Effective conservation requires clear objectives and prioritizing actions, not places or species

In their recent article, Jenkins et al. (1) identify “priorities for future conservation investment” in the continental United States. To find these priority areas, the authors weighted species from six taxa by their range size and level of protection, summing the weighted maps to derive maps of priority scores. Such scoring systems defy contemporary planning approaches, and have repeatedly been shown to identify priorities that are biologically ineffective and economically inefficient (2).

Three decades of evolution in the theory and practice of conservation planning has led to four critical lessons. First, priority setting requires explicit and defensible objectives (2); for example, minimizing the cost of acquiring land to protect a minimum proportion of each species’ range. The locations highlighted by Jenkins et al. (1) simply contain the largest number of relatively unprotected and restricted-range species, and it is unclear whether protecting these locations would achieve any particular objective.

Second, conservation plans should prioritize actions, not species or places (2). Prioritizing species does not clarify what actions should be taken to avert species’ declines. Jenkins et al. (1) refer to protected areas, yet they also mention restoration and easements. Each of these actions has different costs and probabilities of success. Ignoring the costs and feasibilities of these different actions results in inefficient plans (2).

Third, conservation plans should consider at least some of the economic, political, and social constraints on actions. Jenkins et al. (1) note that land with high numbers of endemics in the east has the lowest levels of protection because that land is most valuable for agriculture and development. Indeed, this spatial variation in costs can and should be explicitly considered when prioritizing actions to save those species. Moreover, recent research allows planners to include local social enabling factors that make protection more likely to be funded, or to succeed (3).

Finally, a central principle of conservation planning is that decisions account for the composition of species assemblages across sites (“complementarity”; see ref. 4). Considering complementarity ensures that protection is directed at all species, not simply those colocated in species-richness hotspots. Jenkins et al.’s (1) finding that each of their six taxa has strongly divergent patterns of richness indicates that complementarity could be particularly important for conserving US species.

Mapping the patterns of species diversity is an important part of designing conservation plans and we commend Jenkins et al. (1) for bringing together up-to-date and high-resolution data on species’ distributions. However, identifying conservation priorities requires considering the points we highlight above, such as recent analyses that have identified priority investments for conservation actions across the continental United States (5). In particular, in direct contrast to Jenkins et al. (1), Withey et al. (5) identified priorities for conserving species in the central and western United States. Contrasting these studies shows how simplistic analyses can misinform investments, and how factors, such as socio-economic variation, can strongly influence the return on conservation investment.