South American Coati

An adult South American coati has a head-and-body length of roughly 41 to 67 cm, with a tail that adds another 32 to 69 cm. Standing about 30 cm at the shoulder and weighing between 3 and 7 kg, it is a lightly built animal for its length, because so much of that length is tail. The coat is dark brown, grey, or rust above and paler below, and the tail carries a series of rings that can be faint or clearly marked depending on the individual and the population.

The tail is not prehensile, but it is central to how coatis live. On the ground and while climbing, it works as a balancing rod. In a moving band it also works as a signal: raised vertically with its rings exposed, it is easy for other group members to follow through dense undergrowth.

The head narrows to a long, flexible snout that turns slightly upward at the tip. This snout is the animal's main foraging tool. It bends and probes into crevices, under bark, and through soil, guided by a keen sense of smell. The forelimbs are strong and end in robust, curved claws used for digging and climbing. A less obvious adaptation lies in the ankles: the joints can rotate so that the hind feet turn backward, letting a coati grip a trunk and descend headfirst rather than backing down.

The South American coati ranges widely across the continent east of the Andes, from Colombia, Venezuela, and the Guianas south through Brazil, Ecuador, Peru, Bolivia, and Paraguay to Uruguay and northern Argentina. It lives from lowland forest up to about 2,500 metres on Andean slopes.

It is not tied to a single forest type. Records span evergreen rainforest, deciduous and cloud forest, riverine gallery forest along watercourses, and drier habitats such as Chaco woodland, cerrado, and xeric scrub. Coatis often do well in secondary forest and along forest edges, including landscapes altered by people, which is part of why the species remains widespread. A population has also become established outside its native range on the island of Mallorca, where it is treated as an invasive species.

Within this range coatis are mainly terrestrial foragers but thoroughly at home in trees. They sleep, mate, and give birth in the canopy, moving up and down trunks with the reversible-ankle grip described above.

The South American coati is an omnivore, and its diet shifts with what is locally available. Fruit and invertebrates make up the bulk of it. Reported prey includes beetle larvae, ants, termites, spiders, scorpions, and centipedes, along with fruit from palms and other trees. Coatis also take eggs, lizards, small rodents and other small mammals, and carrion, and they will occasionally raid poultry near settlements.

Foraging is active and physical. A coati probes the ground and leaf litter with its snout, flips over rocks, and tears open rotting logs to reach the animals inside. The same flexibility that lets the snout work into tight spaces makes the animal an effective generalist, able to switch between fruiting trees in one season and ground invertebrates in another. Feeding usually happens as a group, with band members spread out but within sight of one another.

Coati social life is split along age and sex lines, and this is one of the most distinctive things about the species. Females and their young live together in bands that can number up to about 30 animals. These bands forage, travel, and rest together, and the raised, ringed tails help keep the group coordinated as it moves.

Adult males, by contrast, are generally solitary. They range on their own for most of the year and associate with a band mainly during the breeding season. Neither males nor bands defend strict exclusive territories; home ranges overlap. The difference in habits between grouping females and lone males was striking enough that early naturalists described the solitary males as a separate kind of animal, the "coatimundi" — a name that survives today even though it refers to the same species.

Coatis are diurnal, spending most daylight hours on the move and foraging, then retreating to trees to rest overnight. They are agile climbers and capable swimmers.

Breeding is seasonal and timed so that most births fall in a favourable period, commonly around April to June across much of the range, following mating in the preceding months. When a female is ready to give birth she leaves her band and builds a nest in a tree.

Gestation lasts about 74 to 77 days. A litter usually contains three to seven kits, with around four being typical. The kits are born in the tree nest and remain there while very young. After roughly five to six weeks the female brings her kits down and rejoins the band, and the young are then reared within the group. Females generally reach breeding age at about two years and males somewhat later, around three years.

The South American coati is Nasua nasua, a member of the family Procyonidae — the raccoon family — within the order Carnivora. Its closest well-known relative is the raccoon, and the two share the ringed tail and nimble forepaws typical of the family. The genus Nasua also contains the white-nosed coati of Central and North America; the South American species can be told apart by its lack of a broadly white snout. Numerous subspecies have been described across its wide range.

Although coatis sit within the carnivore order, their omnivorous, invertebrate-and-fruit diet is closer to that of other flexible feeders than to that of dedicated meat-eaters. Comparable ecological roles are filled elsewhere by animals such as the binturong in Southeast Asian forests, the fruit-and-bamboo-eating red panda of the Himalayas, and the group-living, insect-hunting meerkat of southern Africa, none of them close relatives but all illustrating how carnivoran lineages have taken up varied diets and social systems.

The IUCN Red List classifies the South American coati as Least Concern. The species is widespread, tolerant of a range of forest types, present in many protected areas, and able to persist in edge and secondary habitats. Its global population trend is listed as unknown, so the Least Concern rating should not be read as evidence that every local population is secure.

Where pressures concentrate, coatis can decline locally. The main threats are hunting for meat and habitat loss through deforestation and fragmentation. In heavily cleared or heavily hunted areas these factors can reduce numbers even while the species as a whole remains common. Because coatis are diurnal, conspicuous, and often live near people, they are also relatively easy to hunt, which makes local monitoring the most useful conservation measure in regions under pressure.

• IUCN Red List: Nasua nasua (South American Coati)
• Animal Diversity Web: Nasua nasua
• Wikipedia: South American coati
• AnAge / Human Ageing Genomic Resources: Nasua nasua longevity
• World Land Trust: South American coati species profile