Copperheads ( _Agkistrodon contortrix_ ) are a common venomous snake species found across North America, from the Florida panhandle to Massachusetts and west to Nebraska. Understanding their activity patterns throughout the year and across different times of day provides insight into their behavior.
Seasonal Activity Patterns
Copperheads exhibit distinct seasonal activity patterns. They typically emerge from winter retreats in late March or April as daytime temperatures rise. This marks the start of their active season, which generally extends through October. Early spring activity often involves basking near winter dens to raise body temperature.
Their activity peaks during the warmer summer months, particularly in August. As fall approaches and temperatures decrease, copperheads remain active, sometimes increasing movements in search of mates and preparing for winter. By late October or November, their activity declines as they transition back to overwintering sites for brumation.
Daily Activity Patterns
The daily routine of copperheads shifts depending on the season and temperatures. In cooler spring and fall periods, they are often diurnal, meaning active during daylight hours. During these seasons, they may be observed basking in the sun to absorb warmth.
As summer temperatures rise, copperheads become more crepuscular or nocturnal. This allows them to avoid intense daytime heat, hunting during cooler evening and nighttime hours. They utilize heat-sensing pits to locate prey in the dark.
Key Environmental Triggers
Temperature is a primary environmental factor dictating copperhead activity, as they are ectothermic and rely on external heat sources to regulate body temperature. Their ideal temperature range for activity is between 70°F and 90°F (21°C to 32°C), allowing for efficient hunting, digestion, and reproduction. When temperatures consistently fall below 60°F (15.5°C), copperheads become largely inactive.
Excessive heat, above 90-95°F, causes them to seek shelter or become nocturnal to prevent overheating. Rainfall also influences their activity, especially on warm, humid nights, as it encourages prey (such as rodents and amphibians) to be more active. The increased availability of food after a warm rain can lead to heightened hunting activity.
Winter Retreat
During colder months, copperheads enter a state called brumation, which differs from true hibernation in mammals. Brumation involves reduced activity and slowed metabolism, though copperheads may still emerge on unusually warm winter days to bask or seek water. This dormancy typically begins in late October or November and lasts until late March or early April, depending on geographic location and winter severity.
Copperheads often seek communal dens, known as hibernacula, for brumation. These sites provide insulation and protection from freezing temperatures and can include rocky crevices, abandoned burrows, tree root systems, or human-made structures like sheds. They frequently return to the same den year after year, sometimes sharing these spaces with other snake species.