The milk snake or milksnake (Lampropeltis triangulum ), is a species of kingsnake; up to 24 subspecies are sometimes recognized. Lampropeltis elapsoides , the scarlet kingsnake, was formerly classified as a 25th subspecies (L. t. elapsoides ), but is now recognized as a distinct species.[2] The subspecies have strikingly different appearances, and many of them have their own common names. Some authorities suggest that this species could be split into several separate species.[2] They are not venomous to humans.[3][4]
- Coluber triangulum
Lacépède, 1788 - Pseudoëlaps Y
Berthold, 1843 - Ablabes triangulum
— A.M.C. Duméril & Bibron, 1854 - Lampropeltis triangula
— Cope, 1860 - Coronella triangulum
— Boulenger, 1894 - Osceola doliata triangula
— Cope, 1900
There is a significant amount of variation among milk snakes in terms of size. Depending on subspecies, they can be as small as 14 in (36 cm) or as large as 72 in (180 cm) long.[9] Adults in the wild apparently average from 38 to 225 g (1.3 to 7.9 oz) in North America. However, unusually large milk snakes can become rather bulkier than average-sized adults and potentially weigh up to 750 to 1,400 g (1.65 to 3.09 lb), though high weights as such are generally reported from captivity.[10][11][12] Males typically are larger than females in maturity, although females can be bulkier than males similar in length as well.[13] Generally more tropical populations, from Mexico and further south, reach larger adult sizes than milk snakes living in the temperate zones.[14]
Milk snakes have smooth and shiny scales and their typical color pattern is alternating bands of red-black-yellow or white-black-red;[2] however, red blotches instead of bands are seen in some populations.[2] Some milk snakes have a striking resemblance to coral snakes, in Batesian mimicry, which likely scares away potential predators. Both milk snakes and coral snakes possess transverse bands of red, black, and yellow. Experts now recognize that common mnemonics that people use to distinguish between the deadly coral snake and the harmless milk snake are not 100% reliable. Some coral snakes do not have the typical banding colors or patterns.[15] Examples of unreliable mnemonics commonly used:
- “Red on yellow kill a fellow. Red on black venom lack”
- “Red touches black, it’s a friend of Jack. Red touches yellow, it’s bad for a fellow.”[16]
Due to the many colors of the eastern milk snake (L. t. triangulum ), it can resemble the coral snake, corn snake, fox snake, scarlet snake, and most importantly, the venomous snake genera Agkistrodon and Sistrurus . Milk, fox, and scarlet snakes are killed because of a resemblance to the venomous pygmy rattlers. Juvenile milk snakes, which are more reddish than adults, are often killed because they are mistaken for copperheads. Enough distinction exists among the five to make the eastern milk snake fairly easy to identify. The eastern milk snakes also have a light-colored V-shaped or Y-shaped patch on their necks. One subspecies, L. t. gaigeae , is melanistic (almost all black) as an adult.[2]