Louisiana Pine Snake
Encyclopedia
The Louisiana Pine Snake (Pituophis ruthveni) is a large, nonvenomous constrictor of the Colubridae family. This powerful snake is notable because if its large eggs and small clutch sizes. The Louisiana Pine Snake is indigenous to west-central Louisiana
and eastern Texas
, where it relies strongly on the Baird's Pocket Gopher
for its burrow system and as a food source. The Louisiana Pine Snake is rarely seen in the wild and is considered to be one of the rarest snakes in North America. The demise of the species is due its low fecundancy coupled with the extensive loss of suitable habitat - the Longleaf Pine
savannas
in the Gulf coastal plain
of the southeastern United States
. Management activities are being conducted to promote the species' recovery.
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 G. Ruthven, the late herpetologist of the University of Michigan Museum of Zoology.
, with a gestation period of about 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 (3-5) of any North American colubrid and the largest eggs (generally 5 inches or 12.7 cm long and 2 inches or 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 (45.7–55.9 cm) in length, and up to 0.8 ounces (22.7 g) in weight. The large size of the pine snake hatchlings may be an adaptation to enable young to feed relatively early.
Seasonally, Louisiana Pine Snakes were most active March-May and fall (especially November) and least active during hibernation in December-February, and in summer (especially August). Their below-ground refuges were almost exclusively Baird's Pocket Gopher
(Geomys breviceps) burrow systems. Pocket gophers also appear to be their primary food source, but other reported food items include other rodents, cottontails, amphibians, and ground-nesting birds and eggs.
Their annual home range varied from 12 acres (4.9 ha) (juveniles) to 195 acres (78.9 ha) in size, and averaged 69 acres (27.9 ha). Adult males had larger home ranges (145 acres or 58.7 ha) than females (25 acres or 10.1 ha). Pine snakes in east Texas usually moved less than 33 feet (10.1 m) daily. However, when snakes did move longer distances, usually from one pocket gopher burrow system to a new one, the average daily distance moved was 669 feet for adult females and 568 feet (173.1 m) for adult males; in Louisiana, males moved an average of 492 feet (150 m), and females 344 feet (104.9 m). Males tended to make long moves in May-July, while females moved primarily in July-September. There was no indication of seasonal migration.
, especially Longleaf Pine
savanna; 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 Louisiana Pine Snake 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 onto the forest floor. Pocket gopher abundance was associated with a low density of trees and an open canopy, which allowed greater sunlight, more understory growth, and better forage for pocket gophers.
parishes and fourteen Texas
counties, coinciding with a disjunctive portion of the Longleaf Pine
ecosystem
west of the Mississippi River
. They are now found in only four Louisiana parishes and five Texas counties. In Texas, records confirm their presence only in the southern portion of Sabine National Forest
(Sabine County) and adjacent private land (Newton County
), and in the southern portion of Angelina National Forest
(Angelina
, Jasper, Tyler counties). Nearly all recent records are from two separate areas, each measuring less than 4 miles (6.4 km) in radius, and a third site (Scrappin' Valley) managed by Temple-Inland Corporation in northern Newton County. Most Louisiana records originate in Bienville Parish
on privately owned forestland. A second population occurs on federal lands in Vernon Parish
(Fort Polk
, U.S. Army, and Kisatchie National Forest
). An apparently third population has been found near the juncture of Vernon, Sabine
and Natchitoches
parishes.
Studies suggest that extensive population declines and local extinction
s of the Louisiana Pine Snake have occurred during the last 50-80 years. A habitat assessment of known historical localities found that only 34% were still considered capable of supporting a viable population of pine snakes. The species has not been documented in over a decade in some of the best remaining habitat within its historical range, suggesting extinction or extreme rarity. It is now recognized as one of the rarest snakes in North America, and one of the rarest vertebrate species in the United States.
and Shortleaf Pine ecosystem. Virtually all timber in the South was cut during intensive commercial logging from 1870 to 1920. In 1935, only 3% of remaining Longleaf Pine forests in Louisiana and Texas existed as uncut, old-growth stands. In the 1980's, only 15% in Louisiana and 7% in Texas of the 1935 levels of natural Longleaf Pine forest still remained. The majority of this historic Longleaf and Shortleaf pine savanna forests has been replaced with plantations of fast-growing Loblolly
and Slash Pine
. These commercial plantations are typically grown in very dense, closed-canopy stands that are harvested on short rotations of less than 40 years. These forests have sparse and poorly structured understory
plant communities, rendering them uninhabitable for pocket gophers.
s. The suppression of natural fire events may represent the greatest threat to the Louisiana Pine Snake in recent years, decreasing both the quantity and quality of habitat available to pine snakes. The Longleaf Pine savanna forest evolved as a fire climax
community, adapted to the occurrence of frequent, but low-intensity, ground fires. These natural fire events on sandy, well-drained soils typically maintained an overstory dominated by Longleaf Pine, with minimal midstory cover but a well-developed understory of native bunch grasses and herbaceous plants. These park-like forests supported ideal habitat for pocket gophers and, subsequently, pine snakes.
In the absence of periodic fires, these upland pine savanna ecosystems rapidly develop a dense mid-story which suppresses or eliminates any herbaceous understory. Since the presence of pocket gophers is directly related to the extent of herbaceous vegetation available to them, their population numbers and distribution declines as such vegetation declines. No pine snakes have been captured in areas substantially degraded by fire suppression. Observations indicate that pine snakes are well adapted to fire. Aboveground snakes quickly move into pocket gopher burrows as flames come near. Nine pine snakes residing in areas subjected to prescribed burns over three years time all survived with no damage.
. Motorized vehicles have eliminated a large part of the Millstead Branch bog community and the Catahoula Barrens community. In Sabine National Forest
, vehicle conflicts occur on Foxhunter's Hill and the Stark Tract.
, whose abundance in turn depends on the understory
plants and loose, sandy soil of the Longleaf Pine
savannas. In March 2004, eight state and federal agencies signed a landmark Candidate Conservation Agreement to protect the Louisiana Pine Snake on federal lands in Texas and Louisiana. Organizations participating in the effort include: Fort Polk Military Installation, Kisatchie National Forest
, National Forests in Texas, Louisiana Department of Wildlife and Fisheries, Texas Parks and Wildlife Department
, United States Fish and Wildlife Service
's Southeast and Southwest Regions, and United States Forest Service
's Southern Research Station. The voluntary agreement provides a way for the agencies to collaborate on projects to avoid and minimize impacts to the snake. The agreement also sets up a mechanism to exchange information on successful management practices and to coordinate research efforts. Fire is central to the recovery effort. Without fire, these upland pine savanna ecosystems rapidly develop a mid-story that excludes the herbaceous understory needed by pocket gophers. When gopher populations decline, so do those of the pine snake.
The management actions proposed by the partners in the agreement are designed to restore and protect the remaining Longleaf Pine forests of east Texas and western Louisiana. Frequent, low-intensity ground fires are required to maintain the open midstory of these forests; many of the plants must literally be burnt to reproduce or grow. Longleaf Pine forests are very special habitats, being among the most biologically diverse ecosystems outside the tropics. Over 30 plant and animal species associated with Longleaf Pine ecosystems are endangered or species of concern.
The American Zoo and Aquarium Association manages a Species Survival Plan
for the Louisiana Pine Snake, headquartered at the Memphis Zoo
. The Species Survival Plan insures that the precious captive population maintained in zoos, which sits precariously at less than 100 individuals, is managed wisely and for the long term.
[NOTE: Unless otherwise stated, the principal source of material presented here was: U.S. Fish and Wildlife Service: Louisiana pine snake (cited above). That work was summarized from an extensive literature review presented in: Candidate Conservation Agreement for the Louisiana Pine Snake (cited above). Users desiring more detailed, referenced material should consult the literature review.]
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
and eastern Texas
East Texas
East Texas is a distinct geographic and ecological area in the U.S. state of Texas.According to the Handbook of Texas, the East Texas area "may be separated from the rest of Texas roughly by a line extending from the Red River in north central Lamar County southwestward to east central Limestone...
, where it relies strongly on the Baird's Pocket Gopher
Baird's Pocket Gopher
Baird’s Pocket Gopher or Louisiana Pocket Gopher is a species of pocket gopher that is native to the Southern United States. In total, there are three almost identical species of eastern pocket gopher; Geomys attwateri, Geomys bursarius, and Geomys breviceps...
for its burrow system and as a food source. The Louisiana Pine Snake is rarely seen in the wild and is considered to be one of the rarest snakes in North America. The demise of the species is due its low fecundancy coupled with the extensive loss of suitable habitat - the Longleaf Pine
Longleaf Pine
Pinus palustris, commonly known as the Longleaf Pine, is a pine native to the southeastern United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida....
savannas
Eastern savannas of the United States
The eastern savannas of the United States covered large portions of the east side of the continent until the early 20th century. These were in a fire ecology of open grassland and forests with low ground cover of herbs and grasses....
in the Gulf coastal plain
Gulf Coastal Plain
The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico.The plain reaches from the western Florida Panhandle, the southwestern two thirds of Alabama, over most of Mississippi, some of western Tennessee and Kentucky, southwest Arkansas, the Florida...
of the southeastern United States
Southeastern United States
The Southeastern United States, colloquially referred to as the Southeast, is the eastern portion of the Southern United States. It is one of the most populous regions in the United States of America....
. Management activities are being conducted to promote the species' recovery.
Taxonomy
The species was first described by Olive Griffith StullOlive Griffith Stull
Olive Griffith Stull was an American herpetologist.Stull was born February 10, 1905, in Rochester, New York. She married Loy Davis in 1930, one year after completing her degree at the University of Michigan. She worked in the field of veterinary medicine and contributed to research in a variety of...
in 1929 as a subspecies of P. melanoleucus
Pituophis melanoleucus
Pituophis melanoleucus is a harmless colubrid species found in the United States. Three subspecies are currently recognized, including the nominate subspecies described here.-Description:...
. In 1940, the Louisiana Pine Snake was promoted to the rank of species in another of Stull's articles. Its scientific name honors Alexander G. Ruthven, the late herpetologist of the University of Michigan Museum of Zoology.
Description
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 the mid-body, 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 there are usually 8 or 9 supralabials and from about 10-15 (generally 14) infralabials.Growth and reproduction
Growth is rapid; snakes may reach 2–3 ft (61–91.4 cm) in length at 1 year and 3–4 ft (91.4–121.9 cm) feet at 2 years. The largest reported specimen was 5.8 feet (176.8 cm) long. Sexual maturity may be attained at a minimal total length of 4 feet (121.9 cm) and an age of at least 3 years. The species is oviparousOviparity
Oviparous animals are animals that lay eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, reptiles, all birds, the monotremes, and most insects, some molluscs and arachnids....
, with a gestation period of about 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 (3-5) of any North American colubrid and the largest eggs (generally 5 inches or 12.7 cm long and 2 inches or 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 (45.7–55.9 cm) in length, and up to 0.8 ounces (22.7 g) in weight. The large size of the pine snake hatchlings may be an adaptation to enable young to feed relatively early.
Behavior
In studies in east Texas and west Louisiana, the snakes spent at least 60% of their time below-ground, exhibiting only short-range movements of 10–20 ft (3–6.1 m). Snakes were most active late-morning and mid-afternoon, and least active at night and early morning. Above-ground snakes usually moved underground at least once during the day, possibly for foraging, body cooling, or predator avoidance. Hibernation sites were always within pocket gopher burrow systems.Seasonally, Louisiana Pine Snakes were most active March-May and fall (especially November) and least active during hibernation in December-February, and in summer (especially August). Their below-ground refuges were almost exclusively Baird's Pocket Gopher
Baird's Pocket Gopher
Baird’s Pocket Gopher or Louisiana Pocket Gopher is a species of pocket gopher that is native to the Southern United States. In total, there are three almost identical species of eastern pocket gopher; Geomys attwateri, Geomys bursarius, and Geomys breviceps...
(Geomys breviceps) burrow systems. Pocket gophers also appear to be their primary food source, but other reported food items include other rodents, cottontails, amphibians, and ground-nesting birds and eggs.
Their annual home range varied from 12 acres (4.9 ha) (juveniles) to 195 acres (78.9 ha) in size, and averaged 69 acres (27.9 ha). Adult males had larger home ranges (145 acres or 58.7 ha) than females (25 acres or 10.1 ha). Pine snakes in east Texas usually moved less than 33 feet (10.1 m) daily. However, when snakes did move longer distances, usually from one pocket gopher burrow system to a new one, the average daily distance moved was 669 feet for adult females and 568 feet (173.1 m) for adult males; in Louisiana, males moved an average of 492 feet (150 m), and females 344 feet (104.9 m). Males tended to make long moves in May-July, while females moved primarily in July-September. There was no indication of seasonal migration.
Habitat
The Louisiana Pine Snake is generally associated with sandy, well-drained soils; open pine forestsPiney Woods
The Piney Woods is a temperate coniferous forest terrestrial ecoregion in the Southern United States covering of East Texas, southern Arkansas, western Louisiana, and southeastern Oklahoma. These coniferous forests are dominated by several species of pine as well as hardwoods including hickory and...
, especially Longleaf Pine
Longleaf Pine
Pinus palustris, commonly known as the Longleaf Pine, is a pine native to the southeastern United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida....
savanna; 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 Louisiana Pine Snake 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 onto the forest floor. Pocket gopher abundance was associated with a low density of trees and an open canopy, which allowed greater sunlight, more understory growth, and better forage for pocket gophers.
Distribution and status
Louisiana Pine Snakes originally occurred in at least nine LouisianaLouisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...
parishes and fourteen Texas
East Texas
East Texas is a distinct geographic and ecological area in the U.S. state of Texas.According to the Handbook of Texas, the East Texas area "may be separated from the rest of Texas roughly by a line extending from the Red River in north central Lamar County southwestward to east central Limestone...
counties, coinciding with a disjunctive portion of the Longleaf Pine
Longleaf Pine
Pinus palustris, commonly known as the Longleaf Pine, is a pine native to the southeastern United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida....
ecosystem
Piney Woods
The Piney Woods is a temperate coniferous forest terrestrial ecoregion in the Southern United States covering of East Texas, southern Arkansas, western Louisiana, and southeastern Oklahoma. These coniferous forests are dominated by several species of pine as well as hardwoods including hickory and...
west of the Mississippi River
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
. They are now found in only four Louisiana parishes and five Texas counties. In Texas, records confirm their presence only in the southern portion of Sabine National Forest
Sabine National Forest
Sabine National Forest is located in East Texas near the Texas-Louisiana border. The forest is administered together with the other three United States National Forests and two National Grasslands located entirely in Texas, from common offices in Lufkin, Texas. The units include Angelina, Davy...
(Sabine County) and adjacent private land (Newton County
Newton County, Texas
Newton County is the easternmost county in the U.S. state of Texas. In of 2000, its population was 15,072. Its county seat is Newton. Newton county is named for John Newton, a veteran of the American Revolutionary War...
), and in the southern portion of Angelina National Forest
Angelina National Forest
Angelina National Forest is a United States National Forest, one of four located in Texas. The Angelina National Forest is located in East Texas in parts of San Augustine, Angelina, Jasper and Nacogdoches counties. It is managed together with the three other National Forests in Texas from...
(Angelina
Angelina County, Texas
Angelina County is a county located in the U.S. state of Texas. Angelina County was formed in 1846 from Nacogdoches County. As of 2000, the population was 80,130. Its county seat is Lufkin. Angelina is named for a Hainai Native American woman who assisted early Spanish missionaries and was named...
, Jasper, Tyler counties). Nearly all recent records are from two separate areas, each measuring less than 4 miles (6.4 km) in radius, and a third site (Scrappin' Valley) managed by Temple-Inland Corporation in northern Newton County. Most Louisiana records originate in Bienville Parish
Bienville Parish, Louisiana
Bienville Parish is a parish located in the northwestern portion of the U.S. state of Louisiana. The parish seat is Arcadia and as of the 2000 census, the population is 15,752....
on privately owned forestland. A second population occurs on federal lands in Vernon Parish
Vernon Parish, Louisiana
Vernon Parish is a parish located in the U.S. state of Louisiana. The parish seat is Leesville and as of 2000, the population was 52,531....
(Fort Polk
Fort Polk
Fort Polk is a United States Army installation located in Vernon Parish, approximately 7 miles east of Leesville, Louisiana and 20 miles north of DeRidder, Louisiana....
, U.S. Army, and Kisatchie National Forest
Kisatchie National Forest
Kisatchie National Forest, the only National forest in Louisiana, USA, is located in the state's old growth piney hills and hardwood bottoms of seven central and northern parishes. It totals more than of public lands....
). An apparently third population has been found near the juncture of Vernon, Sabine
Sabine Parish, Louisiana
Sabine Parish is a parish located in the U.S. state of Louisiana. The seat of the parish is Many. In 2010, the parish's population was 24,233....
and Natchitoches
Natchitoches Parish, Louisiana
Natchitoches Parish is a parish located in the U.S. state of Louisiana. The parish seat is Natchitoches. As of 2000, the population was 39,080. This is the heart of the Cane River Louisiana Creole community...
parishes.
Studies suggest that extensive population declines and local extinction
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
s of the Louisiana Pine Snake have occurred during the last 50-80 years. A habitat assessment of known historical localities found that only 34% were still considered capable of supporting a viable population of pine snakes. The species has not been documented in over a decade in some of the best remaining habitat within its historical range, suggesting extinction or extreme rarity. It is now recognized as one of the rarest snakes in North America, and one of the rarest vertebrate species in the United States.
Habitat loss
Urban development, conversion to agriculture, road construction, and mining have all contributed to loss and fragmentation of pine snake habitat. Direct human predation and collection for the pet trade may have also impacted populations. However, the greatest impact to Louisiana Pine Snakes has been loss of the native LongleafLongleaf Pine
Pinus palustris, commonly known as the Longleaf Pine, is a pine native to the southeastern United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida....
and Shortleaf Pine ecosystem. Virtually all timber in the South was cut during intensive commercial logging from 1870 to 1920. In 1935, only 3% of remaining Longleaf Pine forests in Louisiana and Texas existed as uncut, old-growth stands. In the 1980's, only 15% in Louisiana and 7% in Texas of the 1935 levels of natural Longleaf Pine forest still remained. The majority of this historic Longleaf and Shortleaf pine savanna forests has been replaced with plantations of fast-growing Loblolly
Loblolly Pine
Pinus taeda is one of several pines native to the Southeastern United States, from central Texas east to Florida, and north to Delaware. It is particularly dominant in the eastern half of North Carolina, where there are huge expanses consisting solely of Loblolly Pine trees...
and Slash Pine
Slash Pine
Pinus elliottii, commonly known as the Slash Pine, is a pine native to the southeastern United States, from southern South Carolina west to southeastern Louisiana, and south to the Florida Keys....
. These commercial plantations are typically grown in very dense, closed-canopy stands that are harvested on short rotations of less than 40 years. These forests have sparse and poorly structured understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
plant communities, rendering them uninhabitable for pocket gophers.
Fire suppression
Any remaining pine habitat occurs in isolated blocks and is often degraded by the lack of periodic wildfireWildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
s. The suppression of natural fire events may represent the greatest threat to the Louisiana Pine Snake in recent years, decreasing both the quantity and quality of habitat available to pine snakes. The Longleaf Pine savanna forest evolved as a fire climax
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
community, adapted to the occurrence of frequent, but low-intensity, ground fires. These natural fire events on sandy, well-drained soils typically maintained an overstory dominated by Longleaf Pine, with minimal midstory cover but a well-developed understory of native bunch grasses and herbaceous plants. These park-like forests supported ideal habitat for pocket gophers and, subsequently, pine snakes.
In the absence of periodic fires, these upland pine savanna ecosystems rapidly develop a dense mid-story which suppresses or eliminates any herbaceous understory. Since the presence of pocket gophers is directly related to the extent of herbaceous vegetation available to them, their population numbers and distribution declines as such vegetation declines. No pine snakes have been captured in areas substantially degraded by fire suppression. Observations indicate that pine snakes are well adapted to fire. Aboveground snakes quickly move into pocket gopher burrows as flames come near. Nine pine snakes residing in areas subjected to prescribed burns over three years time all survived with no damage.
Vehicle mortality
Louisiana Pine Snakes are also impacted by vehicle-caused mortality, both on state roads and on off-road trails. Researchers documented the loss of 3 snakes to vehicle traffic, including off-road vehicles. Further research indicated that roads with moderate to high traffic levels can reduce populations of large snakes by 50-75%, up to 2800 feet (853.4 m). Known conflicts between pine snakes and motorized vehicles exist in sections of the Longleaf Ridge Area of Angelina National ForestAngelina National Forest
Angelina National Forest is a United States National Forest, one of four located in Texas. The Angelina National Forest is located in East Texas in parts of San Augustine, Angelina, Jasper and Nacogdoches counties. It is managed together with the three other National Forests in Texas from...
. Motorized vehicles have eliminated a large part of the Millstead Branch bog community and the Catahoula Barrens community. In Sabine National Forest
Sabine National Forest
Sabine National Forest is located in East Texas near the Texas-Louisiana border. The forest is administered together with the other three United States National Forests and two National Grasslands located entirely in Texas, from common offices in Lufkin, Texas. The units include Angelina, Davy...
, vehicle conflicts occur on Foxhunter's Hill and the Stark Tract.
Recovery effort
Species with low reproductive rates, like the Louisiana Pine Snake, are typically incapable of quickly recovering from events that affect population size, increasing their potential for local extinctions. Survival of the Louisiana Pine Snake depends on that of Baird's Pocket GopherBaird's Pocket Gopher
Baird’s Pocket Gopher or Louisiana Pocket Gopher is a species of pocket gopher that is native to the Southern United States. In total, there are three almost identical species of eastern pocket gopher; Geomys attwateri, Geomys bursarius, and Geomys breviceps...
, whose abundance in turn depends on the understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...
plants and loose, sandy soil of the Longleaf Pine
Longleaf Pine
Pinus palustris, commonly known as the Longleaf Pine, is a pine native to the southeastern United States, found along the coastal plain from eastern Texas to southeast Virginia extending into northern and central Florida....
savannas. In March 2004, eight state and federal agencies signed a landmark Candidate Conservation Agreement to protect the Louisiana Pine Snake on federal lands in Texas and Louisiana. Organizations participating in the effort include: Fort Polk Military Installation, Kisatchie National Forest
Kisatchie National Forest
Kisatchie National Forest, the only National forest in Louisiana, USA, is located in the state's old growth piney hills and hardwood bottoms of seven central and northern parishes. It totals more than of public lands....
, National Forests in Texas, Louisiana Department of Wildlife and Fisheries, Texas Parks and Wildlife Department
Texas Parks and Wildlife Department
The Texas Parks & Wildlife Department is a Texas state agency that oversees and protects wildlife and their habitats. In addition, the agency is responsible for managing the state's parks and historical areas...
, United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
's Southeast and Southwest Regions, and United States Forest Service
United States Forest Service
The United States Forest Service is an agency of the United States Department of Agriculture that administers the nation's 155 national forests and 20 national grasslands, which encompass...
's Southern Research Station. The voluntary agreement provides a way for the agencies to collaborate on projects to avoid and minimize impacts to the snake. The agreement also sets up a mechanism to exchange information on successful management practices and to coordinate research efforts. Fire is central to the recovery effort. Without fire, these upland pine savanna ecosystems rapidly develop a mid-story that excludes the herbaceous understory needed by pocket gophers. When gopher populations decline, so do those of the pine snake.
The management actions proposed by the partners in the agreement are designed to restore and protect the remaining Longleaf Pine forests of east Texas and western Louisiana. Frequent, low-intensity ground fires are required to maintain the open midstory of these forests; many of the plants must literally be burnt to reproduce or grow. Longleaf Pine forests are very special habitats, being among the most biologically diverse ecosystems outside the tropics. Over 30 plant and animal species associated with Longleaf Pine ecosystems are endangered or species of concern.
The American Zoo and Aquarium Association manages a Species Survival Plan
Species Survival Plan
The American Species Survival Plan or SSP program was developed in 1981 by the Association of Zoos and Aquariums to help ensure the survival of selected species in zoos and aquariums, most of which are threatened or endangered in the wild....
for the Louisiana Pine Snake, headquartered at the Memphis Zoo
Memphis Zoo
The Memphis Zoo, located in Midtown Memphis, Tennessee, is home to more than 3,500 animals representing over 500 different species. Created in April 1906, the zoo has been a major tenant of Overton Park for more than 100 years. The land currently designated to the Memphis Zoo was defined by the...
. The Species Survival Plan insures that the precious captive population maintained in zoos, which sits precariously at less than 100 individuals, is managed wisely and for the long term.
Sources
[NOTE: Unless otherwise stated, the principal source of material presented here was: U.S. Fish and Wildlife Service: Louisiana pine snake (cited above). That work was summarized from an extensive literature review presented in: Candidate Conservation Agreement for the Louisiana Pine Snake (cited above). Users desiring more detailed, referenced material should consult the literature review.]