Brachydiplax chalybea
In 3 days ~20% in a week ~50%
Brachydiplax chalybea is a species of dragonfly in the family Libellulidae. It is known by the common names yellow-patched lieutenant, rufous-backed marsh hawk, and blue dasher. It is native to much of eastern Asia, from India to Japan to Indonesia.
The male of the species is 33 to 35 millimeters long and has a hindwing 24 to 27 millimeters long. It is powder blue with light brown sides and a dark tip to the abdomen. Wings are hyaline, with tinted burnt-brown base, fading to amber. The female is brownish yellow in color with darker markings along the dorsal abdomen. Its wings lack the yellow tinge. This species can be easily distinguished from other species in this genus by its larger size, characteristic colour of the thorax, and bases of wings.
This species is found in many types of wet habitat, including brackish and disturbed waters. The males are seen more often, due to their territorial behavior. Females oviposit by "flicking" an egg mass out of the water into rocks and vegetation nearby.
Brachydiplax chalybea of Borneo Island Data related to Brachydiplax chalybea at Wikispecies Media related to Brachydiplax... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sundarbans National Park | 🇮🇳 India | |
| 2 | Sepilok | 🇲🇾 Malaysia | |
| 3 | Kinabatangan Wildlife Sanctuary | 🇲🇾 Malaysia | |
| 4 | Khao Sok National Park | 🇹🇭 Thailand | |
| 5 | Kaeng Krachan National Park | 🇹🇭 Thailand |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dhaka | 🇧🇩 Bangladesh | |
| 2 | Kochi | 🇮🇳 India | |
| 3 | Thrissur | 🇮🇳 India | |
| 4 | Ponnani | 🇮🇳 India | |
| 5 | Kolkata | 🇮🇳 India | |
| 6 | Kozhikode | 🇮🇳 India | |
| 7 | Bangkok | 🇹🇭 Thailand | |
| 8 | Yogyakarta | 🇮🇩 Indonesia | |
| 9 | Thiruvananthapuram | 🇮🇳 India | |
| 10 | Johor Bahru | 🇲🇾 Malaysia |
With luck
About 10% of wildlife watchers report an Oriental Blue Dasher sighting in Kaeng Krachan National Park on a given day, based on 11 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 127th 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 50%, if each day is a fresh chance.
April
In that month about 20% of wildlife watchers report an Oriental Blue Dasher in Kaeng Krachan National Park on a given day, against under 5% in January–February, May and July–October, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Oriental Blue Dasher sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
5th of 5
Of the 5 parks where we can rate Oriental Blue Dasher sightings, Kaeng Krachan National Park ranks 5th at about 10%. The best odds are in Sundarbans National Park (India, about 40%), Sepilok (Malaysia, about 20%) and Kinabatangan Wildlife Sanctuary (Malaysia, about 20%).
GBIF citizen-science records
It is estimated from how often the Oriental Blue Dasher is recorded against all the insects logged in Kaeng Krachan National Park (11 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.
