Potamarcha congener
In 3 days ~50% in a week ~80%
Potamarcha congener is also known as the yellow-tailed ashy skimmer, common chaser, or swampwatcher. It is a species of dragonfly in the family Libellulidae, and was first described by Jules Pierre Rambur in 1842, almost fifty years before Ferdinand Karsch described its genus. Potamarcha congener is one of two species making up the genus Potamarcha, together with Potamarcha puella.
Potamarcha congener is common through much of its range, which stretches through parts of South Asia, South-East Asia, and Oceania, including in countries such as India, Indonesia, China, Australia, and Vietnam. Owing to its wide distribution, the species has been classified as Least Concern by the International Union for Conservation of Nature.
Potamarcha congener is a medium-sized dragonfly with a bluish black thorax and yellow tail with black markings. Face is olivaceous yellow to steel black or brown. Eyes are reddish brown above and bluish grey below. In male adults, the thorax and first four segments of the abdomen are covered with bluish pruinescence. In young adults, yellow markings are visible through the pruinescence. The rest of the abdomen is... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Mudumalai National Park | 🇮🇳 India | |
| 2 | Kanha National Park | 🇮🇳 India | |
| 3 | Minneriya National Park | 🇱🇰 Sri Lanka | |
| 4 | Khao Yai National Park | 🇹🇭 Thailand | |
| 5 | Kaeng Krachan National Park | 🇹🇭 Thailand |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Yogyakarta | 🇮🇩 Indonesia | |
| 2 | Raipur | 🇮🇳 India | |
| 3 | Nagpur | 🇮🇳 India | |
| 4 | Dhaka | 🇧🇩 Bangladesh | |
| 5 | Jakarta | 🇮🇩 Indonesia | |
| 6 | Kolkata | 🇮🇳 India | |
| 7 | Hyderabad | 🇮🇳 India | |
| 8 | Prayagraj | 🇮🇳 India | |
| 9 | Denpasar | 🇮🇩 Indonesia | |
| 10 | Tasikmalaya | 🇮🇩 Indonesia |
Possible
About 20% of wildlife watchers report a Swampwatcher sighting in Dhaka on a given day, based on 13 verified sightings from GBIF citizen-science data. It is the 36th most-seen of the 92 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.
June and July
In those months about 40% of wildlife watchers report a Swampwatcher in Dhaka on a given day, against under 5% in April, August and October–January, the lowest months. Those are among Dhaka's wettest months, with about 410 mm of rain a month against 10 mm in January.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Swampwatcher sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
4th of 28
Of the 28 cities where we can rate Swampwatcher sightings, Dhaka ranks 4th at about 20%. The best odds are in Yogyakarta (Indonesia, about 40%), Raipur (India, about 30%) and Nagpur (India, about 20%).
Same family: Libellulidae
The closest relatives of the Swampwatcher that you can see in Dhaka (family Libellulidae, Skimmers) are Pied Paddy Skimmer (about 40%), Scarlet Skimmer (about 40%) and Oriental Blue Dasher (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Swampwatcher is recorded against all the insects logged in Dhaka (13 verified sightings), 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.
