The Queen snake (Regina septemvittata) is a nonvenomous semiaquatic snake, native to North America. They are active during the day and are often found among rocks or near streams and often come out of the water to warm in the sun.
The Queen snake is olive to gray or dark brown in overall coloration, with peach or yellow stripes that run down its length at the first scale row. There are also four prominent ventral stripes of a darker color, and as no other similar species has stripes running down the length of its belly, this is an important feature in identifying this snake. In the young and juvenile snakes, there are three extra stripes: one stripe that runs along the vertebral dorsal scales, and two stripes (one on each side) that run down the length of the body at scale rows five and six. These extra stripes tend to fade as the snake matures, but when young the snake will have a total of seven stripes, three on the back and four on the belly; this has led to its taxonomical reference name, Regina (queen) septemvittata (seven-striped). The belly of the snake is a cream to yellow color. The females in this species are generally slightly larger than the males.
Queen snakes range through the temperate region of North America east of the Mississippi River from western New York state to Wisconsin and south to Alabama and northern Florida. They are also found in the southwestern parts of Ontario. These snakes are never found in areas that lack clean running streams and watersheds with stony and rocky bottoms. They inhabit ponds, edges of lakes, ditches, canals, creeks, marshes and can also be found in agricultural and urban areas.
Queen snakes are diurnal creatures, but they can be found moving about and hunting at night as well. They are often found by turning over rocks within or near the brooks and streams they inhabit. They will also come out of the water to bask in the sun, often perching on branches or roots above or near the waters edge. Queen snakes do not find their food by sight or heat detection; they hunt by smell, using their tongue to carry the scent of the prey to receptors within their mouth. In this way, they are able to home in on their prey, even under water. Queen snakes are very alert to any potential danger and will drop into the water when disturbed. They are rather docile snakes, not too likely to bite, and can be easily handled. During the winter Queen snakes are in a period of brumation (hibernation), and groups of them can be found in "hibernacula", near water. These hibernation dens can be inside old bridge abutments, cracked concrete retaining walls, and dams, and in niches of bedrock.
Queen snakes are carnivores and feed mainly on freshwater crayfish. Their diet also includes frogs, tadpoles, newts, minnows, snails, and fairy shrimp.
Queen snakes are polygynous meaning that males mate with multiple females. Breeding takes place in the spring and autumn months. If mating was in the autumn, the female can delay giving birth till spring, storing the energy she will need through the months that she will be in a period of brumation. Queen snakes are ovoviviparous and females give birth to live young after carrying the eggs within their body. The gestation period lasts 90 to 120 days and litter size can vary from 5 to 20 snakelets. The newly born snakes will be approximately 6 in (15 cm) long and weigh 0.1 ounces (2.8 g). They begin to grow very rapidly and may shed their skin twice in their first week while living on the nutrient-rich yolk stores they preserve through this time in their lives. The baby snakes are able to swim and move about and they must fend for themselves independently directly after birth. Juvenile Queen snakes range from 17.5 to 23 cm (6.9 to 9.1 in) in length; females will be fully reproductively mature at three years of age, males at two years.
The main threat to Queen snakes is habitat loss as waterways are drained, disturbed, or polluted. Crayfish, their main food, are sensitive to acidification and accumulation of heavy metals. Thus, as waterways have become polluted and crayfish have died out, the Queen snake population has declined throughout its former range. In many areas, Queen snakes have disappeared or have become in danger of doing so. Other important reasons for their decline are persecution by humans and illegal collection for the pet trade.
The IUCN Red List and other sources don’t provide the number of the Queen snake total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Queen snakes are important predators of crayfish and thus control their populations. They are also a food source for many local predators including raccoons, otters, mink, hawks, and herons. Large frogs and fish will also eat young snakes.