Papilio thaiwanus
In 3 days ~30% in a week ~60%
Papilio thaiwanus, the Formosan swallowtail, is a butterfly in the swallowtail family. It is endemic to Taiwan. P. thaiwanus Bothsch. (= annaeus Fruhst.) (32 d female), which by a lapsus was described as a form of protenor,
is much more strikingly different in the female than in the male. Male under surface of the forewing almost entirely black,the grey stripes being reduced as in many butterflies from Formosa; the red area on the underside of the hindwing is much more extended than in the other forms and there are large red submarginal spots as far as the subcostal. The female tailless; forewing paler than in P. rhetenor; hindwing from the subcostal to the analmargin with a macular band, the anterior patches of which are large and white and the posterior ones smaller and reddish, the posterior submarginal spots united into rings with the marginal spots; under surface as in the male with larger markings than in P. rhetenor. — Formosa.
The larva feeds on Toddalia asiatica, Zanthoxylum ailanthoides, and Cinnamomum camphora. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Taroko National Park | 🇹🇼 Taiwan |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Formosan Swallowtail sighting in Taroko National Park on a given day, based on 18 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 135th most-seen of the 447 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
March, July and October
In those months about 20% of wildlife watchers report a Formosan Swallowtail in Taroko National Park on a given day, against under 5% in April–May, September and November–February, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Formosan Swallowtail sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Taroko National Park, in our data
Taroko National Park is the only park on Wallace's Line with enough records to rate Formosan Swallowtail sightings: about 10% of wildlife watchers there report one on a given day.
Same genus: Papilio
The closest relatives of the Formosan Swallowtail that you can see in Taroko National Park (genus Papilio, Common Swallowtails) are Common Mormon Swallowtail (about 20%), Spangle Swallowtail (about 20%) and Great Mormon Swallowtail (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Formosan Swallowtail is recorded against all the insects logged in Taroko National Park (18 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
