Ara glaucogularis
blue-throated macaw

Blue-throated macaws (Ara glaucogularis) are found only in the Beni department of Bolivia (200 to 300 m above sea-level). In total, blue-throated macaws inhabit an area of 2508 square kilometres. (Hesse and Duffield, 2000; "Blue-throated Macaw", 2009)

There are two areas inhabited by two sub-populations of Ara glaucogularis: one is to the northwest of Trinidad (the capital city of Beni), and the other is to the south of Trinidad. This separation may have occurred because of the indigenous peoples that historically inhabited this area and hunted blue-throated macaws to use the feathers in ornamental costume. This separation could also have been caused more recently by the wild-bird trade. With the high population of humans, any blue-throated macaws in the vicinity would have a higher chance of being caught. The formation of large human settlements in this area also resulted in a loss of suitable habitat and habitat fragmentation for this species. Hence, there are no blue-throated macaws in the vicinity of Trinidad. (Hesse and Duffield, 2000; Strem, 2008)

Blue-throated macaws inhabit gallery forests and islands of trees surrounded by a tropical savanna. Seasonal rains cause flooding from October to May and transform the savanna into a grassy swamp surrounding permanently dry elevated forest islands. The presence of Motacú palms (Attalea phalerata) is required for the survival of Ara glaucogularis as this species of macaw feeds and nests in these palms more than any other species of plant. They occur most often between the elevations of 200 and 300 m. (Benstead, et al., 2009; Hesse and Duffield, 2000; Jordan and Munn, 1993)

Most of blue-throated macaws' habitat is used for cattle ranching. However, the land is unsuitable for cultivation, so habitat alteration for agricultural use does not occur. Although cattle will trample saplings, mature Motacú palms are very hardy and resist damage. This palm is somewhat fire resistant as well. As a result, Motacú palms often dominate the forest fragments in the Beni Savanna. (Hesse and Duffield, 2000)

Blue-throated macaws have very vivid coloration. They have bright turquoise-blue feathers covering their throat, crown, back and the dorsal side of their wings and tail. Golden-yellow feathers grow in a stripe between the blue crown and throat on the side of the face and on the ventral side of their body, wings and tail. On the face there is a sparsely feathered patch of skin near the base of the large dark-colored bill that has 5 or 6 horizontal stripes of blue feathers which are unique for every blue-throated macaw and can be used to individually identify adults. The skin on this patch is predominantly white with a pink tint close to the bill. (Benstead, et al., 2009; Kyle, 2007a)

Adult blue-throated macaws' mass ranges from 600 to 1000 g with a length of about 85 cm (measured from the top of the head to tip of the long, tapered tail) and a wingspan of approximately three feet or 0.9 m. Ara glaucogularis shows little easily observable sexual dimorphism; however, males tend to be a little bigger than females with approximate masses of 600 g and 800 g respectively. (Benstead, et al., 2009; Clubb, 1994; Clubb, 2009; Kyle, 2007a)

Newly hatched blue-throated macaws are completely pink and have no feathers. Gray down grows in as they age, and is later replaced by colored, fully-developed feathers. The iris also changes color with age. The eye color of a nestling is initially black and changes to brown soon after the eyes open. When the macaaw is one to three years old, its eyes will turn grey, then white. As the macaw matures, the iris turns yellow and will be more golden at 10 years and will become a richer gold with age. Elderly macaws show a ring of dark grey surrounding the pupil where the iris has become thinner and the back of the retina shows through. This continuum of the iris’ colour can be used to estimate the age of a macaw. (Clubb, 1994; Clubb, 2009; Kyle, 2007b)

Blue-throated macaws look very similar to the more common blue and gold macaws (Ara ararauna). However, they can be distinguished most clearly by the colors of the feathers on the throat and crown. Blue-throated macaws have 5 or 6 horizontal lines of feathers across the otherwise bare facial patch while blue and gold macaws have 3. Blue-throated macaws are smaller and also have a more nasal, higher-pitched and softer voice in comparison to blue and gold macaws. (Benstead, et al., 2009; Kyle, 2007a; Riviere, et al., 1986; "Blue and Gold Macaw", 2009)

Polymorphisms, seasonal and geographical variations have not been observed in blue-throated macaws.

Blue-throated macaws are monogamous and mate for life. It is not known if these macaws will pair with another mate if their original mate dies. Nothing else is known about mating systems for Ara glaucogularis in the wild. (Kyle, 2007b)

Blue-throated macaws breed once a year if the environmental conditions permit them; however, if the eggs or nestlings are lost, the breeding pair may produce a second clutch in the same breeding season. It has been speculated that the two sub-populations breed at slightly different times: the northern population breed from August to November and the southern population breed from November to March. The female will lay one to three eggs per clutch and incubates for 26 days. Blue-throated macaws have a mass of approximately 18 g at hatching. The nestlings fledge at 13 to 14 weeks. Young blue-throated macaws will not be fully independent of their parents for a full year. Blue-throated macaws will be sexually mature at about 5 years. (Benstead, et al., 2009; Clubb, 1994; Kyle, 2007b; Kyle, 2007a; Strem, 2008; "Blue-throated Macaw", 2009)

Ara glaucogularis usually nests in cavities of palm trees, most often Attalea phalerata, although it will nest in other palm species as well. Dead palms are ideal to nest in as they are hollowed out by large grubs after the tree has died. Some macaw species, including Ara glaucogularis, will eat the palm fronds to an extent that will kill the tree. The trunk of the palm is hollowed out by grubs resulting in the creation of a potential nest. It is not yet known whether this is coincidence or if these birds do this intentionally to create nest sites. (Gilardi, et al., 2005; Hesse and Duffield, 2000; Jordan and Munn, 1993; Kyle, 2007b; Strem, 2008)

Nesting pairs of Ara glaucogularis don’t consistently stay at one nest for consecutive breeding seasons and will usually search for different nesting sites every year. (Kyle, 2007b)

A mating pair of Blue-throated macaws must find a suitable nest before fertilization occurs. If a nest site cannot be found, the pair may excavate their own nest. While deciduous trees can be used, dead palms are easier to hollow out and are used quite often. Prospective parents must also withstand competition for nest sites from other macaw species such as Ara ararauna, Ara chloroptera and Ara macao as well as toco toucans, large woodpeckers, barn owls, bats, and bees. (Benstead, et al., 2009; Kyle, 2007b; Kyle, 2007a)

Female blue-throated macaws lay the eggs and incubate them until they hatch. Males feed the females during incubation. Both parents feed the nestlings once the chicks have hatched and the precocial chicks must be kept warm by their parents before their feathers grow in. After the nestlings’ feathers grow in they are often left alone while both parents gather food. The young macaws are still dependent upon their parents for food after they fledge until they are fully weaned and capable of foraging by themselves. Even after the juvenile macaws are able to provide for themselves, it has been observed that young blue-throated macaws will stay with their parents up to a year. During this time, the parents will skip an entire breeding season. (Kyle, 2007b; Kyle, 2007a)

In captivity, blue-throated macaws are able to breed up to about 30 to 35 years, after which aging and age related diseases begin to show. Very few macaws in captivity live to 50 years of age. Blue-throated macaws have not been studied very long in the wild, and information on lifespan is yet to be discovered. (Clubb and Karpinski, 1992; Clubb, 1994)

Blue-throated macaws are social birds as they form monogamous mating pairs and will also live in small groups. One group of 70 individuals was known at one point, but this species is not often seen in large flocks as other species of macaws have. This is most likely because blue-throated macaws are very rare and have such a low population that the formation of such large groups is very unlikely. A mating pair of blue-throated macaws can be very affectionate towards one another and are often seen preening each other's feathers and perching close together. Blue-throated macaws are sometimes seen interacting with blue and gold macaws (Ara ararauna) as well. (Benstead, et al., 2009; Kyle, 2007b; Benstead, et al., 1992)

Blue-throated macaws live, feed and nest in trees. Their main mode of locomotion is flying, but they are also able to climb trees, maneuver along branches and walk on the ground. These birds are active during the day and usually stay in one general area. There have been sightings of blue-throated macaws in Paraguay, which indicates that this species will sometimes travel long distances. (Kyle, 2007b; Benstead, et al., 1992)

There is not very much information available pertaining to the home ranges of individual blue-throated macaws or pairs.

Blue-throated macaws communicate mostly by sound. When they suspect danger, they emit a very loud alarming call and promptly fly off. Blue-throated macaws are known to communicate with each other with quiet caws as well. Toa Kyle (2007b) describes his observations of the “almost fledging” of a blue-throated macaw chick during which the chick received “light caws of encouragement from its parents perched nearby.” Bird trappers have been known to use “caller” bait birds to attract blue-throated macaws of the opposite sex, so acoustic communication is known to have a role for attracting mates. Tactile communication is used as well. Mates show affection for each other and their chicks quite often in the form of preening. Like all birds, blue-throated macaws perceive their environment through audio, visual, tactile, and chemical stimuli. (Kyle, 2007b; Kyle, 2007a; Benstead, et al., 1992)

Blue-throated macaws do not eat seeds and nuts to the same extent as many other macaw species do. Instead, they eat primarily fruit from large palms. The palm species Attalea phalerata is the most predominant source, but they will also eat from Acrocomia aculeata and Mauritia fleuxosa. The macaws eat the mesocarp from ripe and nearly ripe fruit and have also been observed drinking the liquid from very immature fruit. (Benstead, et al., 2009; Jordan and Munn, 1993; Kyle, 2007b; Strem, 2008)

Blue-throated macaws’ cautiousness is one of their behavioral adaptations to prevent nest predation. Parents will often perch just outside their nest and observe their surroundings for predators and other dangers. When returning from foraging, blue-throated macaws will approach the nest tree gradually only after observing the area first. While one parent enters the nest to feed the chicks, the other parent has been observed to stand guard near the nest tree. (Kyle, 2007a; Pederson and Pederson, 2002)

Few predators of Ara glaucogularis exist. Adults can be preyed upon by great horned owls, southern caracaras, coati, tayras, and brown capuchin monkeys. Nestlings are preyed upon by crane hawks, while both eggs and nestlings are eaten by toco toucans. (Gilardi, et al., 2005; Kyle, 2007b)

Blue-throated macaws play a role as prey in their ecosystem. They are also subject to parasites such as mites and botfly larvae. As frugivores, they are likely an important seed disperser for native, fruiting plants. (Kyle, 2007b)

Blue-throated macaws are used as pets. Their feathers have also been used for decoration of ornamental costume for indigenous groups. (Hesse and Duffield, 2000; Strem, 2008)

There are no known adverse effects of Ara glaucogularis on humans.

Ara glaucogularis is currently rated as critically endangered on the IUCN Red List and is listed in Appendix I by CITES. Trapping is illegal as blue-throated macaws have been protected by the national legislation of Bolivia and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1986. (Strem, 2008; "Blue-throated Macaw", 2009)

Trapping for the pet trade is the main reason that blue-fronted macaws are so critically endangered. The rarity of this species drove the selling price up resulting in increased pressure from trapping. As more birds were caught, blue-throated macaws became rarer. This became a vicious cycle that greatly reduced the wild population of blue-throated macaws to the numbers presently observed. There are currently an estimated 50 to 250 individuals in the wild. (Hesse and Duffield, 2000; Jordan and Munn, 1993; "Blue-throated Macaw", 2009)

Since spix's macaws (Cyanopsitta spixii) went extinct in 2000, Ara glaucogularis is now the most rare species of macaw in the world. With a wild population estimated to be between 50 and 250 individuals, extreme conservation actions are necessary. The World Parrot Trust has many volunteers and employees working towards the conservation of blue-throated macaws. These people monitor the nests to protect the chicks from predation. Chicks are also examined periodically to ensure that they are healthy and receiving adequate food from their parents. If the chick is not doing as well as is expected, then it is supplemented with formula. New nest boxes have been built and current nest sites improved. Support from the local landowners has also been established. (Gilardi, et al., 2005; Kyle, 2006; Kyle, 2007b; Kyle, 2007a)