Euchloe ausonides
In 3 days ~60% in a week ~90%
Euchloe ausonides, the large marble or creamy marblewing, is a species of butterfly that occurs in western North America. It lays eggs on the terminal flower buds of a variety of plants in the mustard family, including introduced Eurasian species, and the larvae feed on the buds, flowers and fruit of these plants. In California, it has witnessed population declines since the 1980s, especially in the Central Valley and the Bay Area. In Washington, subspecies the island marble butterfly (Euchloe ausonides ssp. insulanus) was listed as an endangered species under the Endangered Species Act in 2020.
The caterpillar is a dark green to a bluish gray color that is covered in black dots. It is marked with yellow and white stripes lengthwise along its back and sides. The size of the caterpillar reaches a length of 3/4 in.
The large marble is a medium-sized butterfly. It has white scales that are scattered in the forewing and a black pattern on the tip of the forewing. There is compact green marbling on the underside of the hindwing. The wingspan of this butterfly can go from 3.8 - 5.1 cm.
Females of E. ausonides are able to move at greater distances and speeds than males.... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Isle Royale National Park | 🇺🇸 United States | |
| 2 | Rocky Mountain National Park | 🇺🇸 United States | |
| 3 | Grand Teton National Park | 🇺🇸 United States | |
| 4 | Yellowstone National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Francisco | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Large Marble sighting in Isle Royale National Park on a given day, based on 14 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 12th most-seen of the 48 insects we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Large Marble 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 4 parks where we can rate Large Marble sightings, Isle Royale National Park has the highest daily chance: about 20%. Next come Rocky Mountain National Park (United States, about 10%) and Grand Teton National Park (United States, about 10%).
Same order: Lepidoptera
The closest relatives of the Large Marble that you can see in Isle Royale National Park (order Lepidoptera, Butterflies and Moths) are Red-Spotted Admiral (about 40%), North American Luna Moth (about 40%) and Northern Azure (about 40%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Large Marble is recorded against all the insects logged in Isle Royale National Park (14 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.
