ninox strenua) occurs across many landscape types throughout its distribution, including large tracts of private property and public landholdings, making this species difficult to assess through impact assessments. To examine the level of legislative protection for powerful owls, and how well their habitat use is captured, we compared GPS tracking data to environmental policy and industry impact assessment tools. We found that legislation has limited potential to protect powerful owl habitat and owls are likely dismissed from impact assessments due to their cryptic and wide-ranging behavioural traits. The existing legislative safeguards seem inadequate, and these shortcomings are likely contributing to species decline. There is a critical need for policy to be applicable to both public and private land tenure, and for legislation and impact assessment tools to incorporate research data for effective conservation and management.