Tarsiers: Tarsiidae

Physical characteristics: The western tarsier is yellowish beige or sand-colored. Enormous, goggled eyes take up most of its face. The eyes cannot move within the sockets, so a flexible neck turns the head around almost 180° for a backward look. Large ears are in constant motion as they follow the sounds of possible prey. The fingers and toes are very long and have suction pads at the tips for gripping tree branches. Fingernails and toenails are flattened, except for those on the second and third toes. These two toes have grooming claws, used for cleaning the fur of dead skin and parasites and for scratching. The long, rod-like tail is bare with a small clump of hair at the end. Ridges on the inside part of the tail support the tarsier when it clings to tree trunks or branches.

Geographic range: Western tarsiers are found in Indonesia.

Habitat: Western tarsiers favor secondary forests, with their dense ground vegetation and small trees. They also inhabit primary forests, characterized by a full-ceiling canopy and trees of different heights. They are found in human settlements and plantations.

Diet: Western tarsiers eat primarily large insects, including beetles, cockroaches, praying mantis, cicadas, butterflies, and grasshoppers. They also feed on birds, bats, and snakes. They even eat poisonous snakes.

Behavior and reproduction: The western tarsier forages for food alone at night and at dawn and dusk, listening for sounds made by insects on the ground and catching them with its hands. It closes its eyes when attacking insects to protect its eyes. During the day, males and females sleep separately, either among vines and tangled vegetation or while clinging to vertical tree trunks or branches. Using urine and scent gland secretions, tarsiers scent mark tree branches to advertise territory ownership. They are rather quiet, although females vocalize when ready to mate.

Western tarsiers may be monogamous (muh-NAH-guh-mus), having just one partner, or polygynous (puh-LIH-juh-nus), with males having several partners. Births occur throughout the year, although more births occur between February and June at the end of the rainy season. Females give birth to a single infant that weighs about one quarter of its mother's weight. The well-developed infant is born with a full coat and open eyes. It can climb right away after birth.

Western tarsiers and people: The Ibans, the indigenous people of Sarawak, Borneo, who were once head-hunters, considered the western tarsier as an omen animal. They had seen the tarsier rotate its head full circle and thought the tarsier had a loose head. A headhunter who encountered a tarsier would turn around right away so as not to incur the spirits' spell on him and his people. Today, tarsiers are taken for pets but do not survive in captivity.

Conservation status: The IUCN lists the western tarsier as Data Deficient, a category that does not refer to a threatened species. This means that the species may be well-studied, but there is not enough information about its population status. ∎