POPULATION STATUS AND GEOGRAPHIC DISTRIBUTION OF GREATER SANDHILL CRANES IN THE MID-CONTINENT POPULATION

Number and geographic distribution of greater sandhill cranes (Grus canadensis tabida) in the mid-continent population (MCP) of sandhill cranes were evaluated. G. c. tabida comprised 7 of 133 (5.3%) individuals of 3 subspecies which projects to 31,579 ± 11,661 (SE) individuals in an estimated spring MCP of 600,000 cranes. From a platform transmitting terminal (PTT)-marked sample representative of the geographic distribution of G. c. tabida, 10 of 13 (77%) settled during the breeding season in east-central Canada/Minnesota, including 4 in northwestern Minnesota, 4 in Manitoba (2 at sites near the Minnesota border), and 2 in Ontario. Three (23%) cranes settled in west-central Canada (1 in Saskatchewan and 2 in Alberta). From a sample of 16 VHF-radioed G. c. tabida representative of MCP distribution during 2003-2006, 11 (69%) and 5 (31%) originated from breeding grounds in east-central Canada and west-central Canada, respectively. Eight of 13 (62%) PTTmarked G. c. tabida settled in transition areas between the temperate prairies, and the mixed woods shield and the boreal plain ecological regions during the breeding season. Breeding distributions of PTT-marked G. c. tabida overlapped with G. c. rowani extensively in east-central Canada and Minnesota. All PTT-marked G. c. tabida that settled on breeding grounds in Canada staged in areas open to sport hunting in Saskatchewan, Manitoba, and North Dakota during fall; mean arrival and departure dates from staging areas were 7 September and 19 October (n = 12), for an average stay of 40 ± 4 (SE) days. G. c. tabida that spent the breeding season in Minnesota stayed in Minnesota during fall and experienced less exposure to hunting seasons over the fall/winter period than cranes breeding in Canada (26%, n = 3, vs. 55%, n = 8). A reduction in G. c. tabida harvest likely would be required for sandhill cranes to move beyond their current status as an occasional breeder across most of the northern plains, including the Prairie Pothole Region