Date of this Version
Stahlecker, Dale W. Availability of stopover habitat for migrant whooping cranes in Nebraska. 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. 132-40.
Four stratified random samples of 512 National Wetland Inventory (NWI) maps within the central Nebraska portion of the Wood Buffalo-Aransas whooping crane (Grus americana) migration corridor were used to evaluate the availability of wetland roost sites. Wetlands were eliminated as potential roosts if visibility was obscured by vegetation or slope, if certain human activities occurred within 100-800 ro, or if water < 30 em deep was not available. Seasonal emergent wetlands, available as roosts primarily in spring, dominated all samples, particularly in the nortb. Sixty-five percent of all wetlands >0.04 ha passed map review and 52 % passed when ground-truthed. NWI map review was a good predictor of both suitability (63 % correct) and unsuitability (73 % correct). More than one-half of all open and emergent wetlands> 1 ha passed both map and field review. Four of 6 major east-flowing rivers provide additional roosting habitat of varying quality. Stopover habitat is available throughout the migration corridor in Nebraska, though quality is best in the northern sandhill region and along major rivers. NWI map review, with adequate ground-truthing and observer experience, can provide good estimates of roost availability in open prairie where woody vegetation is limited.