Invertebrates
Common Buckeye
Junonia coenia · also called common buckeyes
Basking with wings spread flat on a sunny gravel path, a common buckeye flashes six large false eyespots, a startling display aimed squarely at convincing any approaching predator that this small butterfly is something considerably bigger and more dangerous than it actually is.
Overview
The common buckeye, Junonia coenia, is a boldly patterned butterfly native to open grassland, fields, and other disturbed habitat across a very broad range spanning most of the United States and parts of Mexico. Its six prominent false eyespots, conspicuous ground-basking behaviour, and seasonal north-south movements make it one of the more visually striking and easily observed butterflies in North America.
Six eyes that aren’t really eyes
Every one of the common buckeye’s six wing eyespots is a bluff, a purely visual trick that borrows the unsettling appearance of a much larger animal’s eyes to buy the butterfly a crucial extra moment against an approaching predator.
Status
Least Concern — widespread and common across suitable open grassland and disturbed habitat throughout most of North America.
Common Buckeye: common questions
Why does the common buckeye have such large eyespots?
This species' six prominent false eyespots are thought to serve one of two possible defensive functions, either startling an approaching predator with their sudden, vivid appearance or directing an attack toward the less vulnerable wing margin rather than the butterfly's actual body, both of which could improve its odds of surviving an encounter with a predator.
Does the common buckeye migrate like the monarch butterfly?
This species does undertake seasonal movements in parts of its range, generally moving northward during warmer months and retreating south as conditions cool, but this pattern is considerably less structured and well-documented than the monarch butterfly's famous multi-generational migration route.
Where can you usually find a common buckeye?
This species frequently basks with its wings spread flat on bare ground, gravel paths, or low vegetation within open grassland and disturbed habitat, a conspicuous basking behaviour that makes it one of the easier butterflies to observe and photograph up close.
What does the common buckeye caterpillar eat?
This species' caterpillar feeds on plantain, snapdragon relatives, and other low-growing plants commonly found in the open grassland and disturbed habitat the adult butterfly also favours, a host plant range broad enough to support the species across a very wide geographic distribution.