Eudocimus ruber produces a honking noise to communicate disturbances in the nest and also uses the noise in courtship. The young have a shrill cry, that they use to let parents know that they are in need of food. Touch is important during courtship. The males and females make greeting displays to one another and then wrap necks. The male produces the honking noise during courtship, while the female produces more of a squealing sound.
Communication Channels: visual ; tactile ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Many environmental and human threats exist for E. ruber. Overhunting, the harvesting of eggs and the selling of young as pets in open-markets are just three of the things affecting population sizes of E. ruber. Other crucial aspects threatening the species revolve around habitat loss. Nesting ground destruction and loss of foraging and feeding grounds are serious problems, along with heavy pollution in these now limited areas. Disturbance of breeding and foraging areas because of recreational activities, such as boating, is also a complication for colonies of E. ruber. There are laws and regulations that have been issued to protect E. ruber habitats and also gaurd the animal from hunting. However, in many areas, law enforcement is weak. In order to sustain the populations of E. ruber, pollution must be controlled in their breeding and feeding areas and people living in rural areas should be education about the bird. They are protected by the US Migratory Bird Treaty Act and are listed as Appendix II by CITES.
US Migratory Bird Act: protected
CITES: appendix ii
IUCN Red List of Threatened Species: least concern
The foraging technique that E. ruber uses sends it into many different environments to find its meals. Unfortunately, their foraging can lead the birds to beaches, gardens, yards, playing fields, golf courses, and even agricultural fields where it can disrupt the residential lives and activities of people. While no major economic downfalls or disturbances have been reported as a result of E. ruber, many consider the large number of birds in these public areas to sometimes be a nuisance.
Negative Impacts: household pest
The importance of the E. ruber dates back to the 16th century when Indian tribes would use the bright feathers for adornment and also eat the meat of the bird. Eudocimus ruber meat and eggs are still used as food by humans and the feathers continue to be used as decorative objects by people both inside and outside of the Indian community.
Positive Impacts: food ; body parts are source of valuable material
Eudocimus ruber lives among many other wading birds. While it can live harmoniously with other species, it also defends its individual space very aggressively. Other birds often steal the eggs of E. ruber, thus it must be protective of its territory. Because of its large colonial sizes (which can have anywhere from 20 to 600 nests, and sometimes even up to 2000 nests), E. ruber contributes significantly to the energy flow of organisms in the environment in which it lives. In one wetland, it has been noted to be responsible for 10% of the energy flow through the community.
This species forages for food with many other types of wading birds, such as storks and spoonbills and specifically has been seen living with Brazilian wading ducks. One reason that the species may be mutualistic in sharing feeding areas is that if it allows for a great number of birds to feed communally at its site, then it has a better chance to hide from predators among all the other birds. Also, many wading birds together stir up the shallow water and disturb the prey so that they are easier to find and catch.
Mutualist Species:
Eudocimus ruber forages for food by either probing in water with its long bill or pecking for prey items on soil surfaces. Their main diet consists of crustaceans and aquatic invertebrates. Crayfish and small crabs compose a bulk of the diet, along with aquatic insects. Frogs, mollusks, small snakes and small fish are also prey for E. ruber.
Animal Foods: amphibians; reptiles; fish; insects; mollusks; aquatic crustaceans
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Eudocimus ruber is found in northern South America, stretching from Venezuela to Eastern Brazil. It is nomadic, with seasonal shifts and migrations between different coastal locations and interior wetlands.
Biogeographic Regions: neotropical
Eudocimus ruber prefers swampy environments such as mud flats and shallow bays. It tends to reproduce and nest on dense brush-covered islands and mangroves near the mouths of rivers.
Habitat Regions: tropical ; terrestrial
Aquatic Biomes: rivers and streams; coastal ; brackish water
Wetlands: marsh ; swamp
Young E. ruber have approximately a 50% mortality rate. In general, colonies suffer from high mortality rates due to predation and lack of food. Although information on actual lifespan of E. ruber is limited, data on its North American relative, Eudocimus albus, can be used as an adequate estimate. Eudocimus albus usually lives for about 16 years in the wild and 20 years in captivity; the oldest known captive individual lived 31 years.
Average lifespan
Status: captivity: 33.2 years.
Eudocimus ruber is in the same family as spoonbills. Ibises have slightly webbed feet and a thin, down-curved bill. They fly with the bill forward and neck held straight. All ibises are long-legged and long-necked wading birds, but E. ruber can be characterized by its stunning red plumage and its glossy blue-black wing tips. This bright red color fades to pink in captive zoo birds, unless they are given a specific diet, which consists of high levels of protein and shrimp meat. Although the adults are brightly colored, the young are dull, with a grayish-brown color and white underbellies. Females and males are identical in coloration, but the male's body size and bill length are much larger. Scarlet ibises weigh between 0.772 to 0.935 g, are 55.8 to 76.2 cm long and have wingspans of 52.1 to 56.1 cm. Their metabolic rate can reach 1432 cm^3 oxygen/hour.
Average length: 55.8-76.2 cm.
Average wingspan: 52.1-56.1 cm.
Range basal metabolic rate: 1432 (high) cm3.O2/g/hr.
Sexual Dimorphism: sexes alike; male larger
Other Physical Features: endothermic ; bilateral symmetry
Average mass: 615 g.
Eudocimus ruber faces the greatest risk of predation by large cats (family Felidae) and birds of prey (order Falconiformes). Their best defense is the fact the E. ruber stays together in large groups. That way, males can use their larger size to defend their young and their female mates. The large grouping is also useful because the birds produce warning calls to warn the others of danger.
Known Predators:
Eudocimus ruber has a colonial and social breeding system. Nests are generally built close to one another with more than one per tree. This is most likely done to reduce the risks of predation. Males use displays of preening, flights, head rubbing, and a rocking motion to attract mates. A female must be cautious when approaching a male, because he may actually attack her if she does not remain in his display area. Scarlet ibises are polygynous, the males often mate with more than one female.
Mating System: polygynous
Eudocimus ruber begins visiting its colonial nesting sites by mid-September, egg-laying takes place between early November through December. The first egg is laid 5 to 6 days after copulation and there are usually 3 to 5 eggs in each nest. Eggs are not glossy, but are smooth. Incubation lasts between 19 to 23 days. Chicks fledge after 35 days and are independent in 75 days.
Breeding interval: Breeding occurs once yearly
Breeding season: Typically breeding occurs from September through December
Range eggs per season: 3 to 5.
Range time to hatching: 19 to 23 days.
Average fledging age: 35 days.
Average time to independence: 75 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average eggs per season: 2.
Young E. ruber are altricial, when they first hatch, they are helpless and cannot even hold up their heads. Both adult birds share in the responsibilities of caring for and tending to the young. Both incubate, provide food and also guard against predators. To feed their chicks adults grab hold of the bill of the young bird, which causes it to raise its head so that the parent can regurgitate into the mouth. The chick's feet develop quite fast; this allows the chicks to fledge as early as 2 weeks. By 40 days old, the young are able to fly well and by 75 days old, they are able to provide for themselves and can leave the colony.
Parental Investment: no parental involvement; altricial ; pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female)
