Overview
The Sunda Long-eared Bat (Nyctophilus heran) is a rare and poorly understood vespertilionid microbat endemic to the Lesser Sunda Islands of Indonesia. Described in 1991 from specimens collected on the island of Lembata, with subsequent records on Flores and Sumba, it represents a remarkable western geographic outpost for the genus Nyctophilus, which is predominantly Australasian. Characterized by spectacular oversized ears connected across the forehead, it is a master of slow, maneuvering flight within dense forest understories.
Biology and Physical Characteristics
Nyctophilus heran possesses a soft, fluffy pelage colored sandy-brown to drab grayish-buff across its dorsum, fading to paler grayish-white on the belly. Its most conspicuous morphological hallmark is its pair of enormous, oval ears that measure over half the length of its entire body. These ribbed, membranous sound-gatherers are conjoined at their bases across the forehead by a low band of skin. Behind the nostrils sits a low, fleshy horseshoe-shaped nose-leaf. Its wings are broad and short, providing exceptional aerodynamic lift and maneuverability suited for hovering within tangled vegetation.
Behavior and Ecology
Unlike high-flying aerial insectivores that pursue prey in open airspace, the Sunda long-eared bat is an obligate foliage gleaner. It emits whisper-quiet, broad-band frequency-modulated echolocation pulses that allow it to navigate through cluttered branches without alerting acoustic-sensitive moths. Supported by its enormous acoustic ears, it can detect the faint rustling sounds generated by katydids and caterpillars walking across leaf surfaces, plucking them cleanly from foliage while hovering momentarily in mid-air. During daylight hours, it roosts in small colonies inside limestone caves, hollow tree branches, and exfoliating bark.
Conservation and Human Impact
Currently assessed as Data Deficient by the IUCN due to the scarcity of comprehensive ecological surveys across the Lesser Sunda archipelago, Nyctophilus heran is likely threatened by ongoing habitat loss. Lowland dry monsoon forests on Flores and Sumba have undergone heavy fragmentation from slash-and-burn farming, livestock grazing, and uncontrolled wild fires. Establishing dedicated cave sanctuary zones and conducting bioacoustic surveys are vital conservation priorities.
Interesting Factoid
The Sunda Long-eared Bat has ears so gigantic that they make up more than half the length of its entire body, allowing it to hear the footsteps of a tiny caterpillar walking on a leaf in pitch-black darkness!
Last updated: October 2026