Date of this Version
Peterson, Melvin K., and Roderick C. Drewien. Harts Basin, Colorado: a spring migration stopover area for Rocky Mountain sandhill cranes and whooping cranes. In: Urbanek RP, Stahlecker DW, eds. 1997. Proceedings of the Seventh North American Crane Workshop, 1996 Jan 10-13, Biloxi, Mississippi. Grand Island, NE: North American Crane Working Group. pp. 153-56.
Greater sandhill cranes (Grus canadensis tabida) from the Rocky Mountain Population (RMP) and whooping cranes (G. americana) reared by RMP foster parents were monitored during 1980-95 at a traditional spring migration stopover at Harts Basin in western Colorado. Counts during March and April 1986-93 showed that a mean of 10,656 RMP sandhill cranes stopped annually for 1 or more nights en route from their spring staging area in the San Luis Valley, Colorado, to summer grounds. More than 96% stopped between 11 March and 10 April. Count data indicated that > 50 % of the RMP stopped annually at Harts Basin during spring migration. Ninety-three whooping crane sightings were recorded during 16 years (X ~ 5.8, annual range 2-12) with peak migrations (77.4%) during 1-10 April. Most whooping cranes (88.2%) migrated in April through Harts Basin during the latter half of the sandhill crane migration period. Managing human disturbance near roost sites at Fruit Growers Reservoir between 10 March and 20 April would help ensure continued long-term use of the area by migrants.