Comparisons Of Migration Patterns Between Parent-reared and Costume-reared Whooping Cranes in the Eastern Migratory Population, 2012–2023

Authors

Mary Anderson, United States Geological Survey, Eastern Ecological Science Center, Laurel, Maryland and Oregon State UniversityFollow
Glenn H. Olsen, United States Geological Survey, Eastern Ecological Science Center, Laurel, MarylandFollow
Susie Dunham, Oregon State University
Hillary L. Thompson, International Crane FoundationFollow
Marianne M. Wellington, International Crane Foundation

Date of this Version

2023

Document Type

Article

Citation

Proceedings of the North American Crane Workshop (2023) 16: 182–194

Comments

United States government work

Abstract

Whooping cranes (Grus americana) have been raised and released into the Eastern Migratory Population (EMP) since 2001. Cranes either were costume-reared and learned their migration route by following an ultralight aircraft, were costume-reared and released in fall near adult cranes (known as direct autumn release), or were parent-reared by captive adult whooping crane pairs and released in the fall near adult whooping cranes. Compared to costume-rearing, parent-rearing encourages conspecific learning prior to release, but needs further research to understand how it may influence post-release behaviors including migration. This study compared the migratory timing and length of parent-reared whooping cranes and ultralight-led, costume-reared whooping cranes in the EMP during 2012–2023. Using GPS data from satellite transmitters, we determined when cranes were migrating or stationary and categorized movements as summering, stopover (2 or more relocations in an area that spanned overnight hours), migratory, or wintering. No differences in timing, distances, or duration of migration were detected during the spring between parent-reared cranes and costume-reared cranes. However, parent-reared cranes migrated shorter distances (W = 65, P = 0.02), migrated shorter durations (W = 61, P = 0.04), and completed migration earlier in the year during the fall (W = 65, P = 0.02). These results were expected given that costume-reared-cranes were taught specific routes with numerous stopovers to Florida during ultralight-led migrations while parent-reared cranes experienced a greater variety of wintering locations and migratory routes from other cranes. Individual cranes from both rearing groups (parent and costume-reared) sometimes followed different migration routes from year to year. These results suggest that rearing and release techniques have some effects on post-release selection of migratory routes but not the timing of migratory initiation. Future work should include comparisons with direct autumn release costume-reared cranes.