Fall Migration and Mortality of Interlake, Manitoba Sandhill Cranes in North Dakota

Movements and activities of 38 color-marked and radio-tagged sandhill cranes (Grus canadensis) from the Interlake region of Manitoba were monitored in North Dakota during fall migrations in 1978 and 1979. Interlake cranes remained in North Dakota 5-7 weeks or longer, from late August through October. Individual birds spent time at as many as 5 different locations and moved in all directions and between locations separated by as much as 144 km. Most cranes frequented Kidder, Pierce, Burleigh, and Stutsman counties, whereas only 1 banded Interlake bird was located in McLean County. At least 34,000 cranes were present in Kidder and Stutsman counties during 12-15 October 1979. The mean 1st-year recovery rate from hunting for Interlake cranes was 14%, with most mortalities occurring in Pierce, Kidder, and Stutsman counties. Disturbances by hunters affected local crane movements but did not accelerate the migration of Interlake cranes from North Dakota. Crane numbers were relatively low in North Dakota during the early-September hunting seasons, but included a large portion of the Interlake population. Additional data are needed to justify that this population is not being overexploited; regulations should not be liberalized if they are expected to increase the kill of Interlake cranes.