Nesting Ecology of Greater Sandhill Cranes (Grus canadensis tabida) in Riparian and Palustrine Wetlands of Eastern Idaho

—Little information exists on breeding Greater Sandhill Cranes (Grus canadensis tabida) in riparian wetlands of the Intermountain West. We examined the nesting ecology of Sandhill Cranes associated with riparian and palustrine wetlands in the Henry’s Fork Watershed in eastern Idaho in 2003. We located 36 active crane nests, 19 in riparian wetlands and 17 in palustrine wetlands. Nesting sites were dominated by rushes (Juncus spp.), sedges (Carex spp.), Broad-leaved Cattail (Typha latifolia) and willow (Salix spp.), and adjacent foraging areas were primarily composed of sagebrush (Artemisia spp.), cinquefoil (Potentilla spp.), Rabbitbrush (Ericameria bloomeri) bunch grasses, upland forbs, Quaking Aspen (Populus tremuloides) and cottonwood (Populus spp.). Mean water depth surrounding nests was 23 cm (SD = 22). A majority of nests (61%) were surrounded by vegetation between 30-60 cm, 23% by vegetation <30 cm, and 16% by vegetation >60 cm in height. We were able to determine the fate of 29 nests, of which 20 were successful (69%). Daily nest survival was 0.986 (95% LCI 0.963, UCI 0.995), equivalent to a Mayfield nest success of 0.654 (95% LCI 0.324, UCI 0.853). Model selection favored models with the covariates vegetation type, vegetation height, and water depth. Nest survival increased with increasing water depth surrounding nest sites. Mean water depth was higher around successful nests (30 cm, SD = 21) than unsuccessful nests (15 cm, SD 22). Further research is needed to evaluate the relative contribution of cranes nesting in palustrine and riparian wetlands distributed widely across the Intermountain West. Received 14 November 2007, accepted 3 July 2008.