Date of Award
5-2018
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Biological Sciences
Committee Member
Dr. Patrick G. R. Jodice, Committee Chair
Committee Member
Dr. Robert F. Baldwin
Committee Member
Ms. Anne E. Lacy
Abstract
ABSTRACT In 2001, a reintroduced population of Whooping Cranes, known as the Eastern Migratory Population (EMP), was established in the eastern United States. The breeding range for the EMP was in central Wisconsin and the populated originally migrated to the Florida Gulf coast during the nonbreeding season. Beginning in approximately 2004-05, the wintering range for cranes shifted from the Florida Gulf coast to inland marshes in Florida. Between 2007-08 and 2017-18 the winter distribution of this population expanded north to include areas as distant as southern Indiana. To date, there has been no assessment of habitat use of the EMP across the current winter distribution. The objectives of this study were to identify factors influencing daily home range sizes of wintering Whooping Cranes in the EMP, describe habitat characteristics of areas used by cranes within their daily home range, identify the water depths and vegetation heights of used areas, and assess behavior associations with habitat. During two winters (2014-15 and 2015-16), we used radio-telemetry to track 20 and 23 groups of wintering Whooping Cranes, respectively, each for one full day. We recorded their location, behavior, and the habitat characteristics of their locations. Based on natural clustering of winter areas of Whooping Cranes, we grouped winter sites into three regions: North (Illinois, Indiana, Kentucky), Central (Tennessee, Alabama), and South (Georgia, Florida, Louisiana). We calculated home range sizes using a 95% kernel density estimate, and home ranges decreased in size from north (4.9 ± 2.8 km2) to central (3.1 ± 1.0 km2) to south (2.3 ± 0.5 km2). Home ranges in the south were also comprised of the greatest proportion of wetlands compared to other regions (south = 37%, central = 7%, north = 1%). To identify habitat characteristics of winter sites, we compared used locations to randomly generated locations within a crane’s home range separately by region. In the north region, cranes used agricultural areas more often than forests, and used areas with hydric soil that were potentially seasonally inundated during winter. In the central region, cranes selected for both agriculture and wetlands compared to forests. Cranes wintering in the south did not select habitat characteristics out of proportion to their availability within their home ranges. We also measured water depths and vegetation heights of used areas, respective to a crane. In all regions, cranes used areas with water or vegetation below the tibiotarsal joint more often than areas with deep water or tall vegetation. Lastly, we compared foraging and loafing behavior in three habitat types (agriculture, grasslands, and wetlands), both pooled and separately by region. Whooping Cranes in the north foraged more often in agriculture than in grasslands or wetlands. However, in the central region, cranes foraged equally in all three habitats, and cranes in the south foraged in either grasslands or wetlands. Loafing behavior was associated with wetlands compared to agriculture or grasslands in all three regions. The findings of this study are the first description of habitat characteristics of areas used by cranes wintering throughout the current and entire winter range of the EMP. Results from this study will inform land managers of wintering habitat use and can benefit conservation planning with respect to future reintroduction efforts of this endangered species.
Recommended Citation
Thompson, Hillary L., "Characteristics of Whooping Crane Home Ranges During the Nonbreeding Season in the Eastern Migratory Population" (2018). All Theses. 2885.
https://tigerprints.clemson.edu/all_theses/2885