Laws such as the US Endangered Species Act require that certain decisions be based solely on scientific data. Similar statutes in Canada and Australia provide an important but somewhat contrasting role for scientific input. In the US, external peer review is a key mechanism for determining whether science appropriately informed policy. However, because peer review policies vary widely between agencies, agencies faced with politically controversial decisions may distort the peer review process e.g., by exclusion of critical reviewers.
We review how the peer review process and other avenues for scientific input have unfolded for controversial species listing and delisting decisions to draw lessons as to what guidelines are most effective in ensuring substantive review. We compare examples from the US under three administrations with the experience in Canada and Australia under administrations more or less supportive of scientific integrity. We identify areas in which several administrations have distorted scientific input in overt and subtle ways, and suggest how institutional safeguards can be strengthened to be more robust even under hostile administrations. Scientific societies such as ESA can play a key role in identifying problems and promoting policies that increase the likelihood of the use of best science for even controversial conservation decisions.