Adult coatis measure 33 to 69 cm (13 to 27 inches) from head to the base of the tail, which can be as long as their bodies. Coatis are about 30 cm (12 inches) tall at the shoulder, and weigh between 3 and 8 kg (between 6 and 18 pounds), about the size of a large housecat. Males can become almost twice as large as females and have large, sharp canine teeth.
All coatis share a slender head with an elongated, flexible, slightly upward-turned nose, small ears, dark feet and a long, non-prehensile tail used for balance and signaling.
Ring-Tailed coatis have either a light brown or black coat, with a lighter under-part and a white-ringed tail in most cases. Coatis have a long brown tail with rings on it which are anywhere from starkly defined like a raccoon's to very faint. Like the raccoons and unlike ringtails and cacomistles, the rings go completely around the tail. Coatis often hold the tail erect, and it used as such to keep troops of coatis together in tall vegetation. The tip of the tail can be moved a bit on its own, as is the case with cats, but it is not prehensile as is that of the kinkajou, another procyonid. Coatis are known for dipping their nose into substances with certain smells like soap, perfume, et cetera and then rubbing it into their tail. It is not known if this is more or less common in the wild. The tail position may also signal mood and willingness to be approached by other coatis.
The coati has bear- and raccoon-like paws, and coatis, raccoons, and bears walk plantigrade (on the soles of the feet, as do people). Coatis have non-retractable claws. Coatis also have in common with raccoons and other procyonids (and others in the order Carnivora and rare cases amongst other mammals) double-jointed and ankles rotatable beyond 180° and therefore the ability to descend trees head-first. Other animals living in forests have acquired some or all of these properties through convergent evolution, including members of the mongoose, civet, ferret-skunk, cat, and bear families. Some of these animals walk on the toes of the front paws and soles of the back paws.
The coati snout is long and somewhat pig-like and extremely flexible and can be rotated up to 60 degrees in any direction, the former being part of the reason for its nickname the hog-nosed raccoon. The nose is utilized to push objects and rub parts of their body.
The facial markings include white markings around the eyes and on the ears and snout.
Coatis have strong limbs to climb and dig, and have a reputation for intelligence, like their fellow procyonid the raccoon.
They prefer to sleep or rest in elevated places and niches, like the rain forest canopy, in crudely-built sleeping nests.
The coati is a widespread species living in habitats ranging from hot and arid areas to humid Amazonian rainforests or even cold Andean mountain slopes, including grasslands and bushy areas. Their geographical range extends from southern Arizona in the USA through northern Argentina, and they are often seen in Costa Rica. The following species have been scientifically described:
The coati species cited above have different geographical occurrences and can be told apart by their size, build, voice, and their hide colour.
Genetic studies have shown that the closest relatives of the coatis are the olingos.
In the wild, coatis live for about 7 to 8 years, while in captivity they can live for up to 15 years.
The coati is an omnivore; its diet consists mainly of ground litter invertebrates and fruit (Alves-Costa et al. 2004, 2007, Hirsch 2007). They also eat small vertebrate prey, such as lizards, rodents, small birds, and bird's eggs. The snout, with a formidable sense of smell, assists the skilled paws in a hog-like manner to unearth invertebrates.
Unlike most members of the raccoon family (Procyonidae), coatis are primarily diurnal. Coati females and young males up to 2 years of age are gregarious and travel through their territories in noisy, loosely-organized bands made up of 4 to 25 individuals, foraging with their offspring on the ground or in the forest's canopy. Males over 2 years become solitary due to behavioural disposition and collective aggression from the females, and will join the female groups only during the breeding season.
When provoked, or for defense, coatis can be fierce fighters: their strong jaws, sharp canine teeth, and fast scratching paws, along with a tough hide sturdily attached to the underlying muscles, make it very difficult for predators (e.g. dogs, jaguars) to seize the small mammal.
The coati communicates its intentions or moods with chirping, snorting or grunting sounds. Different chirping sounds are used to express joy during social grooming, appeasement after fights, or to convey irritation or anger. Snorting while digging, along with an erect tail, states territorial or food claims during foraging.
Coatis additionally use special postures or moves to convey simple messages; for example, hiding the nose between the front paws as a sign for submission; lowering the head, baring teeth and jumping at an enemy signal an aggressive disposition.
Individuals recognize other coatis by their looks, voices and smells, the individual smell is intensified by special musk-glands on their necks and bellies.
Coatis from Panama are known to rub their own fur and that of other troop members with resin from Trattinnickia aspera trees. The purpose of this fur rubbing is unclear. Some possibilities that have been proposed are that it serves as an insect repellent, a fungicide or as a form of scent-marking.
The coati's breeding season mainly corresponds with the start of the rainy season to coincide with maximum availability of food, especially fruits: between January and March in some areas, and between October and February in others. During the breeding season, an adult male is accepted into the band of females and juveniles near the beginning of the breeding season, leading to a polygynous mating system.
The pregnant females separate from the group, build a nest on a tree or in a rocky niche and, after a gestation period of about 11 weeks, give birth to litters of 3 to 7 young. About six weeks after birth, the females and their young will rejoin the band. Females become sexually mature at 2 years of age, while males will acquire sexual maturity at 3 years of age.
The coati faces unregulated hunting and the serious threat of environmental destruction in Central and South America. The absence of scientifically sound population studies of Nasua or Nasuella in the wild is probably leading to a severe underestimation of the ecological problems and decline in numbers affecting the species in Central and South America.
Successful adaptation to life in human proximity (e.g. similar to raccoons living in metropolitan areas in the U.S.) is very unlikely; the species is thus threatened by habitat destruction.
The coati is a small creature that can be wild, somewhat difficult to control or train in some cases, and generally behaves radically different from a pet dog. Optimally they should have a spacious outdoor enclosure and a coati-proofed room in the house and/or other climate-controlled place as well. They can be given the run of the house but need careful watching, more careful in some cases than others.
It is possible to litter or toilet-train coatis; if one cannot be trained as such it is still possible to lessen problems in that they tend to designate a latrine area which can have a litter pan place in/under it as is done with many ferrets, pet skunks, rabbits, and rodents.
Coatis generally need both dog and cat vaccines for distemper and many other diseases and a killed rabies vaccine. They can be spayed or neutered for the same reason as cats and dogs and other pets.