The Whooping Crane (Grus americana) is one of North America’s most endangered species. There is only one wild, self-sustaining migratory population of Whooping Cranes, the Aransas–Wood Buffalo population (AWBP). The birds of the AWBP migrate 4,000 km twice each year between their nesting grounds in northern Canada and their wintering grounds on the Texas Gulf Coast. During migration, AWBP Whooping Cranes must land at suitable ponds or wetlands to forage, rest or roost. The Whooping Crane Recovery Plan, developed by federal wildlife agencies in Canada and the USA, calls for the protection and management of Whooping Crane stopover locations within the migration corridor. Although major stopover areas have been protected, many other smaller sites remain to be identified. However, the Recovery Plan offers no specific entity to identify, protect and manage the latter. To address these deficiencies in information and activity, Friends of the Wild Whoopers partnered with the United States Army Corps of Engineers (USACE) within the AWBP migration corridor to share information about Whooping Cranes and their habitat needs and identify potential stopover locations on USACE properties that could be protected and managed for cranes. This partnership identified 624 potential stopover sites on 34 USACE lakes, principally in North and South Dakota, Nebraska, Kansas, Oklahoma and Texas, with commitments to manage the habitats as resources allow.

This technical report summarizes the use of US Army Corps of Engineers (USACE) reservoirs as spring and fall migration stopover sites for the endangered Aransas–Wood Buffalo population of whooping cranes (WHCR), which proved much greater than previously known. We assessed stopover use within the migration flyway with satellite transmitter data on 68 WHCR during 2009–2018 from a study by the US Geological Survey (USGS) and collaborators, resulting in over 165,000 location records, supplemented by incidental observations from the US Fish and Wildlife Ser-vice (USFWS) and the USGS Biodiversity Information Serving Our Nation (BISON) databases. Significant stopover use was observed during both spring and fall migration, and one reservoir served as a wintering location in multiple years. Future efforts should include (a) continued monitoring for WHCR at USACE reservoirs within the flyway; (b) reservoir-specific management plans at all projects with significant WHCR stopover; (c) a USACE-specific and range-wide Endangered Species Act Section 7(a)(1) conservation plan that specifies proactive conservation actions; (d) habitat management plans that include potential pool-level modifications during spring and fall to optimize stopover habitat conditions; and (e) continued evaluation of habitat conditions at USACE reservoirs.

No abstract