Lethe europa
In 3 days ~20% in a week ~40%
Lethe europa, otherwise known as the bamboo treebrown, is a species of Satyrinae butterfly found in Asia. The inner third of the hindwing is covered with long brown hairs. The upper side is a rich dark brown, with the forewing showing through a short oblique white discal fascia from the underside. This is accompanied by two obscure black ocelli, followed by two prominent white spots, the upper of which is double. Black markings occur along the terminal margins of both forewing and hindwing, outwardly bordered with pale dusky brown, with an obscure subterminal pale line on the hindwing.
The underside is a very dark blackish brown. Both wings are crossed sub-basally by a slender lilacine-white straight line, followed on the forewing by an oblique short white discla fascia. A postdiscal series of large black ocelli is present on both wings, with a terminal narrow ochraceous band bordered internally by a silvery-purple line. These ocelli are further bordered by inwardly and outwardly curving silvery-purple lunular lines; on the forewing these curve inward, while on the hindwing they curve outward. The forewing ocelli are confluent, black, and without pupils... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Kanha National Park | 🇮🇳 India | |
| 2 | Taroko National Park | 🇹🇼 Taiwan | |
| 3 | Kaeng Krachan National Park | 🇹🇭 Thailand |
With luck
About 10% of wildlife watchers report a Bamboo Treebrown sighting in Kaeng Krachan National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 172nd most-seen of the 296 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Bamboo Treebrown in Kaeng Krachan National Park on a given day, against under 5% in January, April–May, July and September–November, the lowest months. That is one of Kaeng Krachan National Park's wettest months, with about 200 mm of rain against 30 mm in December.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Bamboo Treebrown sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 parks where we can rate Bamboo Treebrown sightings, Kaeng Krachan National Park ranks 3rd at about 10%. The best odds are in Kanha National Park (India, about 20%) and Taroko National Park (Taiwan, about 10%).
Same family: Nymphalidae
The closest relatives of the Bamboo Treebrown that you can see in Kaeng Krachan National Park (family Nymphalidae, Brush-footed Butterflies) are Marbled Map (about 30%), Dark Blue Tiger (about 30%) and Rustic (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Bamboo Treebrown is recorded against all the insects logged in Kaeng Krachan National Park (9 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.
