He writes:
It’s a simple question that I often get asked about an endangered species: “What caused it to decline?” but I find it to be one of the hardest to answer without giving a hand-waiving response. Determining causes of decline for a species based on data-driven conclusions rather than informed opinion is challenging because it first requires figuring out which demographic rate is depressed and then requires evidence linking it to one or more causes. Yet, to provide clear recommendations for recovering a threatened species, is there any more meaningful question to answer than what is causing it to decline?