Storks
Storks are large wading birds that inhabit wetlands, marshes, and grasslands, with 19 species found globally. In North America, notable species include the wood stork and the jabiru, while the white stork is well-known for its association with folklore about delivering babies. These birds vary in size, standing between 2.5 to 5 feet tall and weighing 5 to 13 pounds, with some species like the marabou boasting wingspans close to ten feet. Storks are carnivorous, foraging for insects, fish, and small animals using tactile and visual hunting techniques. They are social creatures, often nesting in colonies, and exhibit unique courtship behaviors and parental care, including feeding their young through regurgitation. Unfortunately, stork populations have declined significantly due to habitat destruction and environmental changes, leading some species to be classified as endangered or vulnerable. Conservation efforts focus on habitat protection, breeding programs, and establishing new nesting sites to support stork populations and their ecosystems.
Storks
Stork Facts
Classification:
- Kingdom: Animalia
- Phylum: Chordata
- Subphylum: Vertebrata
- Class: Aves
- Order: Ciconiiformes (wading birds)
- Suborder: Ciconiae (storks, ibises, spoonbills)
- Family: Ciconiidae (storks)
- Genus and species: Six genera and nineteen species, includingAnastomus lamelligerus (African open-bill stork),A. oscitans (Asian open-bill stork);Ciconia abdimii (Abdim’s stork),C. boyciana (oriental white stork),C. ciconia (white stork),C. episcopus (woolly-necked stork),C. maguari (Maguari stork),C. nigra (black stork),C. stormi (Storm’s stork);Ephippiorhynchus asiaticus (black-necked stork),E. senegalensis (saddle-bill stork);Jabiru mycteria (jabiru stork);Leptoptilos crumeniferus (marabou stork),L. dubius (greater adjutant stork),L. javanicus (lesser adjutant stork);Mycteria americana (American wood stork),M. cinerea (milky stork),M. ibis (yellow-billed stork),M. leucocephala (painted stork)
- Geographical location: Every continent except Antarctica; most species are found in the Eastern Hemisphere
- Habitat: Wetlands; some species require distinct wet and dry seasons
- Gestational period: Incubation averages thirty days
- Life span: Seven to thirty years, varying by species; longer in captivity
- Special anatomy: Long, slender legs; long neck; long, pointed bill
Storks are large wading birds that live near swamps, marshes, lakes, and rivers. There are nineteen species in the world. North America is home to two species, the wood stork of the southeastern United States and the jabiru of Mexico. Many species live in Africa, Asia, and Europe, and a few species also can be found in South America and Australia. The white stork is most commonly known. It summers in Europe, frequently nesting on rooftops, and is the source of the legends of storks delivering infants.
Physical Characteristics of Storks
Storks stand from 2.5 to 5 feet tall and weigh between five and thirteen pounds. The smallest species is the Abdim’s stork. The saddlebill and the marabou stork are the largest. Storks have powerful wings and a wide wingspan. The marabou’s wingspan is the greatest of all land birds, reaching nearly ten feet. Plumage can be white, gray, or black. Species with dark plumage often have iridescent shades of purple, green, or blue. Males and females look alike, but the male is larger.
Storks have long, slender legs that may be red, white, gray, or black. They have three long toes that are webbed at the base, and a shorter back toe. The strong beak is long and pointed and is straight or slightly curved.
Stork Behavior
Storks are carnivores and hunt for food in wetlands, along bodies of water, and in grassy plains. They feed on insects, worms, fish, frogs, reptiles, and small birds and mammals. The adjutant storks are scavengers, primarily seeking carrion. Many storks are tactile foragers, walking slowly through shallow water, groping with an open bill that snaps shut reflexively when it comes into contact with prey. Others are visual foragers, snatching insects or stirring the water to disturb prey, then seizing it with a thrust of the beak.
Storks do not vocalize. Instead, they communicate with bill clattering and snapping, rasping, and hissing. Nestlings make a high-pitched braying which decreases with age.
Storks fly with their necks stretched out. The legs dangle during takeoff, and then extend out behind in flight. Storks glide on thermals, soaring to high altitudes. They sometimes perform aerial acrobatics such as diving and flipping.
Some stork species migrate seasonally, others are nomadic, and some are nonmigratory. The availability of prey largely determines the migration and movement of stork colonies. Prey availability is in turn closely tied to climate and rainfall patterns. Storks will adapt the timing of migration and breeding and the choice of colony nesting site according to these climatic conditions, postponing or skipping a breeding cycle if food availability is low.
Excepting one or two species, storks live in colonies, building their nests of sticks, reeds, and vines in trees, on rooftops, or on the ground. Some mate for life; others may pair for just one season. Courtship begins with a color change of the birds’ bill, face, legs, and skin. The male performs various aggressive, ritualized displays to attract the female, who then performs appeasement displays. Both members of the pair participate in nest building, incubation, and caring for nestlings. Clutch size is two to five eggs, and incubation averages thirty days. Parents feed the young by regurgitating food into the nest. The fledgling period varies from six weeks to four months.
Conservation
Since 1950, the overall population of storks has declined by half, due to the destruction of wetland habitats from deforestation, drainage, farming and pesticide use. In 2012, the Storm’s stork was listed as endangered by the International Union for Conservation of Nature. The milky stork is vulnerable and the black-necked stork and the painted stork are near threatened. In the United States, the wood stork serves as an indicator species for the health of the Florida Everglades ecosystem. Solutions to the declining world stork populations include habitat improvement and protection, captive breeding and reintroduction of species, and artificial establishment of nesting and colony sites.
Principal Terms
fledgling period: period after hatching, during which a nestling grows flight feathers and learns to fly
indicator species: a species monitored by biologists as a means of ascertaining the health of the ecosystem in which it lives
nomadic: moving about from place to place according to the state of the habitat and food supply
scavenger: an animal that feeds on the dead carcasses of other animals
thermals: rising currents of warm air
Bibliography
Garcia, Eulalia. Storks: Majestic Migrators. Gareth Stevens, 1996.
Hancock, James. Birds of the Wetlands. Academic, 1999.
Hancock, James, James A. Kushlan, and M. Philip Kahl. Storks, Ibises, and Spoonbills of the World. Academic, 1992.
Klinkenberg, Jeff. “Coming Back on Its Own Terms.” National Wildlife vol. 36, no. 3, April/May, 1998, 52–59.