Junonia coenia
In 3 days ~50% in a week ~80%
Junonia coenia, known as the common buckeye or buckeye, is a butterfly in the family Nymphalidae. It is found as a resident or vagrant across much of North America and Central America, as well as in parts of northern South America. This includes most of the eastern half of the US, the lower to middle Midwest, the Southwest (including most of California), southern Canada, and Mexico. Its habitat includes fields, dunes and scrub, typically in sunny environments up to 1,300 metres (4,300 ft) in altitude. It can be found in open areas with low vegetation and some bare ground. Its original ancestry has been traced to Africa, which then experienced divergence in Asia. The species Junonia grisea, the gray buckeye, is found west of the Rocky Mountains and was formerly a subspecies of Junonia coenia.
Caterpillars of these butterflies appear to prefer plants that produce iridoid glycosides, which are bitter compounds that release a hormone called gastrin that activates the digestive system (i.e. hunger); therefore, iridoid glycoside producing plants stimulate and attract their appetites particularly when found in plants like Plantago lanceolata. In fact, the presence of these metabolites may trigger oviposition behaviors in female butterflies so that descendant larval bodies may better incorporate iridoid glycosides. Iridoid glycolyside metabolites appear to have a growth-stimulating effect on caterpillars but a growth-reducing effect on predators. Predators like ants, wasps, birds, and small animals prefer to feed on iridoid glycoside poor caterpillars rather than iridoid glycoside rich larvae, potentially due to these effects. Therefore, immunity of J. coenia larvae to predators like ants appears to be strongly related to the concentration of iridoid glycosides sequestered in their bodies. However, too much iridoid glycosides in the diet can negatively affect the immune response of these larvae and lead to increased susceptibility to parasitism.
Adult butterflies feed on flowers with certain pollinator cues: yellow flowers that are "pre-change", or flowers whose color has not been changed due to insect visitation or other factors. Common buckeye caterpillars feed in isolation rather than relying upon grouping behaviors. Vulnerability to the Junonia coenia densovirus is another concern for survivorship of common buckeye larvae. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Padre Island National Seashore | 🇺🇸 United States | |
| 2 | Congaree National Park | 🇺🇸 United States | |
| 3 | Big Cypress National Preserve | 🇺🇸 United States | |
| 4 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 5 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 6 | Point Pelee National Park | 🇨🇦 Canada | |
| 7 | Big Bend National Park | 🇺🇸 United States | |
| 8 | Everglades National Park | 🇺🇸 United States | |
| 9 | Shenandoah National Park | 🇺🇸 United States | |
| 10 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dallas | 🇺🇸 United States | |
| 2 | Austin | 🇺🇸 United States | |
| 3 | San Antonio | 🇺🇸 United States | |
| 4 | Baltimore | 🇺🇸 United States | |
| 5 | Houston | 🇺🇸 United States | |
| 6 | Washington | 🇺🇸 United States | |
| 7 | Chicago | 🇺🇸 United States | |
| 8 | Philadelphia | 🇺🇸 United States | |
| 9 | Puebla | 🇲🇽 México | |
| 10 | New York City | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Common Buckeye sighting in Merritt Island National Wildlife Refuge on a given day, based on 78 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 14th most-seen of the 189 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.
March–April and October
In those months about 30% of wildlife watchers report a Common Buckeye in Merritt Island National Wildlife Refuge on a given day, against about 10% in May, July–August and December–January, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Common Buckeye sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
5th of 10
Of the 10 parks where we can rate Common Buckeye sightings, Merritt Island National Wildlife Refuge ranks 5th at about 20%. The best odds are in Padre Island National Seashore (United States, about 40%), Congaree National Park (United States, about 20%) and Big Cypress National Preserve (United States, about 20%).
GBIF citizen-science records
It is estimated from how often the Common Buckeye is recorded against all the insects logged in Merritt Island National Wildlife Refuge (78 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.
