Wood storks are the only nesting storks in the United States and our largest wading bird. They are also endearingly called "flinthead" or "ironhead" by some.
Traditionally in Austrian and German folklore, storks were said to deliver babies. These stories have now been passed on to the Americas. Wood storks are exceptionally serene animals that can live harmoniously alongside humans if left undisturbed.
Like other migrating birds, wood storks may locate their nesting grounds by recognizing geographical landmarks and sensing magnetic fields.
Perception Channels: visual ; tactile ; acoustic ; chemical ; magnetic
In the 1930's an estimated 20,000 wood stork pairs were nesting in the United States. In 1978 only 2,500 pairs were recorded and wood storks were placed on the Endangered Species List in 1984. A recent survey of nesting pairs counted 5,500 pairs (Klinkenberg, 1998). If the species grows to 6,000 nesting pairs it may be reclassified to "threatened" instead of "endangered". The best way to help the species is to preserve wetlands, limit water management, and reduce heavy metal pollution such as mercury which can be lethal to the storks (Bryan et al., 2001a).
Historically the largest American population of wood storks has been in Florida's Big Cypress National Preserve and the Everglades, but because of a decline in wetland habitat and water management, colonies seem to be migrating northward (Brooks, 2001).
Wood storks are listed as endangered on the US Federal List and are protected under the US MBTA.
US Migratory Bird Act: protected
US Federal List: endangered
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
The eggs are incubated for one month and the newborn chicks hatch weighing only 57 grams. They are completely helpless except for the feathered umbrella that the parents provide with their wings to shield them from heat and rain (Klinkenberg 1998). There is sibling competition for food and under stressful conditions only the first-born and largest will survive. During times of heavy rains, nestlings often die or are deserted by their parents (Ramo and Busto 1992).
There are no known adverse affects of wood storks on humans.
We do not have information on economic importance for this species at this time.
Wood storks and other wading birds are an integral part of the marshland food chain along with other reptilian and mammalian predators.
Adult wood storks eat small fish, frogs, mollusks, snails, insects, and aquatic invertebrates. It has been calculated that a 2.5 kilogram bird would eat more than half a kilogram of fish daily. Wood storks wade through shallow water feeling for movement and snap their bill shut when they touch a fish. Vision is not as important as touch, and the bill-snapping reflex of the stork is one of the fastest reflexes known in vertebrates, taking only about 25 thousandths of a second (Wolkomir and Wolkomir, 2001). It was also recently discovered that wood storks often leave the roost at night to catch prey or fish during nocturnal low tides. This allows them to feed without the competition of other large shorebirds such as great egrets.
Animal Foods: amphibians; fish; insects; mollusks
Primary Diet: carnivore (Piscivore )
Mycteria americana range from North America to Argentina. In the United States, wood storks nest in South Carolina, Georgia, and Florida. After breeding they may disperse north to North Carolina or west to Mississippi and Alabama.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Wood storks inhabit mainly tidal waters, marshes, swamps, streams and mangroves. They hunt for prey in shallow, muddy-bottomed banks or wetlands. Their nests are ideally constructed in trees surrounded by water to limit depredation of the eggs.
Habitat Regions: temperate ; tropical ; terrestrial
Aquatic Biomes: brackish water
Wetlands: marsh ; swamp
Other Habitat Features: estuarine
We do not have information on lifespan/longevity for this species at this time.
Average lifespan
Status: wild: 225 months.
Adults usually measure one meter tall and can have a wingspan of over one and a half meters. They have a blackish bill, accompanied with a scaly-looking, featherless head and neck which sticks out straight when flying. The majority of the birds' body is white except for the primary, secondary, and tail feathers which are black. Immature wood storks have a pale yellow bill and dull gray-colored head and neck.
Average length: 1 m.
Average wingspan: 1.5 m.
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 2500 g.
The greatest threat to wood storks are raccoons (Procyon lotor) that climb to the nests to eat the chicks. Alligators (Alligator mississippiensis) may also pose a problem to unwary birds.
Known Predators:
Wood storks are monogamous.
Mating System: monogamous
Pairs often mate for life and return to the same nest each breeding season to raise their offspring. Breeding occurs from December to April. Nests are constructed out of sticks high atop cypress, mangrove, or other trees in marshy woodlands. Wood storks nest colonially with from 5 to 25 nests in a single tree.
Females lay 2 to 4 (usually 3) eggs per clutch. Incubation lasts 28 to 32 days and the young fledge after 55 to 60 days. Woodstorks do not begin to breed until they are 4 years old.
Breeding season: December to April
Range eggs per season: 2 to 4.
Range time to hatching: 28 to 32 days.
Range fledging age: 55 to 60 days.
Average age at sexual or reproductive maturity (female): 4 years.
Average age at sexual or reproductive maturity (male): 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Average eggs per season: 3.
Both the male and female take part in nest building, incubation and the feeding of their semi-altricial young. Chicks are fed regurgitated fish and are dependent on their parents for 55 to 60 days after they hatch.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
