LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) with heads up after dipping to feed in shallow waters. Mississippi River, Minnesota, USA, February.

Gerrit Vyn / Aerial view of oiled bird nesting colonies in Barataria Bay area of the Mississippi River delta, with oil spill containment booms attempting to prevent more oil coming ashore. These waters are contami...

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

Norbert Wu / American Paddlefish (Polyodon spathula) can sense electrical fields with long paddle, native to Mississippi River drainage system

Kirkendall-Spring / Head waters of the Mississippi River in Itasca State Park. Minnesota, USA, September 2011

George Sanker / American alligator (Alligator mississippiensis) resting on log, Hillsborough River, Florida, USA

George Sanker / American alligator (Alligator mississippiensis) walking into water, Myakka River State Park, Florida, USA

LYNN M. STONE / American White Pelican (Pelecanus erythrorynchos) in breeding plumage, Mississippi River, near East Moline, Illinois, USA, May.

LYNN M. STONE / American White Pelican (Pelecanus erythrorynchos) in breeding plumage landing on the Mississippi River, near East Moline, Illinois, USA, May.

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) sleeping on water; the bird is wintering on the Mississippi River; Minnesota, USA, February.

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) in flight over the Mississippi River. Minnesota, USA, February.

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in flight low over water. Mississippi River, Minnesota, USA, February.

LYNN M. STONE / Juvenile Trumpeter Swan (Cygnus buccinator) taking off from water. Mississippi River, Minnesota, USA, February.

LYNN M. STONE / American White Pelican (Pelecanus erythrorynchos) in breeding plumage landing on Mississippi River, near East Moline, Illinois, USA, May.

LYNN M. STONE / American White Pelican (Pelecanus erythrorynchos) in breeding plumage; note characteristic 'horn', which will drop off later in the breeding season, on upper mandible. Mississippi River, near East Mol...

Gerrit Vyn / Sunset over marsh near the mouth of the Mississippi River, Venice, Louisiana, USA

Gerrit Vyn / White ibis (Eudocimus albus) group roosting in the Mississippi River Delta wetlands, Terrebonne Parish, Louisiana, USA

LYNN M. STONE / American white pelican (Pelecanus erythrorhynchos) taking off from the Mississippi River, northern Illinois, USA, June

LYNN M. STONE / Pair of American white pelicans (Pelecanus erythrorhynchos) landing into the wind on ruffled Mississippi River, both birds in post-breeding plumage, Northern Illinois, USA, June

LYNN M. STONE / American White pelican in flight (Pelecanus erythrorhynchos) in fading breeding plumage (characteristic horn on upper mandible has sloughed off), Mississippi River, northern Illinois, USA, May

LYNN M. STONE / American White pelican (Pelecanus erythrorhynchos) in flight, in breeding plumage (note characteristic horn on upper mandible, bright orange bill, and yellow pouch), Mississippi River, northern Illino...

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) dipping their long necks to feed in shallow water. Mississippi River, Minnesota, USA, February.

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) landing on water. Mississippi River, Minnesota, USA, February.

LYNN M. STONE / Pair of Trumpeter Swans (Cygnus buccinator) in courtship display, wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) landing on the Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) wing-stretching, whilst wintering on Mississippi River, Minnesota, USA.

LYNN M. STONE / Pair of Trumpeter Swans (Cygnus buccinator) in courtship display, wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Pair of Trumpeter Swans (Cygnus buccinator) in courtship display, wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) portrait, swimming in late afternoon sun, while wintering on Mississippi River, Minnesota, USA.

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) portrait, swimming in late afternoon sun, while wintering on Mississippi River, Minnesota, USA.

LYNN M. STONE / Trumpeter swan (Cygus buccinator) family groups (probably two) in display huddle preparatory to breeding season. Wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) standing on one foot in shallow water, while wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Two Trumpeter Swans (Cygnus buccinator) landing on the Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) showing courtship aggression toward a rival, while wintering on Mississippi River, Minnesota, USA.

Gerrit Vyn / Aerial view of salt marsh in the Baratari Bay area of the Mississippi River delta. Plaquemines Parish, Louisiana. July 2010.

Gerrit Vyn / Royal Tern (Thalasseus maximus) juvenile oiled and waterlogged, as a result of the BP Deepwater Horizon oil leak, drowning in waters adjacent to a nesting colony on Queen Bess Island. Barataria Bay ar...

Gerrit Vyn / Royal Tern (Thalasseus maximus) juvenile oiled and waterlogged, as a result of the BP Deepwater Horizon oil leak, drowning in waters adjacent to a nesting colony on Queen Bess Island. Barataria Bay ar...

Gerrit Vyn / Aerial view of Queen Bess Island in the Barataria Bay area of the Mississippi River delta, with oil spill containment booms attempting to prevent more oil from the BP Deepwater Horizon leak coming ash...

Gerrit Vyn / Aerial view of oiled and containment boomed salt marsh in the Baratari Bay area of the Mississippi River delta, contaminated as a result of the BP Deepwater Horizon leak. Plaquemines Parish, Louisiana...

Gerrit Vyn / Aerial view of oiled bird nesting colonies in Barataria Bay area of the Mississippi River delta, contaminated by oil from the BP Deepwater Horizon leak in the Gulf of Mexico. Plaquemines Parish, Louis...

Gerrit Vyn / Aerial view of an oil covered island and displaced oil containment boom in Barataria Bay area of the Mississippi River delta, contaminated as a result of the BP Deepwater Horizon oil spill in the Gulf...

Gerrit Vyn / Aerial view of an oil covered island and displaced oil containment boom in the Barataria Bay area of the Mississippi River delta, contaminated as a result of the BP Deepwater Horizon oil leak in the G...

Gerrit Vyn / Oil drilling rig in Mississippi River delta salt marsh. Plaquemines Parish, Louisiana. USA, July 2010.

Gerrit Vyn / Boats and industrial development along the road to Grand Isle in the Mississippi River delta. Plaquemines Parish, Louisiana, USA, July 2010.

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) and Mallard duck, wintering on Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in flight, rusty stains on plumage are from ironoxide in water, over Mississippi River; Minnesota; USA

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) "gabbing" during courtship behaviour on Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) in winter morning mist, showing aggression during courtship behaviour, Mississippi River, Minnesota, USA, February

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) in flight over Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) two adults and two juveniles, in flight over Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) in flight over Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swans (Cygnus buccinator) showing courtship behaviour on Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) in flight over Mississippi River; Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) trumpeting in flight, flying past bare trees along Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) in flight, braking with wings and feet before landing, over Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter Swan (Cygnus buccinator) taking off with typical "run on water" launch, Mississippi River, Minnesota, USA

LYNN M. STONE / Trumpeter swans (Cygnus buccinator) in winter morning mist, stretching wings on Mississippi River, Minnesota, USA

LYNN M. STONE / Tundra / American whistling swan (Cygnus columbianus) landing on the Mississippi River, Minnesota, USA

George Sanker / American alligator (Alligator mississippiensis) climbing over a Florida red bellied turtle (Pseudemys nelsoni) on branch in water, Hillsborough River, Florida, USA, Spring

LYNN M. STONE / Trumpeter swans (Cygnus buccinator) in flight over Mississippi River, Minnesota, USA

Nick Garbutt / Open mouth of Alligator snapping turtle (Macrochelys / Macroclemys temminckii). Found in the Mississippi River and its tributaries throughout the Southeastern USA, Captive, Singapore Zoo.

Nick Garbutt / Open mouth of Alligator snapping turtle (Macrochelys / Macroclemys temminckii). Found in the Mississippi River and its tributaries throughout the Southeastern USA, Captive, Singapore Zoo.

Heidi & Hans-Juergen Koch / American Alligator (Alligator mississippiensis) group on riverbank, Florida

Heidi & Hans-Juergen Koch / American Alligator (Alligator mississippiensis) resting on riverbank, Florida

Heidi & Hans-Juergen Koch / American Alligator (Alligator mississippiensis) portrait on a riverbank, Florida

Norbert Wu / American Paddlefish (Polyodon spathula) can sense electrical fields with long paddle, native to Mississippi River drainage system

Flip Nicklin / Alligator Gar (Lepisosteus spatula) largest of all gars can grow up to 300 pounds, native to the coastal plains of the Mississippi Basin and Gulf of Mexico

Tom Vezo / American alligator in river, Texas USA

Jim Brandenburg / Two people walking across stepping stones in Lake Itasca at the headwaters of Mississippi River, Minnesota

Norbert Wu / C16 and B15a icebergs, largest icebergs in recorded history, 185 by 40 miles, contains four years of Mississippi river flow of fresh water, Antarctica