Should a species be delisted if it depends on intensive management to remain stable? While endangered species historically presented clear-cut cases of recovery – ban DDT and the bald eagles will come back – current threats to endangered species are often more broad and best addressed through restoring and maintaining connectivity. In their recent Conservation Letters publication, Carlos Carroll and colleagues examine the issue of how much connectivity restoration is needed by a species and how endangered species that require active management intervention, in particular translocation, should be considered for delisting.
Species that are termed “conservation-reliant” are considered to be in need of constant, species-specific management in order to be sustainable. However, the use of this term constitutes a grey area when applied to delisting a species. The Fish & Wildlife Service has struggled to define how connectivity may impact a species future recovery status and whether it will preempt the need for translocation. Examples such as the Yellowstone grizzly bear, gray wolf, and wolverine provide context for looking at how connectivity requirements should or should not merit listing. Species that require high connectivity, such as migratory species like salmon, may be delisted, but only under the assumption that populations will rely on translocation in perpetuity. Even for species with lower connectivity requirements and threatened only by broad concerns such as climate change, connectivity restoration can be controversial and/or costly and therefore problematic.
Since many species that are listed require some form of intensive management and are likely to continue to need so, it remains difficult to determine what is really meant by calling a species self-sustaining. The authors argue that defining conservation-reliant species should distinguish between species that depend on human intervention to persist in the wild versus those that would thrive without humans in the landscape. Questions over the value of maintaining biodiversity and the extent to which society is willing to preserve populations as “wild” still remain unanswered, but need to be addressed more fully in order to best interpret the level of protection provided by the Endangered Species Act.
Carroll, C., D. J. Rohlf, Y. Li, B. Hartl, M. K. Phillips, and R. F. Noss. 2014. Connectivity conservation and endangered species recovery: a study in the challenges of defining conservation-reliant species. Conservation Letters. doi: 10.1111/conl.12102