Abstract:

The Mid-continent Population (MCP) of sandhill cranes (Grus canadensis) breeds across wide areas of central and northern Canada, the northern United States (Minnesota and Alaska) and over extensive parts of northeastern Russia and winters in the south-central and southwestern United States and northern Mexico. The MCP is hunted legally over wide areas of midcontinent North America and Alaska. Sandhill cranes have the lowest annual recruitment rate among North American game birds so detailed insight is required into susceptibility to harvest and other factors. Effective management of the MCP requires refined knowledge of the breeding distribution of subspecies and subpopulations, chronology of their use of fall staging areas and wintering grounds, exposure to and harvest from hunting, and annual recruitment rates by subpopulation. To address part of information needs, we tagged 153 sandhill cranes with Platform Transmitting Terminals (PTTs) during 22 February–12 April 1998–2003 in the Central and North Platte River valleys of south-central Nebraska where virtually the entire Population stages in March. Trapping methods were designed to provide a representative sample of the MCP with regard to geographic distribution, chronology of use of fall staging areas and wintering grounds. We monitored PTT-tagged sandhill cranes from their arrival to departure from breeding grounds, during their fall migration, and throughout winter using the Argos satellite tracking system. Genetic sequencing of mitochondrial DNA (mtDNA) from blood samples taken from each of our sample of tagged cranes allowed determination of the percentages of G. c. canadensis and G. c. tabida present in the MCP. We have followed up with additional tagging of cranes with GPS transmitters focusing our efforts primarily on cranes breeding in Russia and western Alaska to gain more detailed insight into the life histories of cranes in this subpopulation. This seminar will focus primarily on information obtained on the MCP through use of satellite telemetry to provide MCP crane managers with increased insight when seeking to improve harvest management, initiate conservation efforts, or addressing other issues concerning the population.

About the Speaker:

Gary Krapu was born at Oakes, North Dakota and grew up on his family’s farm in southeastern North Dakota. By the age of 10, waterfowl and prairie wetlands had become his passion. He completed his undergraduate studies at North Dakota State University in 1966 and moved on to graduate studies at Iowa State University where research for his Ph.D. Dissertation focused on feeding ecology of pintails during reproduction while working under the supervision of Milton Weller. Gary spent his entire 42 year career at the USGS Northern Prairie Wildlife Research Center. He retired in 2011 but maintains an office at the Center and continues to conduct research on cranes while in an Emeritus status.

Waterfowl continued to be a major focus of Gary’s research throughout most of his career. Among major topics addressed in waterfowl studies were nutritional requirements of breeding waterfowl, role of nutrient reserves on reproduction, role of staging areas in life cycles of waterfowl, wetland habitat requirements of breeding waterfowl and their broods, annual recruitment rates and causes of duckling mortality in prairie-nesting ducks, and factors regulating timing of termination of breeding in temperate- nesting waterfowl. He has authored 100+ scientific papers and several chapters in books on waterfowl and cranes.

Dr. Krapu began studies of sandhill cranes in the Central Platte River Valley of Nebraska in 1977 and in following decades expanded his research to other parts of the species’ range. The 30+ peer-reviewed scientific papers he has authored on sandhill cranes include two Wildlife Monographs, the first entitled Geographic Distribution of the Mid-continent Population of Sandhill Cranes and Related Management Applications published in 2011. This monograph focused, in part, on defining the geographic distribution of 4 subpopulations of MCP during fall migration and winter to provide crane managers with increased insight into the sources of cranes being harvested. A second Wildlife Monograph entitled Spring Staging Ecology of the Mid-continent Sandhill Crane Population with an Emphasis on the Platte River Valley, Nebraska was published in 2014 and examines the role of spring staging areas to the MCP. A third monograph in preparation focuses primarily on the estimated 23% or 140,000 cranes of the MCP that breed in Russia. Gary has received several awards for his work including the Meritorious Service

Award from the U.S. Department of Interior, elected a Fellow in the American Ornithologists’ Union, recipient of the Ducks Unlimited International Wetland Conservation Achievement Award, and the L. H. Walkinshaw Award of the North American Crane Working Group. These awards were received primarily in recognition of his contributions toward guiding the direction of waterfowl and sandhill crane research, conservation and management in North America over the past several decades.

Gary served on committees of several graduate students and participated in numerous collaborative research efforts with other scientists including biologists from other nations while seeking information needed to help guide conservation and management of cranes and waterfowl. He served as the biological expert witness for the U.S. Government in court cases where the designation of critical habitat for whooping cranes in the Platte River ecosystem was challenged and where planned federal water projects threatened habitat important to migratory water birds breeding in the Prairie Pothole Region.