Date of this Version
Urbanek R.P., and T.A. Bookhout. Nesting of greater sandhill cranes on Seney National Wildlife Refuge. In: Wood D. A., ed. 1992. Proceedings 1988 North American Crane Workshop, Feb. 22–24, 1988. Lake Wales, Florida (Tallahassee, FL: State of Florida Game and Fresh Water Fish Commission Nongame Wildlife Program Technical Report #12, 1992), pp. 161-172.
During 1987, 59 nests of 57 pairs of greater sandhill cranes (Grus canadensis tabida) were located, mainly from the air, on or near the Seney National Wildlife Refuge, Michigan, and 52 nests were ground-checked. Nests were in available palustrine classes without tree canopies. Only 19% were in Sphagnum bogs, in which most nests from other areas of the Upper Peninsula have been found. Cattail (Typha latifolia) marshes, most prevalent in the managed area of the refuge, contabed 44% of the nests, and sedge (Carex spp.) marshes accounted for 37%. Important co-dominant plant species were leatherleaf (Chamaedaphne calyculata), especially in bogs and sedge marshes, and willows (Salix ssp. Carex) in cattail and sedge marshes, sometimes forming shrub swamps. An estimated 33 of 52 clutches (63%) successfully hatched at least one chick. Thirteen clutches (25%) were believed destroyed by predators. Predation rate was least in sedge marshes, but differences in water depth, concealment, shrub cover, and distance from nearest upland were not statistically significant between sites of depredated and non-depredated nests. Nests of 30 pairs were found in an 11,600-ha intensively studied area in the eastern part of the refuge. An estimated 50 breeding pairs occur in this area, a density of 0.43 pairs/km2. The population has increased in recent history, and available nesting habitat is not a limiting factor to a larger nesting population.