Biological Case Against Downlisting the Whooping Crane and for Improving
Implementation under the Endangered Species Act
Abstract
The Whooping Crane (Grus americana; WHCR) is a large, long-lived bird
endemic to North America. The remnant population migrates between
Aransas National Wildlife Refuge, USA, and Wood Buffalo National Park,
Canada (AWBP), and has recovered from a nadir of 15-16 birds in 1941 to
~540 birds in 2022. Two ongoing reintroduction efforts
in Louisiana and the Eastern Flyway together total ~150
birds. Evidence indicates the U.S. Fish and Wildlife Service (USFWS) is
strongly considering downlisting the species from an endangered to a
threatened status under the Endangered Species Act (ESA). We examined
the current status of the WHCR through the lens of ESA threat factors,
the USFWS’s Species Status Assessment (SSA) framework, and other avian
downlisting actions to determine if the action is biologically
warranted. Our research indicates that WHCRs are facing an
intensification of most threat drivers across populations and important
ranges. The AWBP is still relatively small compared to other crane
species and most birds of conservation concern. To date, only one avian
species has been downlisted from an endangered status with an estimated
population of <3,000 individuals. Representation in terms of
WHCRs historic genetic, geographic, and life history variation remains
limited. Also, the lack of spatial connectivity among populations,
reliance of the reintroduced populations on supplementation, and
continued habitat loss suggest that WHCR populations may not be
resilient to large stochastic disturbances. Given that reintroduced
populations are not self-sustaining, neither supplies true redundancy
for the AWBP. Proposed downlisting before recovery plan population
criteria have been met is objectively unwarranted and reflects USFWS
inconsistency across ESA actions. Only by incorporating basic
quantitative criteria and added oversight into ESA listing decisions can
we avoid an action as misguided as downlisting the Whooping Crane
without consideration of its recovery plan criteria or ostensibly its
population ecology.