LORISES AND POTTOS: Lorisidae

PHYSICAL CHARACTERISTICS

Lorises and pottos have short heads covered with hair. Snouts, or nose areas, are small. Their C-shaped ears are close to the scalp, and they have large, round, dark eyes. Arms and legs are long and about equal length. All ten fingers and ten toes have a claw, but the claw is longest on the second toe. This is called a grooming claw, and lorises and pottos use it to comb through and clean their fur. The index finger is quite small compared to the rest of the fingers, and their thumbs and big toes are located far from the other four fingers and toes. When these animals wrap their hands or feet around a tree branch, their grasping hold is very strong, allowing them to hold onto a branch for a long time.

Lorises and pottos are very small animals. The tiniest loris is the gray slender loris. It is only 8.5 inches (21.5 centimeters) long from head to the start of its tail. It weighs only 9 ounces (255 grams). The potto is the largest member of the Lorisidae. Tail length varies in the lorises and the pottos. Some, such as the slender loris, have no tail. Others may have a tail length of up to 2.5 inches (6.5 cm). Their color varies; pottos and lorises can be cream colored, pale brown, grayish brown, reddish brown, orange-brown, or dark brown. Some have mixed fur colors. Some lorises have contrasting markings or striped areas. The color contrast may be especially visible when it forms a ringed area around the large eyes, as it does in the pygmy slow loris.

GEOGRAPHIC RANGE

The slow lorises live throughout tropical rainforests in Southeast Asia. The slender lorises are found in the tropical forests of India and Sri Lanka. Pottos occur only in the tropical and subtropical forests of West and Central Africa.

HABITAT

Lorises and pottos live only in thickly forested areas. Most often, they live in the trees of tropical rainforests, forests where the trees are evergreen and there is a lot of rain.

DIET

Lorises are omnivores, eating both plants and very small animals. They are nocturnal, feeding at night. They locate food with their keen sense of smell. Diet includes insects, lizards, fruits, leaves, birds' eggs, and gum, the liquid from plants. Each species, or type, of Lorisidae, may have a food preference. When feeding, they hang by their feet from a branch.

BEHAVIOR AND REPRODUCTION

Lorisids (species in the family Lorisidae) are usually solitary animals, each having a specific range for its food searches. However, the home range (place where an animal feeds and lives) of males may overlap that of females. During the day, lorisids may sleep on a tree branch, in a hollow tree trunk, or in the fork of a tree. They typically sleep while curled up, with head and arms tucked between their thighs. While they see well in daylight and dark, they search for food at night. The animals move very slowly and carefully. Sometimes they don't even disturb tree leaves as they pass through. This careful behavior helps them to avoid predators, animals that hunt them for food. While moving through tree branches, they tend to drag their bottoms to mark their trail with urine. If a lorisid hears even the slightest sound that might mean a predator is nearby, it just stops and hangs on to a branch. With strong arms and legs, it can stay that way for hours, until it feels it can safely move again.

LORISID COMMUNICATION

When Asian lorisids want to communicate with each other, they make specific noises, or vocalizations. Sounds vary by species, and include panting, hissing, growling, soft and loud whistles, rapid clicking, and chirping. The clicking sound made by infants when separated from their mother is a series of short, sharp, rapid clicks called a "zic" call.

Lorisids may have more than one mate. Pregnancy is from about four to six months, depending on the species. Lorisids usually have just one baby at a time. Babies weigh from 1 to 2 ounces (28.4 to 56.7 grams). After a baby is born, it hangs on to the front fur of its mother's body for a few weeks. Sometimes, as she searches for food at night, the mother may place her infant on a small branch. The infant holds onto the branch until the mother returns. At night, while the mother sleeps, the baby holds onto her belly. As the infant grows, it begins to travel on its mother's back. Then it follows her. As the mother looks for food, she also is teaching her young how to look for, and recognize, suitable food. Young lorisids stay with their mother until they are about a year old, then go off on their own.

LORISES, POTTOS, AND PEOPLE

Large zoos may have special exhibits of lorisids and pottos. In their native homes, in some areas, they are trapped and kept as pets. Occasionally the larger species are used as food.

POTTOS DEFEAT AN ENEMY

If a potto senses a predator, or enemy, it holds onto a branch and stays very still. Because its arms and legs are so strong, it can stay in this non-moving position for several hours, until the predator gives up and goes away.

If it must fight, the potto first turns its thickened neck hump, or shield, toward the attacker, while keeping its hands and feet tightly clamped on a branch. It then makes a series of sideways movements. It tries to hit the enemy with its hump. If the potto is successful, the enemy falls to the ground below.

CONSERVATION STATUS

While no Lorisidae are considered Endangered, two are Vulnerable (facing a high risk of extinction, or dying out, in the wild) due to habitat loss. Two are Near Threatened (not currently threatened with extinction), and four species are fairly common.

PYGMY SLOW LORIS (Nycticebus pygmaeus): SPECIES ACCOUNTS

Physical characteristics: This small loris is only 10 inches long (25.5 cm). It has no tail. Weight is just 11 ounces (310 grams), with males and females about the same size. The pygmy loris is colorful. It has bright orange-brown fur on its upper back and a light orange-gray area on its upper chest. Its face is gray, with a dark orange-brown eye mask, and a white stripe between its eyes.

Geographic range: The pygmy slow loris is found in China, Laos, and Vietnam.

Habitat: Pygmy slow lorises thrive in evergreen tropical rainforests.

Diet: Pygmy slow lorises eat fruit, insects, and gums (plant juices). Some scientists believe this species prefers to eat gum, because in captivity they have been seen making holes in tree wood to get plant sap.

Behavior and reproduction: Pygmy slow lorises usually travel and feed alone. Each has a preferred territory where it lives. During the day, the pygmy slow loris sleeps holding on to branches in the midst of thick leaves and branches. At night, they use their strong arms and legs to move slowly and carefully, hand-over-hand, through trees. Like other lorisids, they mark their trails with urine.

Their mating system is not currently known. Females are pregnant for 192 days, a little more than six months. They may have one offspring (baby), or twins. Babies stay with the mother for a few weeks, hanging on to her belly. As the infant grows, it clings to its mother's back while she travels. Then it follows her. Young pygmy lorises stay with their mother until they are about a year old, then go off on their own.

Pygmy slow lorises and people: Because they move around mostly at night, and are quite small, few people see them. However, some pygmy slow lorises are kept as pets in their native areas. Large zoos may include them in special exhibits.

Conservation status: The pygmy slow loris is listed as Vulnerable due to habitat loss from deforestation. ∎

POTTO (Perodicticus potto): SPECIES ACCOUNTS

Physical characteristics: Pottos have dark fur on the top of theirbody, and light brown fur underneath. They have a body length of 15 inches (38.1 centimeters) with a 2.5-inch tail (6.5 centimeters). A grown potto weighs only about 2.75 pounds (1.25 kilograms). Its dark eyes are large and round.

As protection from predators, a potto's upper back has a humped area of thickened skin on top of long vertebral spines. This thickened area, often called a shield, is covered by fur and contains long tactile, or feeler, hairs. These tactile hairs help detect a possible predator attack, and the shield can be turned toward the predator to help protect the potto from the attack.

Geographic range: Pottos are found in Africa, including Nigeria, Sierra Leone, Ghana, Cameroon, Equatorial Guinea, Gabon, Congo, Democratic Republic of the Congo, Uganda, and Kenya.

Diet: Pottos eat mostly fruit, but they also eat insects and gums (plant juices). They find insects by smell. They will eat insects that other animals might avoid, such as ants, hairy caterpillars, slugs, and stinky beetles.

Behavior and reproduction: Pottos usually live alone. They move about at night in the trees, traveling quite slowly hand over hand. They mark their trails with urine. During the day, pottos sleep in thickly leaved branches.

Female pottos usually have one infant after being pregnant for about 163 days. A potto baby weighs just 2 ounces (56.7 grams). It has a thin layer of fine fur. It eyes are open. From the first day, the infant holds on to the mother's front and travels with her until it becomes more independent. It will leave its mother at about one year old.

Pottos and people: Potto habits of moving slowly and carefully at night, high in the trees, make them difficult to study.

Conservation status: Pottos are listed as Vulnerable. The major problem is habitat, or living site, destruction due to deforestation, cutting down trees. ∎

FOR MORE INFORMATION

Books:

Alterman, Lon, Gerald A. Doyle, and M. Kay Izard, eds. Creatures of the Dark: The Nocturnal Prosimians. New York: Kluwer Academic Publishers, 1995.

Ankel-Simons, Friderun. Primate Anatomy: An Introduction. San Diego, CA: Academic Press, 1999.

Konstant, William R., and Ronald M. Nowak. Walker's Primates of the World. Baltimore: Johns Hopkins University Press, 2000.

Martin, Patricia A. Fink. Lemurs, Lorises, and Other Lower Primates. Danbury, CT: Children's Press, 2000.

Nowak, Ronald M. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press, 1999.

Nowak, Ronald M. "Lorises, Potto, and Galagos." In Walker's Mammals of the World Online. Baltimore: Johns Hopkins University Press, 1997. http://www.press.jhu.edu/books/walkers_mammals_of_the_world/primates/primates.lorisidae.html (accessed on July 5, 2004).

Rowe, Noel. The Pictorial Guide to the Living Primates. East Hampton, NY: Pogonias Press, 1996.

Periodicals:

Churchman, Deborah. "Meet the Primates!" Ranger Rick 31, no. 10 (October 1997): 8.

Stewart, Doug. "Prosimians Find a Home Far From Home." National Wildlife (Feb/Mar 1998): 33–35.

"Super Slow, Super Fast." Ranger Rick (August 1995): 3.

"Wildlife of Tropical Rain Forests." National Geographic World (January 2000): 22–25.

Web sites:

"Loridae." Wisconsin Regional Primate Research Center. http://www.primates.com/primate/loridae.html (accessed on July 5, 2004).

Schulze, Helga. "Loris and Potto Conservation Database." Loris Conservation Project. http://www.loris-conservation.org/database/info.html (accessed on July 5, 2004).

Schulze, Helga. "Acoustic Communication in Northern Ceylonese Slender Lorises and Some Information about Vocalization by Other Forms or Species of Lorisidae." Loris Conservation Project. http://www.loris-conservation.org/database/vocalization/Loris_voices_with_figures.html (accessed on July 5, 2004).