the Wilson's phalarope and the Eared grebe. The Wilson's phalarope spends several months
at the Great Salt Lake during the summer, feasting on the abundant brine flies and brine shrimp,
before its 3,000 mile non-stop migration to South America. The Eared grebe also relies upon the huge concentrations of
brine flies and brine shrimp that inhabit the Great Salt Lake, in order to build and replenish fat deposits necessary for their
fall migration to Mexico and the Gulf of California.
WILSON'S PHALAROPE IDENTIFICATION
| The Wilsonís phalarope
(Phalaropus tricolor) is a
strikingly patterned shorebird which can be
characterized by its slender needle-like bill, pearl-gray
head and back, white under parts, black strip through its
eye and down its neck, and chestnut markings on its breast
and back. Unlike the other species of phalaropes, the
Wilsonís phalarope does not possess fully lobed toes,
therefore it rarely swims.
DOES THE WILSON'S PHALAROPE LIVE?
|The Wilsonís phalarope is
inland species, nesting on the grassy
borders of shallow lakes, marshes,
reservoirs, and gathers at inland
saltwater and alkali sites before its fall
migration. These habitats that the
Wilson's phalarope occupies makes
them vulnerable to predators, such as
breeds primarily in the wetlands that are scattered
throughout the interior western North
America and winters in South America.
shrimp, mosquito larva, brine flies and other invertebrates, which they capture by spinning their body in
circles in the water while, at the same time rapidly stabbing at the surface with its needle-like bill.
PHALAROPE EXHIBIT SEX ROLE REVERSAL
The Wilsonís phalarope is unusual among birds in that the sex roles are reversed. The
female not only has the brighter plumage but also arrives first on the breeding ground and
advertises and competes for a mate. Also, the male phalarope has to construct the nest,
incubate the eggs, and tend for the young.
WILSON'S PHALAROPE MIGRATION
Around mid-June, female Wilsonís phalaropes begin arriving in large concentrations to the
shores of the Great Salt Lake from Canada. Male phalaropes typically arrive at the Great Salt
Lake two weeks later than the females. It has been estimated that 50% of the world's population
of Wilsonís phalarope stop at the Great Salt Lake during their fall migration. The annual
phalarope survey was conducted on July 29, 1998 and researchers counted approximately
300,000 birds which is approximately 100,000 more birds than previous years.
|Feasting on the rich abundance
double their weight during their visit to the
Great Salt Lake. Typically, the Wilsonís
phalarope departs from the Great Salt Lake in
late July through August and fly
approximately 54 hours non-stop, to reach
their wintering grounds in the inland saline
lakes of Argentina,
|The Eared Grebe (Podiceps
nigricollis) is a
small, stocky-bodied diving bird, which can
be characterized by it's slender bill and
neck, slate-gray head and back with a
contrasting white chin, and whitish flanks
and belly. During the breeding season, the
Eared Grebe's plumage undergoes various
changes, which consist of a black crested
head with golden ear tufts, and a black
neck and back with reddish flanks.
aquatic waterbird. The Eared Grebe's plumage is thickly covered with waterproof feathers,
which allows the Eared Grebe to sink easily and reduce its buoyancy by compressing its
plumage and internal air reservoirs in order to capture prey and escape predators. Unlike most other diving birds, the
Eared Grebe doesn't posses webbed feet, but lobed feet, which are used to propel itself through the water. Also, the
anatomy of the Eared Grebe, which is characterized by small wings, short tail, and leg placement towards the back end of
the body, makes it difficult for the Eared Grebe to maneuver on land and engage in flight.
WHERE DOES THE EARED GREBE LIVE?
The Eared Grebe primarily inhabits shallow lakes, marshes, reservoirs, and gathers at inland
saltwater and alkali sites before it's fall migration. Eared Grebes are typically found on all the
continents, except Antarctica. The Eared Grebe, primarily breeds in the marshes and wetlands
of the interior North America and winters along the Pacific and Gulf coasts.
DOES THE EARED GREBE EAT?
|The Eared Grebe feeds almost
aquatic insects and small crustaceans;
including brine shrimp, plankton, and
other invertebrates, which they catch
by diving underwater and capturing prey with
their slender bills. It is noted that Eared
Grebes have become adapted somehow, in order to to
be able to ingest large quantities of brine
solution and survive. Possible explanations
suggest that the Eared Grebe's massive
tongue, when feeding, releases the saline solution in it's
beak back into the lake, leaving only shrimp to swallow.
EARED GREBE MIGRATION
Towards the end of June, the Eared Grebe begins arriving in large concentrations to the
shores of Great Salt Lake, from the interior marshes and wetlands of North America. During
1994, researchers counted approximately 400,000 Eared Grebes, which is the second largest
staging population in North America. Feasting on the abundance of brine shrimp and
other invertebrates, the Eared Grebe often becomes so obese during their stay at the
Great Salt Lake, that they are unable to fly. When this happens, the Eared Grebe remains
in order to rebuild their breast muscles, and to molt which are necessary actions for a successful
migration. As winter approaches and the brine shrimp populations begin to dwindle, the Eared
Grebe departs from the Great Salt Lake and migrates to their wintering grounds along the
Pacific and Gulf coasts.
RETURN TO TOP OF PAGE
Sorensen, Ella. (1997). "A
Grebe Called Hope". Seductive Beauty of Great Salt Lake.
Gibbs-Smith: Salt Lake City.
Sorensen, Ella. "Wison's
Phalarope." The Salt Lake Tribune. Aug. 25, 1998.
pgs. C1 & C6.
Salt Lake Ecosystem Project
Wharton, Tom. (ND) "The Great
Salt Lake: Utah's Amazing Inland Sea". The Salt Lake
Tribune. pgs. 12-13.
Wilson's Phalarope picture
Salt Lake and Mar Chiquita Cordoba pictures
Additional sites of interest:
Hemisphere Reserve Network
Ford's virtual fieldtrip, Westminster College professor
Migratory Bird Center
Grebe, winter distribution map
Grebe, summer distribution map
Division of Wildlife Resources
Department of Natural Resources