Eurema andersoni
In 3 days ~10% in a week ~30%
Eurema andersonii, the one-spot grass yellow or Anderson's grass yellow, is a small butterfly of the family Pieridae, that is, the yellows and whites, which is found in Bangladesh, India, Myanmar and other parts of Asia.
Wet form: Male. Upper-side. Fore-wing with the outer marginal band moderately broad, the medial portion inclined slightly inward, and the lower portion very slightly inclined obliquely-outward. Hind-wing with a moderately broad outer band. Underside with slightly defined ordinary markings. Fore-wing with two cell-marks, basal obsolescent. Female not seen.
Dry form (fig. 2a, b). Male. Upper-side similar to the wet form. Underside with the ordinary markings distinct. Fore-wing with a medial cell mark, and a more or less well-defined sub-apical patch. Female. Upper-side paler. Fore-wing with slightly broader outer band. Hind-wing with a moderately broad outer band. Underside similar to the male. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cat Tien National Park | 🇻🇳 Vietnam | |
| 2 | Taroko National Park | 🇹🇼 Taiwan | |
| 3 | Kaeng Krachan National Park | 🇹🇭 Thailand |
Rare
Under 5% of wildlife watchers report a One-Spot Grass Yellow sighting in Singapore on a given day, based on 55 verified sightings from GBIF citizen-science data. It is the 340th most-seen of the 1045 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
April, August, October and December–January
In those months about 10% of wildlife watchers report a One-Spot Grass Yellow in Singapore on a given day, against under 5% in February–March, May–July, September and November, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most One-Spot Grass Yellow sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 2 cities where we can rate One-Spot Grass Yellow sightings, Singapore has the highest daily chance: under 5%. Next come Taipei (Taiwan, under 5%).
Same genus: Eurema
The closest relatives of the One-Spot Grass Yellow that you can see in Singapore (genus Eurema, Grass Yellows) are Common Grass Yellow (about 10%), Chocolate Grass Yellow (about 10%) and Hill Grass Yellow (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the One-Spot Grass Yellow is recorded against all the insects logged in Singapore (55 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.
