Scarlet macaw

Name and taxonomy

Carl Linnaeus described the scarlet macaw as Psittacus macao in 1758, in the tenth edition of Systema Naturae. The species now sits in the genus Ara, which Lacepede named in 1799. Ara is one of six genera of macaws in Central and South America. The bird belongs to the family Psittacidae and the order Psittaciformes, the parrots. It is also called the red-and-yellow macaw, the red-and-blue macaw or the red-breasted macaw.

Two subspecies are recognised, told apart by size and by the colour of the wing feathers. The South American form, Ara macao macao, has green tips on the wing coverts. The Central American form, A. m. cyanopterus, described in 1995, is larger and has blue on the wings in place of green. In Spanish the bird is the guacamayo macao, in Portuguese the araracanga and in German the Scharlachara.

Evolution and relatives

Macaws are a group of large Neotropical parrots, and the scarlet macaw is one of sixteen living species. Wikidata places the genus Ara in the subfamily Arinae, the group that holds the New World parrots. Its closest relatives are the other Ara macaws, and people often mistake it for the green-winged macaw, which is a little larger. That bird shows red feather lines across the face and lacks the yellow wing band. Like other parrots, the scarlet macaw probably descends from a line that split from the falcons and songbirds long ago.

In 2013 a team at Texas A&M University led by Christopher Seabury and Ian Tizard published the full genome of the species. From it they built genetic markers that identify individual birds from a shed feather. Those markers now help researchers track macaws across the Peruvian Amazon, where DNA breaks down fast.

Appearance

The scarlet macaw is about 89 centimetres long, and the tail accounts for a third to a half of that. It weighs about 1.2 kilograms. It carries a larger share of tail than any other big macaw. The Central American subspecies is the larger of the two.

The plumage is mostly scarlet. The upper wing coverts are yellow, the flight feathers are dark blue, and the rump and tail coverts are light blue. The undersides of the wing and tail feathers are dark red with a metallic gold sheen. Some birds show green in the wing. The tail feathers end in dark blue.

Bare white skin surrounds the eye and runs to the bill, with a few tiny white feathers on it. The upper mandible is pale horn and the lower one black, and the legs and feet are black. A young bird has dark eyes, and an adult has light yellow eyes. Males and females look alike, though a male may have a slightly longer tail and a slightly larger bill.

Habitat and range

The scarlet macaw lives in humid lowland rainforest, open woodland, river edges and savanna. It is found from sea level up to 500 metres, and in the past up to 1,000 metres. Field work in Costa Rica found the birds almost always more than 10 metres up in the canopy and rarely on the ground. Most of their food grows in the canopy, and the height keeps them away from ground predators.

In South America the range covers much of the Amazon basin and reaches east of the Andes into Peru and Bolivia. The bird is common in the Aquicuana Reserve in the Beni Department of Bolivia. It also lives on Trinidad and on the Pacific island of Coiba. The whole range spans an estimated 6,700,000 square kilometres, the widest of any Ara macaw.

In Central America it ranges from the Yucatan Peninsula through Guatemala, El Salvador, Honduras and Nicaragua. It once reached southern Tamaulipas in Mexico, but it is gone from there now. In Costa Rica it survives in pockets on the Pacific coast: the Nicoya Peninsula, Carara National Park and the Osa Peninsula. Escaped birds turn up in Florida and Puerto Rico, and a free-flying group lives around Kirkby Stephen in Cumbria, England. GBIF holds records from 48 countries, and many of those outside the Americas are captive birds.

Diet and feeding

Wild scarlet macaws eat fruit, nuts, seeds, flowers and nectar. They take fruit before it ripens, when the skin is tough and other animals cannot get in. The big hinged beak also cracks the hardest nuts, which opens a food supply that few other animals can reach. Ridges inside the beak let the bird hold a hard seed between tongue and palate and grind it. Seeds of Cnidoscolus and Schizolobium trees are thought to be the main protein source for chicks.

In parts of the Amazon, macaws and parrots gather at riverbank clay licks in the morning. The clay supplies sodium and calcium, and it is thought to bind the tannins and other toxins in unripe fruit. Insects, grubs and snails are reported now and then, but they are a very small part of the diet. On the Pacific coast of Costa Rica the birds learned to feed on planted teak and beach almond trees. Local groups planted hundreds of those trees along the coast, and the macaw population there grew sharply. Captive birds take the same kinds of food, and breeders know the diet in detail.

Behaviour and social life

The scarlet macaw is active by day and social all its life. A typical sighting is one bird or a pair crossing high over the canopy, though flocks form in some areas. Pairs fly together, feed together and preen each other, and mates show affection by licking each other's faces. Once paired, a bird is rarely alone except when one partner must stay on the eggs. At night the birds gather in flocks to roost.

The species is fairly docile for most of the year but can become aggressive when breeding. If something frightens a pair at the nest, they watch quietly until the danger passes. If the nest is directly threatened, they slip away one at a time. Like most parrots, the scarlet macaw handles food with its left foot while the right foot holds the perch. That preference is thought to reflect a stronger right side of the brain, much as handedness does in people.

Communication and senses

Scarlet macaws are among the loudest birds in the forest. Their squawks, squeaks and screams are pitched to carry many kilometres and keep the group in touch. Most contact comes as a raucous honk, but the calls vary a great deal. Captive birds mimic human speech well.

Posture carries meaning too, and a mated pair communicates by touch when the two preen each other. The birds have excellent sight and hearing. Like other parrots, they probably see colours that people cannot, which may help them judge ripe fruit. A pair calls back and forth in flight, and the calls probably help the two find each other after they feed apart.

Reproduction and life cycle

Scarlet macaws are monogamous and keep one partner for life. In Central America the season runs from about January to April. A pair breeds only every one to two years, because they will not start a new clutch while the last young still depend on them. The nest is a large cavity high in a tree, hidden by thick foliage in the upper canopy. Good holes are scarce, which holds down the number of pairs that can breed in a year. Wild pairs raise few chicks, and the weaker nestlings often die before they fledge.

The hen lays two to four white, rounded eggs. Wikipedia says she sits for about five weeks, and Animal Diversity Web gives 24 to 25 days, so the true figure probably lies between. The female does most of the incubation, and the male feeds the chicks with food he brings up from his crop. The chicks fledge about 90 days after hatching.

Young birds remain with the parents for one to two years and learn a great deal in that time. They mature at three to five years old. A typical life is 40 to 50 years, and AnAge records a captive bird of 33. Wikipedia reports captive macaws that reached 75 or even 90 years.

Predators and threats

An adult escapes most predators by its size and by flight. Snakes, monkeys, toucans and small carnivores take eggs and chicks from the nest. Jaguars and other big cats, eagles and hawks take adults and fledglings. The harpy eagle is probably the most serious threat to an adult in flight, as it is for other large canopy birds.

People are the greater danger. Poachers cut down the nest tree to reach chicks or shoot adults for food and feathers. Every felled nest tree removes a hole that took decades to form, so the harm outlasts the theft. Forest clearance breaks the range into fragments, and in Central America the bird survives only in small isolated groups.

Population and conservation

The IUCN lists the scarlet macaw as Least Concern. The wild population is estimated at between 50,000 and 499,999 birds. Most of them live in South America, where the species is still common across the Amazon. The northern subspecies is in a far worse state, with only 2,000 to 3,000 birds left, and the United States lists it as endangered. Mexico lists the species as in danger of extinction and Peru as Near Threatened.

The species is on Appendix I of CITES, which bans commercial trade across borders, including parts and feathers. Nine of the sixteen macaw species share that listing. The species keeps its Least Concern rank only because the South American range is so large and the count there so high. Conservation groups put up nest boxes where natural holes are scarce, and macaws use them. The Tambopata Macaw Project in Peru hand-rears the extra chicks that would die in the nest and releases them. In Guatemala, Tikal National Park and Laguna del Tigre protect the main nesting lowlands of the Maya Biosphere Reserve. iNaturalist holds 14,455 observations of the species.

Relationship with humans

People bred scarlet macaws in captivity at Paquime in northern Mexico in the 11th century. Diggers there found breeding pens, perches, bones and pieces of eggshell. The birds and their feathers were traded north to the Pueblo peoples of the Colorado Plateau for use in ceremony. Feathers in a tomb near Pachacamac in Peru show trade across the Andes between about 1000 and 1470.

Today only the blue-and-yellow and the red-and-green macaws are commoner in captivity than the scarlet. Zoos and breeders understand its diet, incubation and hand-rearing in detail, and that knowledge feeds back into wild releases. Stricter laws have made it rarer and more expensive, and a single bird can sell for more than $1,000. The illegal trade still earns large sums every year. Breeders now supply moulted feathers with the birds they sell, so that wild macaws are not shot for plumes.

The bird harms no one, and it earns money for forest communities through birdwatching tours. Along the Tarcoles River in Costa Rica, tour companies built a business on the macaws and helped their numbers grow. In Guatemala, community monitoring of nests supports both the birds and local tourism.

In culture and myth

In the Maya creation story, the Popol Vuh, a vain bird named Seven Macaw claimed to be both the sun and the moon. The Hero Twins shot him from his tree with a blowgun and ended his boast. In Maya and Aztec thought the macaw stood for the sun, fire and solar power. Feathers went into ceremonial dress and into burials.

In the American Southwest, scarlet macaws traded up from Mexico marked the status of the Pueblo households that owned them. Today the bird is the national bird of Honduras and a symbol of conservation in Peru. Its image probably sells more tours, stamps and souvenirs than any other bird in Central America.