Dodos and Solitaires: Raphidae

views updated

DODOS AND SOLITAIRES: Raphidae

DODO (Raphus cucullatus): SPECIES ACCOUNT

PHYSICAL CHARACTERISTICS

Dodos and solitaires were about 40 inches (100 centimeters) long and probably weighed between 24 and 40 pounds (10.5 to 17.5 kilograms). However there are some accounts of birds that may have weighed as much as 50 pounds (22.5 kilograms). Dodos were heavily built, with tiny, non-functional wings, strong legs and feet, and a large, strong hooked bill. Dodos had bare faces without feathers. The rest of the body was covered by bluish or brownish gray feathers. Rodrigues solitaires were somewhat taller and more slender than the dodo. Their heads and bills were smaller. They were brownish in color. Males were significantly larger than females. Very little is known of the physical appearance of the third species in the family, the Réunion solitaire. In fact, accounts are so vague that it is not certain they describe a member of this family at all.

GEOGRAPHIC RANGE

Dodos and solitaires are Extinct, no longer existing, but were once found on the Mascarene Islands of Mauritius, Rodrigues, and perhaps Réunion in the Indian Ocean.

HABITAT

Dodos and solitaires inhabited woodland areas.

DIET

Dodos were described as eating fruit primarily. The Rodrigues solitaire was described as eating seeds, fruit, and leaves. Both dodos and Rodrigues solitaires had an annual fat cycle during which they were fat for several months and thin the rest of the year. In the Rodrigues solitaire, individuals were fat from March to September and then thin. It was reported by one observer that two Rodrigues solitaire chicks had a fat layer 1 inch (2.5 centimeters) thick over the entire body. This fat cycle is common in many bird species of the Mascarene islands.

BEHAVIOR AND REPRODUCTION

Dodos were unable to fly, but could run quickly. They were not afraid of humans. When caught, however, a dodo screamed, causing other dodos to rush to its aid. These dodos were then caught as well. Rodrigues solitaires were territorial, pairs defended territories from other individuals of the species. Rodrigues solitaires had a courtship ritual that involved making noises with the wings. Their wing spurs were used in aggressive encounters between individual birds.

Little is known of the reproductive biology of dodos. It is likely that species built their nests on the ground, and that females laid only one egg at a time. The young were very likely altricial, hatched at an early developmental stage, blind and with few or no feathers. In the Rodrigues solitaire, nests were built from palm leaves. They were generally built on the ground. Both male and female helped incubate, or sit on, the eggs. Chicks were cared for by their parents for some time, then joined crèches, large groups of chicks.

GIGANTISM AND FLIGHTLESSNESS

Dodos and solitaires were close relatives of the pigeons and doves. Unlike existing pigeons and doves, however, they were unable to fly. They were also much larger in size. These features of flightlessness and gigantism (jie-GAN-tiz-um) likely evolved because their island habitats included no predators. In fact, flightlessness and gigantism have evolved in many other island birds. Unfortunately for dodos and solitaires, flightlessness was an extreme disadvantage when humans and other predators reached the Mascarene Islands.

DODOS, SOLITAIRES, AND PEOPLE

Dodos and solitaires were driven to extinction by human hunting. They were frequently killed for food, particularly by sailors visiting the islands they once inhabited. They also suffered from the introduction of non-native species such as pigs, cats, and rats by humans. Some dodos and solitaires were brought to Europe where they were associated with exotic islands. Because dodos were so quickly hunted to extinction, they continue to serve as symbols of extinction.

CONSERVATION STATUS

The dodo and the two species of solitaires are Extinct, due to human hunting and to the introduction of non-native species such as cats, rats, and pigs.

DODO (Raphus cucullatus): SPECIES ACCOUNT

Physical characteristics: Dodos were large birds about the size of a turkey. They had dark gray feathers on the back and somewhat lighter gray feathers on the belly. The wings were tiny and yellowish white in color. The tail was small and short, made up of five curled feathers. Dodos had large, yellow hooked bills. The face was featherless, with gray skin.

Geographic range: Dodos were found on the island of Mauritius in the Indian Ocean, about 500 miles (800 kilometers) east of Madagascar.

Habitat: The dodo inhabited woodland areas.

Diet: Dodos ate fruit. They also swallowed small stones to help with digesting food in the crop, an organ found near the throat.

Behavior and reproduction: Dodos could not fly, but were able to run quickly. When a dodo was caught, it would scream and other dodos would rush to the site, getting caught themselves. One sailor described dodos as "serene and majestic" and said that they did not run away from humans.

Dodos built nests on the ground. Only one egg was laid at a time. Judging by their size, eggs probably hatched after about thirty-seven days.

Dodos and people: Sailors traveling in the Indian Ocean caught dodos in large numbers for food. The dodo is the first recorded species that was driven to extinction by human activity.

Conservation status: The dodo is Extinct. Not only did sailors eat the dodos, but the pigs, cats, and monkeys brought to Mauritius by sailors ate large numbers of dodo eggs. ∎

FOR MORE INFORMATION

Books:

del Hoyo, J., A. Elliott, and J. Sargatal, eds. Handbook of the Birds of the World. Vol. 4, Sandgrouse to Cuckoos. Barcelona: Lynx Edicions, 1997.

Hachisuka, M. The Dodo and Kindred Birds, or the Extinct Birds of the Mascarene Islands. London: Witherby, 1953.

Perrins, Christopher, ed. Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, 2003.

Quammen, D. The Song of the Dodo: Island Biogeography in an Age of Extinctions. New York: Scriber, 1996.