How many butterfly species are found in Taiwan?

Taiwan records approximately 400 species of day-flying Rhopalocera — an exceptionally high number for an island of 36,000 km². The density of butterfly diversity per unit area is among the highest in the world at this latitude, comparable to the most productive continental Asian sites. This richness reflects Taiwan's position at the junction of Palearctic and Oriental faunal zones, its dramatic altitudinal gradient (sea level to 3,952 m), and its long isolation from mainland China — sufficient for speciation to produce numerous endemics, yet recent enough that most species retain close affinities with continental relatives. Approximately 57 species are endemic to Taiwan, including several spectacular swallowtails.

What is the most famous endemic butterfly of Taiwan?

The most celebrated Taiwanese endemic is Papilio maraho (the Maraho swallowtail or Broadtail swallowtail), classified as a 'natural monument' under Taiwanese law and featured on postage stamps and environmental campaigns. It is a large, dramatic swallowtail — dark wings with cream-yellow markings and a distinctive broad hindwing tail — restricted to montane mixed forest in the central and southern Central Mountain Range at elevations of 500–2,500 m. Its larval host plant is Sassafras randaiense, an endemic Taiwanese tree. Population size is estimated at only a few thousand individuals and it is fully protected; photography and observation are welcomed but collection is prohibited.

When is the best time to see butterflies in Taiwan?

Taiwan's long subtropical season means butterflies are present year-round in the south and at lower elevations. The peak season for overall species richness is April to June in the lowlands and May to August in the mountains. The island is also famous for spectacular butterfly migrations: hundreds of thousands of Parantica swallowtails (milkweed glassywings) migrate through the mountain passes in October–November, and large Pieridae migrations — mostly emigrants (Catopsilia) and jezebels (Delias) — cross lowland Taiwan in late autumn. The 'Purple Butterfly Valley' in Maolin, Kaohsiung, where overwintering Euploea (crow butterflies) congregate in the hundreds of thousands from November to March, is one of the world's most dramatic butterfly spectacles.

Butterfly Atlas

Butterflies of Taiwan

~2 min

Taiwan records around 400 butterfly species on an island barely 400 km long. Steep mountains compress East Asian habitats and support many endemics.

Overview

Taiwan is a high island in the western Pacific, separated from the Chinese mainland by the 180 km Taiwan Strait. Its Central Mountain Range runs the length of the island like a spine, with 268 peaks above 3,000 m and the summit of Jade Mountain (Yushan) reaching 3,952 m — the highest point in northeast Asia outside the Himalayas.

This vertical relief compresses tropical lowland forest in the south, subtropical and warm-temperate forest at middle elevations, cool-temperate forest above 2,000 m, and subalpine scrub and alpine meadow above 3,000 m into a narrow band that can be crossed in an hour's drive. The result is one of the highest butterfly diversities per unit area of any island in the world: approximately 400 species, including 57 endemic species and hundreds of endemic subspecies.

Endemics and special species

Swallowtails — Taiwan's crown jewels

Taiwan has 35 swallowtail species, of which several are strict endemics:

Papilio maraho (Maraho swallowtail) — montane forest, protected as a natural monument; larvae on Sassafras randaiense
Graphium chironides — local cliff-face and rocky gorge swallowtail of the south
Troides aeacus kaguya — the Taiwanese subspecies of the Golden birdwing, with exceptionally large females; fully protected
Byasa impediens febanus — a crimson-patched windmill restricted to Taiwan

Blues and hairstreaks — high endemism

The Lycaenidae of Taiwan include numerous narrow-range endemics, particularly in the high-mountain zone above 2,000 m:

Shijimia moorei and related high-mountain blues restricted to the Central Mountain Range
Chrysozephyrus hairstreaks — a diverse complex of oak-associated hairstreaks, many endemic to Taiwan
Arhopala species — multiple forest blues in lowland and submontane forest

Key regions and sites

Maolin — Purple Butterfly Valley

The Maolin district in Kaohsiung, in the warm southern lowlands, hosts Taiwan's most famous butterfly spectacle. From November to March, hundreds of thousands of Euploea crow butterflies (principally Euploea core and E. mulciber) overwinter in the sheltered valleys, clustering on vegetation in aggregations of tens of thousands. This "Purple Butterfly Valley" is one of only two known large butterfly overwintering sites in the world (the other being the Monarch wintering grounds in Michoacán, Mexico) and is a major eco-tourism destination. Maolin also holds excellent lowland forest butterflies year-round.

Taroko Gorge — Hualien

The dramatic marble gorge of Taroko National Park on the eastern coast offers outstanding butterfly watching at multiple elevations. The gorge road passes from subtropical forest at sea level through montane forest to the ridge at 3,000 m. Lycaenidae diversity is particularly high; several endemic hairstreaks are most reliably found here. The exposed rock faces and river beaches provide mud-puddling sites for swallowtails, Charaxes relatives, and Pieridae.

Alishan — Central Mountain forests

The Alishan mountain area (1,400–2,700 m), accessible by the famous narrow-gauge railway from Chiayi, is the classic site for Taiwanese montane butterflies. Cool-temperate forest with Chamaecyparis cypress, oak, and Sassafras supports endemics including Papilio maraho and numerous endemic hairstreaks. April to June is the peak season at this elevation.

Kenting National Park — southern tip

The tropical lowlands and coral coast of Kenting, Taiwan's southernmost point, hold the island's most purely tropical butterfly fauna — species shared with the Philippines and southeastern China. Open coastal scrub, tropical dry forest, and mangrove margins support the widest range of Pieridae, Lycaenidae, and Danaidae on the island.

Seasonal migrations

Taiwan witnesses two spectacular seasonal butterfly migrations:

Autumn Parantica migration (October–November): Several hundred thousand Parantica sitalces (Chestnut tiger) and P. aglea (Glassy tiger), large orange-and-brown milkweed glassywings, converge from across the island and funnel through the Bagua Mountain ridge and Caoling area, heading south to overwintering sites. The concentration at ridge-top mountain passes produces extraordinary aggregations visible from a few metres.

Spring Pieridae migration (March–April): Northward movement of emigrants (Catopsilia pomona, C. pyranthe), jezebels (Delias species), and common tigers (Danaus genutia) through the lowland corridors of western Taiwan marks the beginning of the butterfly season. Large numbers pause to nectar at flowering trees and shrubs.

Conservation

Taiwan has a well-developed butterfly conservation culture and a strong network of protected areas. Papilio maraho, the Troides birdwings, and several other endemic swallowtails are protected under the Wildlife Conservation Act; collection and trade are prohibited. The Butterfly Conservation Society of Taiwan runs monitoring programs across the island and manages the Purple Butterfly Valley tourism infrastructure.

The main threats to Taiwanese butterfly diversity are habitat conversion in the lowland fringe zone (urban expansion, agricultural intensification), road construction through mountain forests, and the effects of climate warming on high-altitude endemic species whose ranges are limited to a narrow altitudinal band and have nowhere higher to go.