Crane, Grus canadensis
The Sandhill Crane, Grus canadensis is a large crane
of North America and extreme northeastern Siberia.
The common name of this bird references habitat like that at
the Platte River, on the edge of Nebraska's Sandhills in the
American Midwest. This is the most important stopover area for
the Lesser Sandhill Crane (Grus canadensis canadensis),
with up to 450,000 of these birds migrating
Adults are gray overall; during breeding, the plumage is usually
much worn and stained, particularly in the migratory
populations, and looks nearly ochre. The average weight of the
larger male is 4.57 kg (10.1 lb), while the average weight
of females is 4 kg, with a range of 2.7 to 6.7 kg across the
subspecies. The Sandhill Crane has a red forehead, white cheeks
and a long dark pointed bill. Its long dark legs trail behind
in flight, and the long neck is kept straight in flight.
Immature birds have reddish brown upperparts and gray underparts.
The sandhill crane's large wingspan, typically 1.65 to 2.1
m, makes this a very skilled soaring bird similar in style
and eagles. Utilizing thermals to obtain lift, they can stay
aloft for many hours, requiring only occasional flapping of
wings and consequently expending little energy. With migratory
flocks containing hundreds of birds, they can create clear
outlines of the normally invisible rising columns of air (thermals)
that they ride.
Crane, Grus americana
The Whooping Crane (Grus americana), the tallest North American
bird, is an endangered crane species named for its
whooping sound. Along with the Sandhill Crane, it is one of
only two crane species found in North America.
The Whooping Crane's lifespan is estimated to be 22 to 24
years in the wild. After being pushed to the brink of extinction
by unregulated hunting and loss of habitat to just 21 wild
and two captive Whooping Cranes by 1941, conservation efforts
have led to a limited recovery. As of 2011, there are an estimated
437 birds in the wild and more than 165 in captivity.
An adult Whooping Crane is white with a red crown and a long,
dark, pointed bill. Immature Whooping Cranes are cinnamon
brown. While in flight, their long necks are kept straight
and their long dark legs trail behind. Adult Whooping Cranes'
wing tips are visible during flight.
The species can stand up to 1.5 meters and have a wingspan
of 2.3 meters. Males weigh on average 7.3 kg, while females
weigh 6.2 kg on average. The body length averages about 132
These birds forage while walking in shallow water or in fields,
sometimes probing with their bills. They are omnivorous and
slightly more inclined to animal material than most other
cranes. In their Texas wintering grounds, this species feeds
crustaceans, mollusks, fish (such as eel), berries, small
reptiles and aquatic plants. Potential foods of breeding birds
include frogs, small rodents, smaller birds, fish, aquatic
insects, crayfish, clams, snails, aquatic tubers and, berries.
including wheat, barley, and corn, is an important food for
migrating Whooping Cranes.
Whooping Cranes and blue crabs depend on the health
of the Guadalupe River, which
feeds freshwater into the coastal marshes along the
Gulf of Mexico.
Photo by Mike Sloat
The Guadalupe River supplies freshwater to the coastal
marshes of the Gulf of Mexico and the wintering area
of the last
naturally occurring Whooping Crane population. The Whooping
over 4.000 km from their breeding
grounds in western Canada to winter on the coastal wetlands
near and within the boundaries of Aransas National Wildlife
Refuge in southeastern Texas. The freshwater from the
Guadalupe River is essential for the cranes and their
food source, blue crabs, but the river and coastal wetlands
are threatened by excessive upstream water use.
The survival of Whooping Cranes in Texas depends on
securing freshwater from the Guadalupe River basin and
conserving wetland habitats along the Gulf Coast (click
on the map to view our project areas). These same waters
sustain a wealth of economic activity along the Texas
coast, including commercial and sport fisheries, shellfisheries
Six Whooping Crane wintered on Granger Lake in Central TX
in 2011/2012. The group was made up of two mated pairs
and their single offspring. One adult bird flew ahead to Aransas
National Wildlife Refuge early in the season, but returned
again to rejoin it's mate and offspring. Drought conditions
in 2011 exposed much of the lake bed, creating ample feeding
grounds for this small group of cranes.
The Whooping Crane is endangered mainly as a result of habitat
loss, although whoopers are also still illegally shot despite
this being subject to substantial financial penalties and
possible prison time. The Whooping Crane is still one of the
birds in North America
Among the many potential nest and brood predators include
Black Bear, Ursus americanus,
Gulo gulo, Gray
Wolf, Canis lupus, Red
Fox, Vulpes vulpes, Lynx, Lynx canadensis,
Eagle, Haliaeetus leucocephalus, and
Raven, Corvus corax.
eagles, Aquila chrysaetos, have killed
young Whooping Cranes and fledgings.The bobcat,
Lynx ryfus, has
killed many Whooping Cranes in Florida and Texas; whether
the birds were taken on their nests or not is not specified.
In Florida, bobcats have caused the great majority of
mortalities among Whooping Cranes, including several
adults and the first chick documented to be born in
the wild in 60 years. It is believed that this is due
to an overpopulation of
bobcats caused by the absence or decrease in larger
predators (the endangered Florida panther and the extirpated
wolf) that formerly preyed on bobcats. At least 12 bobcats
have been trapped and relocated in an attempt to save
the cranes. American alligators have taken a few Whooping
Cranes in Florida.
Whooping cranes in flight and
coming into land
Video: BBC Natural History Unit
Audio: BBC Natural History Sound Library and Master Tracks