Papilio helenus
In 3 days ~40% in a week ~70%
Papilio helenus, the red Helen, is a large swallowtail butterfly found in forests of southern India and parts of southeast Asia. Papilio helenus is rarely found in Sri Lanka, southern and north-east India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Laos, Kampuchea, Vietnam, southern China (including Hainan, Guangdong province), Taiwan, southern Japan, South Korea, Ryukyu Islands, peninsular and eastern Malaysia, Brunei, Philippines, and Indonesia (Sumatra, Java, Bangka, Kalimantan, the Lesser Sunda Islands except Tanimbar).
In India it occurs along the Western Ghats from Kerala to Gujarat, also Palnis and Shevaroys, in the north from Mussoorie eastwards, to north-east India and onto Myanmar. Male. Upper-side rich brownish-black; cilia alternated with white. Fore-wing with slender longitudinal streaks of golden-yellow scales within the cell, and hairy-scaled broad streaks between the outer veins; lower base of the wing also sparsely speckled with golden-yellow scales. Hind-wing with a cream- white upper discal patch composed of three portions, a short almost quadrate portion in the costal interspace, and two lower large elongate portions in the subcostal... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cuc Phuong National Park | 🇻🇳 Vietnam | |
| 2 | Namdapha National Park | 🇮🇳 India | |
| 3 | Sinharaja Forest Reserve | 🇱🇰 Sri Lanka | |
| 4 | Periyar National Park | 🇮🇳 India | |
| 5 | Kaeng Krachan National Park | 🇹🇭 Thailand | |
| 6 | Khao Yai National Park | 🇹🇭 Thailand | |
| 7 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 8 | Taroko National Park | 🇹🇼 Taiwan |
Possible
About 20% of wildlife watchers report a Red Helen Swallowtail sighting in Khao Yai National Park on a given day, based on 17 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 43rd most-seen of the 221 insects we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
September
In that month about 40% of wildlife watchers report a Red Helen Swallowtail in Khao Yai National Park on a given day, against under 5% in April, July and November–January, the lowest months. That is one of Khao Yai National Park's wettest months, with about 330 mm of rain against 15 mm in December.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Red Helen Swallowtail sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
6th of 8
Of the 8 parks where we can rate Red Helen Swallowtail sightings, Khao Yai National Park ranks 6th at about 20%. The best odds are in Cuc Phuong National Park (Vietnam, about 40%), Namdapha National Park (India, about 40%) and Sinharaja Forest Reserve (Sri Lanka, about 30%). All parks ranked.
Same genus: Papilio
The closest relatives of the Red Helen Swallowtail that you can see in Khao Yai National Park (genus Papilio, Common Swallowtails) are Paris Peacock Swallowtail (about 40%), Common Mormon Swallowtail (about 20%) and Great Mormon Swallowtail (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Red Helen Swallowtail is recorded against all the insects logged in Khao Yai National Park (17 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.
