Serrognathus titanus
In 3 days ~30% in a week ~50%
Serrognathus titanus is a species of beetle in the family Lucanidae. It was described by Jean Baptiste Boisduval in 1835. Huang and Chen (2013) separated Serognathus from the genus Dorcus by representing morphological characters and DNA analysis.
Males measure 32.0–111.3 millimetres (1.26–4.38 in) including mandibles; females 36.5–54 millimetres (1.44–2.13 in). It has an elongated, somewhat flat body dull black with blackish antennae and legs. Male's antler-like jaws have small teeth along inner edge and a pair of big teeth toward the bottom, and are forked at end. The head of a large male reaches nearly the length of its prothorax and abdomen combined.
Adults can be seen from May to August. They feed on tree juice, especially of Quercus species. Females lay eggs on the underground part of fallen oaks. The eggs hatch in about a month and the larvae feed on rotten wood. The larval period lasts about one year. The complete life cycle can last approximately from 1 to 2 years.
This species is widely distributed in Indonesia, the Philippines, Malaysia, Thailand, Vietnam, Laos, Myanmar, India, Japan, China, Taiwan and Korea. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Taroko National Park | 🇹🇼 Taiwan | |
| 2 | Khao Yai National Park | 🇹🇭 Thailand | |
| 3 | Kinabalu Park | 🇲🇾 Malaysia |
With luck
About 10% of wildlife watchers report a Titan Stag Beetle sighting in Khao Yai National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 115th most-seen of the 221 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
September
In that month about 30% of wildlife watchers report a Titan Stag Beetle in Khao Yai National Park on a given day, against under 5% in June and November–April, 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 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Titan Stag Beetle sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 3
Of the 3 parks where we can rate Titan Stag Beetle sightings, Khao Yai National Park ranks 2nd at about 10%. The best odds are in Taroko National Park (Taiwan, about 20%).
Same family: Lucanidae
The closest relatives of the Titan Stag Beetle that you can see in Khao Yai National Park (family Lucanidae, Stag Beetles) are Odontolabis mouhoti (about 10%), Odontolabis siva (about 10%) and Dorcus ritsemae (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Titan Stag Beetle is recorded against all the insects logged in Khao Yai National Park (7 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.
