Scarlet macaws have the widest range of all macaw species, they are found from southern Mexico to Central South America. Two subspecies of scarlet macaws exist, Ara Macaocyanoptera from Mexico to Costa Rica which has a large yellow band on the wings, and Ara Macaomacao from Costa Rica to Central South America with very little yellow on the wings. The principle threats to scarlet macaws, and in fact most macaw and parrot species are loss of habitat and poaching of nestlings for the live bird trade. These two threats together have resulted in declining numbers of scarlet macaws throughout their range and the species is now extinct in El Salvador. In 1988 the Scarlet Macaw was listed on Appendix 1 of CITES (Council on the International Trade of Endangered Species), banning all trade in scarlet macaws in CITES signatory countries.
The remaining Scarlet Macaws in Costa Rica are found in only two viable populations, both on the Pacific coast. The population found on the Osa Peninsula is the largest and consists of approximately 700 scarlet macaws.
The second viable Costa Rican Scarlet Macaw population is our study population found in the Central Pacific Conservation Area, an area which includes Carara National Park and Guacalillo Mangrove Reserve. Several additional relict populations exist in other areas of Costa Rica, including Palo Verde National Park and La Amistad Conservation Area, however they consist of few individuals.
In both of the main Costa Rican populations, the Scarlet Macaw coexists comfortably with humans. Although clearly dependent on the protected areas within their range, the Central Pacific Scarlet Macaw population is often observed in highly modified habitats, such as agricultural, grazing lands or close to human dwellings. However despite the fact that the population has adapted to habitat alteration to some degree, the primary threat to the population is the disturbing level of nestling poaching in Costa Rica.
Scarlet macaws are secondary cavity nesters, they nest in naturally formed tree holes. Trees with soft wood, such as Ceiba (Ceiba Pentandra) and Gallinazo (Schizolobium Parahybum) will form cavities more quickly than hard wood trees, so are important for the species. Many nests are found in old or dead trees where branches break off and cavities are formed when rotting wood is exposed.
Many animals including iguanas, parrots, toucans, and commonly bees or wasps also seek tree cavities for nesting or shelter. Many Scarlet Macaw pairs also are competing for nest cavities. Therefore when a macaw pair has located an appropriate cavity, they must defend it against other animals, including other macaw pairs. This sometimes results in intense battles.
Scarlet Macaw chick development involves 22 days of eclosion (from egg laying to hatching) and about 75 days of chick development for a total of about 97 days. Up to four eggs are laid, but only 2 or rarely 3 will hatch. Eggs are laid several days apart so the first born nestling is larger then its sibling. Unfortunately the older nestling usually out-competes its younger sibling which will often starve.
The chicks hatch, featherless and helpless, with their eyes closed and remain in the nest until fledging. After leaving the nest fledglings fly with parents, learn to feed and socialize and start roosting in Guacalillo Mangrove Reserve with the rest of the flock.
The Scarlet Macaw’s main diet consists of seeds and fruits, with occasional leaves or bark. Trees produce fruit at different times throughout the year so a young macaw must learn from its parents when each type of fruit is available and is dependent on supplemental feeding from their parents until at least 3 months of age.
Macaws have very strong beaks which facilitates cracking hard seeds that other animals cannot. They also eat large quantities of fruits which are toxic to humans, like Jabillo and Espavel. In South America, macaws eat clay from riverbanks to neutralize toxins in these foods, but in Costa Rica, how they neutralize toxins in foods is still a mystery. Central Pacific Scarlet Macaws eat fruits and seeds from over 40 native tree species, but they also eat seeds of exotic species. These include beach almond (Terminalia Catappa), teak (Tectona Grandis) and Melina (Gmelina Arborea). Luckily the macaws feed on only the seeds/fruits of Teak and Melina, because these trees are grown in plantations for their wood.
Most of the Scarlet Macaws of Central Pacific Costa Rica roost in Guacalillo Mangrove Reserve near Carara National Park. They awake between 5-7 am and fly in pairs or family groups along three fly-routes to feed. The first fly route (Tarcoles) follows the beach and macaws gather in large groups near the local town, Tárcoles to feed on beach almond seeds. The second fly-route (Central) leads to or behind Carara National Park. The last fly route (Rio) follows the Rio Tárcoles to the north of Carara National Park. In both the Central and Rio fly-routes, the macaws may feed on native forest fruits in exotic Teak or Melina plantations.
Scarlet Macaws are very social and apart from feeding in groups they may also gather in flocks of 50 or more birds in large trees to play, fight, and preen themselves and their partner.
In the afternoon the macaws return to the mangrove reserve, but may stop en route to feed and socialize before arriving at the mangroves to roost.
September - December: Scarlet macaw pairs look for appropriate nest holes and guard them
December - February: Females lay eggs and incubate them for 22 days
January- February: Chicks hatch
March - April - May: Chicks fledge from nests at around 75 days old
June - August: Chicks fly with parents, learn to feed and socialize and start roosting in Guacalillo Mangrove Reserve with the rest of the flock.