Troides aeacus
In 3 days ~50% in a week ~80%
Troides aeacus, the golden birdwing, is a large tropical butterfly belonging to the swallowtail family, Papilionidae. Troides aeacus has a wingspan of about 150–170 millimetres (5.9–6.7 in) but can be as large as 194 mm. In the males the forewings are black, with veins bordered by a whitish colour, while the hindwings are bright yellow. The underside of the wings is quite similar to the upside. The females are larger than the males and have dark-brown or black wings. The head, thorax and abdomen of this butterfly are mainly black, with small red patches on the thorax and a yellow underside of the abdomen. Caterpillars are pale brown, with long protrusions resembling thorns. They mainly feed on Aristolochia and Thottea species (Aristolochiaceae).
Troides aeacus closely resembles Troides helena cerebrus and differs as follows: Upperside, forewing: the pale adnervular streaks more prominent, in some specimens extended into the cell along the outer half of the subcostal and of the median nervules.
Hindwing: the cone-shaped terminal black markings in interspaces 2, 3, and 4 more or less broadly bordered on the inner side by a dusky area that is irrorated with blackish... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cuc Phuong National Park | 🇻🇳 Vietnam | |
| 2 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 3 | Khao Yai National Park | 🇹🇭 Thailand | |
| 4 | Kaeng Krachan National Park | 🇹🇭 Thailand | |
| 5 | Taroko National Park | 🇹🇼 Taiwan |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Phnom Penh | 🇰🇭 Cambodia | |
| 2 | Guwahati | 🇮🇳 India | |
| 3 | Ho Chi Minh City | 🇻🇳 Vietnam | |
| 4 | Bangkok | 🇹🇭 Thailand | |
| 5 | Kuala Lumpur | 🇲🇾 Malaysia | |
| 6 | Hong Kong | 🇨🇳 China | |
| 7 | Singapore | 🇸🇬 Singapore |
Possible
About 20% of wildlife watchers report a Golden Birdwing sighting in Cat Tien National Park on a given day, based on 19 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 31st most-seen of the 125 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
February
In that month about 40% of wildlife watchers report a Golden Birdwing in Cat Tien National Park on a given day, against under 5% in July to January, the lowest months. That is one of Cat Tien National Park's driest months, with about 15 mm of rain against 490 mm in July.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Golden Birdwing sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 parks where we can rate Golden Birdwing sightings, Cat Tien National Park ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Cuc Phuong National Park (Vietnam, about 20%).
GBIF citizen-science records
It is estimated from how often the Golden Birdwing is recorded against all the insects logged in Cat Tien National Park (19 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.
