The saola (Pseudoryx nghetinhensis) is a Critically Endangered mammal so elusive it is often referred to as the “Asian Unicorn.” Discovered only in 1992, this species remains one of the world’s greatest wildlife mysteries. Scientists have never observed a saola feeding naturally in the wild, meaning information about its diet is gathered through indirect methods. Limited knowledge establishes the saola as a specialized herbivore tied to the unique flora of its remote home.
The Saola’s Restricted Geographic Range
The saola is found exclusively within the Annamite Mountains, a rugged chain running along the border between Vietnam and Laos. It inhabits the dense, wet evergreen forests that characterize the mid-to-high elevations of the Annamites. The elevation range where saolas have been documented extends from approximately 400 to 1,400 meters above sea level, though most confirmed sightings cluster around 600 to 1,100 meters. These mountain forests lack a pronounced dry season, which supports a lush, dense understory layer.
Specific Plant Consumption
The saola is classified as a folivore and a browser, meaning it primarily consumes leaves and other soft vegetation rather than grazing on grasses. Its dentition, featuring relatively short incisors, is adapted for this specialized browsing behavior. Evidence suggests the saola is a highly selective feeder, choosing soft, easily digestible leaves from specific plants.
Specific food items identified from local knowledge and the observation of a brief captive individual include leaves from fig trees and various riverside bushes. The saola appears to favor an aromatic herb known as Homalomena aromatica, which is native to the region. Other plants linked to the diet include ferns (Asplenium species) and broad-leaved species from the Sterculiaceae family.
Observations of a captive saola indicated a delicate feeding style. The animal chewed the petiole to detach the leaf rather than pulling or jerking the entire plant. The saola’s preference for riparian vegetation suggests it forages along forested streams, where plant life is particularly lush.
Challenges in Observing Saola Feeding Habits
Studying the saola’s diet is exceptionally difficult because no biologist has yet seen one feeding in the wild. The species’ extreme shyness and preference for remote, steep terrain make direct observation practically impossible. Scientists must rely on indirect evidence, such as analyzing fecal samples to identify plant fragments or using camera traps.
Fecal analysis, which can involve DNA metabarcoding, provides the most objective data on the saola’s food intake. However, collecting fresh saola dung is rare due to the animal’s scarcity and vast home range. Historically, attempts to study captive saolas have been unsuccessful, as all captured individuals perished shortly after, likely due to stress and lack of proper nutrition.
Conservationists are now working with local communities to cultivate plants known to be favored by the saola, such as Homalomena aromatica. This effort aims to ensure food availability and aid in future monitoring. The limited, fragmented data sources mean that much about the saola’s seasonal dietary shifts and foraging patterns remains unknown.