REINTRODUCTION TECHNIQUES: POST-RELEASE PERFORMANCE OF SANDHILL CRANES (1) RELEASED INTO WILD FLOCKS AND (2) LED ON MIGRATION BY ULTRALIGHT AIRCRAFT

Authors

RICHARD P. URBANEK, U.S. Fish and Wildlife Service and International Crane Foundation, Necedah National Wildlife RefugeFollow
JOSEPH W. DUFF, Operation Migration
SCOTT R. SWENGEL, International Crane Foundation
LARA E. A. FONDOW, International Crane Foundation

Date of this Version

2005

Document Type

Article

Citation

Urbanek, R.P., J.W. Duff, S.R. Swengel, and L.A. Fondow. Reintroduction techniques: post-release performance of sandhill cranes (1) released into wild flocks and (2) led on migration by ultralight aircraft. In Chavez-Ramirez, F, ed. 2005. Proceedings of the Ninth North American Crane Workshop, Jan 17-20, 2003. Sacramento, California: North American Crane Working Group. Pp. 203-212.

Comments

Reproduced by permission of the NACWG.

Abstract

Two methods of reintroducing a migratory population of whooping cranes (Grus americana) were tested with costume/ isolation-reared juvenile greater sandhill cranes (G. canadensis tabida): (1) release into wild flocks during autumn staging and (2) leading on autumn migration by ultralight aircraft. Birds in the first group were released singly, and all integrated quickly into the wild flocks and adopted similar behavioral patterns. Birds in the second group were led to winter on an inland site on the Gulf Coast of Florida. Most of the birds led by ultralight aircraft remained in their juvenile cohort through the following summer and wandered more extensively than the birds released into autumn staging flocks. Both groups demonstrated adequate survival, return rates to Central Wisconsin (8/8 for autumn release, 9/11 for ultralight-led migration), foraging, roosting, social association, and human avoidance behaviors. Both of these techniques could be effective in reintroducing a migratory population of whooping cranes.