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Species Profile for Whooping crane (Grus americana) Page 5 of 6
<br />Whooping cranes breed and nest in wetland habitat in Wood-Buffalo National Park, Canada. Bulrush is the dominant
<br />vegetation type in the potholes used for nesting, although cattail, sedge, musk-grass, and other aquatic plants are
<br />common. Nest sites are primarily located in shallow diatom ponds that contain bulrush. During migration, whooping
<br />cranes use a variety of habitats; however wetland mosaics appear to be the most suitable. For feeding, whooping
<br />cranes primarily use shallow, seasonally and semi permanently flooded palustrine wetlands for roosting, and various
<br />cropland and emergent wetlands. In Nebraska, whooping cranes also often use riverine habitats. Wintering habitat in
<br />the Aransas National Wildlife Refuge, Texas, includes salt marshes and tidal flats on the mainland and barrier islands,
<br />dominated by salt grass, saltwort, smooth cordgrass, glasswort, and sea ox-eye.
<br />Food Habits
<br />Whooping cranes are omnivorous, probing the soil subsurface with their bills and taking foods from the soil surface or
<br />vegetation. Young chicks are fed by their parents. Summer foods include large nymphal or larval forms of insects,
<br />frogs, rodents, small birds, minnows, and berries. Foods utilized during migration are poorly documented but include
<br />frogs, fish, plant tubers, crayfish, insects, and agricultural grains. The largest amount of time is spent feeding in
<br />harvested grain fields. In the winter, whooping cranes forage for blue crabs, clams and the plant wolfberry in the
<br />brackish bays, marshes, and salt flats on the edge of the Texas mainland and on barrier islands. Occasionally, cranes
<br />fly to upland sites when attracted by fresh water to drink or by foods such as acorns, snails, crayfish and insects, and
<br />then return to the marshes to roost. Uplands are particularly attractive when partially flooded by rainfall, burned to
<br />reduce plant cover or when food is less available in the salt flats and marshes.
<br />Movement / Home Range
<br />The whooping crane is a bi-annual migrant, traveling between its summer habitat in central Canada, and its wintering
<br />grounds on the Texas coast, across the Great Plains of the U.S. in the spring and fall of each year. The migratory
<br />corridor runs in an approximately straight line from the Canadian Prairie Provinces of Alberta and Saskatchewan
<br />through the Great Plains states of eastern Montana, North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and
<br />Texas. The complete corridor is approximately 2,400 miles (3,862 km) long by 220 miles (354 km) wide, a zone that
<br />encompasses 95% of known sightings of whooping cranes. Autumn migration normally begins in mid-September, with
<br />most birds arriving on the Texas wintering grounds between late October and mid-November. Whooping cranes
<br />migrate south as singles, pairs, in family groups, or as small flocks of 3 to 5 birds. They are diurnal migrants and stop
<br />daily to feed and rest. Local weather conditions influence distance and direction of travel, but whooping cranes
<br />generally are capable of reaching the autumn staging grounds in the north central portion of the Saskatchewan
<br />agricultural area on the second day of migration, where they remain for 2 - 4 weeks. The remainder of the migration
<br />from Saskatchewan to the wintering grounds is usually rapid, probably weather-induced, and may be completed in a
<br />week. Whooping cranes occupy winter areas for almost half a year. Although close association with other whooping
<br />cranes is tolerated at times on the wintering grounds, pairs and family groups typically occupy and defend relatively
<br />discrete territories. As spring approaches, "dancing" behavior (running, leaping and bowing, unison calling, and flying)
<br />increases in frequency, and is indicative of pre-migratory restlessness. Spring migration departure dates are normally
<br />between March 25 and April 15, with the last birds usually leaving by May 1.
<br />Reproductive Strategy
<br />Whooping cranes are monogamous, forming pairs and laying eggs as early as 3 years of age, although the average
<br />age of first egg production is 5 years. They show considerable fidelity to their breeding territories, and normally nest in
<br />the same general vicinity each year. These nesting territories, termed "composite nesting areas", vary considerably in
<br />size, ranging from about 1.3 to 47.1 km2 (0.8 to 29 mi2) but averaging 4.1 km2 (2.5 mi2). Adjoining pairs usually nest
<br />C1c N t IPA rr N - PAC E N -- 11-
<br />http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=B003 4/12/2011
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