Louisiana Pinesnake

Dorsally, the color is buff or lion-like yellow with dark brown blotches and spots that are very similar throughout the body. The marking patterns are visibly different from one end to another. The neck region is "busier", the dark reticulates and blends more with the lighter coloration. Towards midbody, the dark markings become more distinct and contrasting, and continue to be more distinct toward the tail, yet reduced in marking thickness. These markings number 28-42 middorsally. Furthermore, the very pointed head may only be marked slightly with some small dots and a faded bar in front and between the orbitals above. The ventrals never appear to be immaculate, but are intermediately blotched with brown. Nevertheless, there usually is no true checkered pattern. The rostral scale is exceptionally large, and usually 8 or 9 supralabials and from about 10-15 (generally 14) infralabials are present.

The Louisiana pine snake is generally associated with sandy, well-drained soils; open pine forests, especially longleaf pine savannas; moderate to sparse midstory; and a well-developed herbaceous understory dominated by grasses. Its activity appears to be heavily concentrated on low, broad ridges overlain with sandy soils. Baird's pocket gophers appear to be an essential component of their habitat. They create the burrow systems in which the pine snakes are most frequently found, and serve as a major source of food for the species. Up to 90% of radio-tagged snake relocations have been underground in pocket gopher burrow systems, and movement patterns are typically from one pocket gopher burrow system to another. Snakes disturbed on the surface retreated to nearby burrows, and hibernation sites were always within burrows. Both native and captive-released snakes were found most frequently in areas containing an ample number of pocket gopher mounds, and snakes stayed active longer and moved greater distances where pocket gopher burrows were abundant. Pocket gopher abundance is dependent upon an abundance of herbaceous groundcover and loose, sandy soils. The amount of herbaceous vegetation is related to canopy cover. Generally, a rich ground layer requires a high degree of solar penetration into the forest floor. …

Growth is rapid; snakes may reach 2–3 ft (61–91 cm) in total length at 1 year and 3–4 ft (91–122 cm) at 2 years. The largest reported specimen was 5.8 ft (180 cm) in total length. Sexual maturity may be attained at a minimal total length of 4 ft (120 cm) and an age of at least 3 years. The species is oviparous, with a gestation period around 21 days, followed by 60 days of incubation. This species exhibits a remarkably low reproductive rate, which magnifies other threats to the Louisiana pine snake. It has the smallest clutch size (three to five) of any North American colubrid and the largest eggs, generally 5 in (13 cm) long by 2 in (5.1 cm) wide, of any snake in the United States. It also produces the largest hatchlings reported for any North American snake, ranging 18–22 in (46–56 cm) in total length, and up to 0.8 oz (23 g) in weight. The large size of the pine snake hatchlings may be an adaptation to enable young to feed relatively early.

The species was first described by Olive Griffith Stull in 1929 as a subspecies of P. melanoleucus. In 1940, the Louisiana pine snake was promoted to the rank of species in another of Stull's articles. Its scientific name honors Alexander Grant Ruthven, the late herpetologist of the University of Michigan Museum of Zoology.