Glaucopsyche piasus
In 3 days ~10% in a week ~30%
Glaucopsyche piasus, the arrowhead blue, is a western North American butterfly of the family Lycaenidae. It is a locally common butterfly that favors prairie, open woodland, and woodland edges and trails. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Yellowstone National Park | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report an Arrowhead Blue sighting in Yellowstone National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 118th most-seen of the 160 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.
June and July
In those months about 10% of wildlife watchers report an Arrowhead Blue in Yellowstone National Park on a given day, against under 5% in August to May, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Arrowhead Blue sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 2
Of the 2 parks where we can rate Arrowhead Blue sightings, Yellowstone National Park ranks 2nd at under 5%. The best odds are in Sequoia and Kings Canyon National Parks (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Arrowhead Blue is recorded against all the insects logged in Yellowstone 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.
