Occurrence in North America
through Florida and west to Louisiana, Mississippi, and Alabama. The
Texas indigo snake is found in southern Texas and Mexico .
Distribution: USA (S Texas, Florida, SE Georgia, S Alabama), Mexico (Yucatan, Aguascalientes, Tamaulipas), Guatemala, Honduras (Islas de la Bahia, Isla de Utila: [HR 31: 255]), Belize, El Salvador, Nicaragua, Panama, Trinidad, Tobago, French Guiana, Colombia, Venezuela (Mérida), Brazil (Amapá, Rondonia, Roraima, Goias), Ecuador, Peru, Bolivia, N Argentina (Chaco, Formosa), Paraguay (LEYNAUD & BUCHER 1999) elevation; 0-1555 m (Honduras) margaritae: W Margarita Islands, Venezuela;
Type locality: Near San Francisco de Macanao, Isla Margarita, Venezuela. melanurus: Mexico rubidus: Mexico (Michoacan, Sinaloa);
Type locality: Rosario,Sinaloa.
Type locality: America [corais]
Type locality: San Francisco de Macanao, Isla de Margarita, Venezuela [margaritae]
Type locality: Mexico [melanurus]
Belizean Pine Forests Habitat
This species is found in the Belizean pine forests along the Central America's northwestern Caribbean Sea coast; the ecoregion exhibits relatively well preserved fragments of vegetation as well as a considerable abundance of fauna. This ecoregion comprises a geographically small portion of the total land area of the ecoregions of Belize. There is relatively low endemism in the Belizean pine forests, and only a moderate species richness here; for example, only 447 vertebrate taxa have been recorded in the ecoregion. The ecoregion represents one of the few examples of lowland and premontane pine forests in the Neotropics, where the dominant tree species is Honduran Pine (Pinus caribaea var. hondurensis), which requires periodic low intensity burns for its regeneration. The vegetation is adapted to the xeric, acidic and nutrient-poor conditions that occur primarily in the dry season.
In the forest of the Maya Mountains, vegetation reaches higher altitudes, the topography is more rugged and crossed by various rivers, and nighttime temperatures are lower. The pine trees are larger and numerous, and the pine forest intersects other formations of interest such as rainforest, Cohune Palm (corozal), cactus associations, and others. About eleven percent of Belize is covered by natural pine vegetation. Only two percent represents totally closed forests; three percent semi-closed forests; and the remaining six percent pine savannas, that occupy coastal areas and contain isolated pine trees or stands of pine trees separated by extensive pastures. In addition to human activity, edaphic factors are a determining matter in this distribution, since the forests on the northern plain and southern coastal zone are on sandy soils or sandy-clay soils and usually have less drainage than the more fertile soils in the center of the country.
At elevations of 650 to 700 metres, the forests transition to premontane in terms of vegetation. At these higher levels, representative tree species are Egg-cone Pine (Pinus oocarpa), which crosses with Honduras Pine (P. hondurensis), where distributions overlap, although belonging to subsections of different genera; British Honduras Yellowwood (Podocarpus guatemalensis) and Quercus spp.; moreover, and in even more moist areas there is a predominance of Jelecote Pine (Pinus patula), together with the palm Euterpe precatoria var. longivaginata and the arboreal ferns Cyathea myosuroides and Hemitelia multiflora.
A number of reptilian species are found in the Belizean pine forests, including: Guatemala Neckband Snake (Scaphiodontophis annulatus); Indigo Snake (Drymarchon corais); On the coasts, interior lakes and rivers of Belize and by extension in this ecoregion there are two species of threatened crocodiles: American Crocodile (Crocodylus acutus) and Morelet's Crocodile (C. moreletii), while observation of the Central American River Turtle (Dermatemys mawii CR) is not uncommon in this ecoregion.
Also to be noted is the use of this habitat by the Mexican Black Howler (Alouatta pigra), which can be considered the most endangered howler monkey of the genus, and the Central American spider monkey (Atteles geoffroyi). Both species experienced a decline due to the epidemic yellow fever that swept the country in the 1950s. The five feline species that exist in Belize: Jaguar (Panthera onca), Puma (F. concolor), Ocelot (Leopardus pardalis), Margay (Leopardus wiedii) and Jaguarundí (Herpailurus yagouaroundi) are in appendix I of CITES, as well as the Central American tapir (Tapirus bairdii) can been seen with relative frequency. Belize has the highest density of felines in Central America. The tapir is abundant around rivers. The White-lipped Peccary (Tayassu pecari) is also present in the ecoregion.
Although most of the amphibians and reptiles are found in humid premontane and lowland forests, the only endemic frog in this ecoregion, Maya Mountains Frog (Lithobates juliani), is restricted to the Mountain Pine Ridge in the Maya Mountains. Salamanders in the ecoregion are represented by the Alta Verapaz Salamander (Bolitoglossa dofleini NT), whose males are arboreal, while females live under logs. Anuran taxa found in the ecoregion include: Rio Grande Frog (Lithobates berlandieri); Sabinal Frog (Leptodactylus melanonotus); Northern Sheep Frog (Hypopachus variolosus); Stauffer's Long-nosed Treefrog (Scinax staufferi); and Tungara Treefrog (Engystomops pustulosus).
Present in the ecoregion are a number of avian species, including the endangered Yellow-headed Amazon Parrot (Amazona oratrix EN), although this bird is adversely affected by ongoing habitat destruction. Of particular interest is the presence in this ecoregion of Central America's highest procreative colony of Jabiru (Jabiru mycteria), a large migratory bird, particularly in the Crooked Tree sanctuary, on the country's northern plains.
Associated Plant Communities
Florida and Georgia. These communities are primarily scrub oak-longleaf
pine (Pinus palustris) with occasional live oak (Quercus virgianiana),
laurel oak (Q. laurifolia), Chapman's oak (Q. chapmanii), and myrtle oak
(Q. myrtifolia). Other communities include longleaf pine-turkey oak (Q.
laevis), slash pine (Pinus elliottii)-scrub oak, pine flatwoods, and
pine-mesic hardwoods .
This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):
FRES12 Longleaf-slash pine
FRES13 Loblolly-shortleaf pine
FRES32 Texas savanna
Because the cover requirements of indigo snakes change seasonally,
maintaining corridors that link the different habitats used is
important. From the spring through fall snakes must be able to travel
from sandhill communities and upland pine-hardwood communities to creek
bottoms and agricultural fields . In winter indigo snakes den in
gopher tortoise burrows, which are usually found in open pine forests
with dense herbaceous understories . Burrows need to be in areas
where there is no flooding. Indigo snakes also heavily use debris piles
left from site-preparation operations on tree plantations . These
piles are often destroyed for cosmetic reasons but should be left intact
because they provide important hiding cover for both the snake and its
prey. Summer home ranges for the indigo snake can be as large as 273
acres (229 ha) .
Indigo snakes frequent flatwoods, hammocks, dry glades, stream bottoms,
cane fields, riparian thickets, and high ground with well-drained, sandy
soils . In Georgia, snakes prefer excessively drained, deep sandy
soils along major streams, as well as xeric sandridge habitats .
Xeric slash pine plantations seem to be preferred over undisturbed
longleaf pine habitats . Habitat selection varies seasonally. From
December to April indigo snakes prefer sandhill habitats; from May to
July snakes shift from winter dens to summer territories; from August
through November they are located more frequently in shady creek bottoms
than during other seasons .
Habitat: Cover Types
This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):
More info for the terms: hardwood, swamp
66 Ashe juniper - redberry (Pinchot) juniper
70 Longleaf pine
71 Longleaf pine - scrub oak
72 Southern scrub oak
81 Loblolly pine
82 Loblolly pine - hardwood
84 Slash pine
85 Slash pine - hardwood
89 Live oak
104 Sweetbay - swamp tupelo - redbay
105 Tropical hardwoods
111 South Florida slash pine
241 Western live oak
Habitat: Plant Associations
This species is known to occur in association with the following plant community types (as classified by Küchler 1964):
K061 Mesquite - acacia savanna
K062 Mesquite - live oak savanna
K078 Southern cordgrass prairie
K079 Palmetto prairie
K080 Marl - everglades
K091 Cypress savanna
K112 Southern mixed forest
K113 Southern floodplain forest
K115 Sand pine scrub
K116 Subtropical pine forest
variety of small birds and mammals, and eggs [6,11].
fatalities, wanton killings, and overcollection for the pet trade
adversely affect indigo snake populations. Snakes are taken illegally
from the wild and sold as pets for as much as $250 each. Snakes are
also inadvertantly gassed in their burrows by rattlesnake hunters .
Habitat-related Fire Effects
Fire exclusion in southern pine-scrub oak habitats is a major cause of
habitat degredation for gopher tortoise and, therefore, indigo snakes
. The absence of fire allows oaks to mature and leaf litter to
accumulate, making burrow digging difficult and herbaceous food scarce.
Studies of herpetofauna in Florida sandhill commmunities showed higher
species diversity in young sand pine (Pinus clausa)-scrub oak habitats,
which are maintained by frequent fire . Experimental burns in these
communities showed snakes used plots burned at 2- and 7-year intervals
more than plots left unburned or burned yearly. The effects of
different season burns on gopher tortoises in Ocala National Forest,
Florida, showed more burrows in July-burned areas than in
February-burned areas at the first postfire year . Preburn densities
of gopher tortoise were not determined.
Timing of Major Life History Events
November through March with a peak in mid-November through late
December. The age of sexual maturity is unknown . An average of 3
to 10 eggs are laid in March through July; eggs hatch from May through
October . The average life span of the indigo snake is 11 years,
although they can live as long as 21 years . They do not hibernate
and remain somewhat active during winter, especially if temperatures are
higher than 50 degrees Fahrenheit (10 deg C) .
Life History and Behavior
Lifespan, longevity, and ageing
Molecular Biology and Genetics
Statistics of barcoding coverage: Drymarchon corais
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
U.S. Federal Legal Status
as Threatened .
Georgia, Florida, Alabama, and South Carolina . The state of Florida
lists it as threatened .
Use of Fire in Population Management
Landers and Speake  recommend burning indigo snake habitats every 2
years to maintain a young, open overstory and an abundant herbaceous
understory. This will provide good gopher tortoise habitat, which in
turn will provide burrows for snakes. Burning sandhill communities
every 2 to 4 years will maintain open longleaf pine stands with
understories of wiregrass (Aristida stricta) and turkey oak .
Burning in late summer where young indigo snakes have been released from
captive breeding programs is not recommended because young snakes depend
on dense herbaceous vegetation for cover instead of burrows .
Indigo snakes are a commensal species associated with gopher tortoises.
Snakes use abandoned tortoise burrows heavily in the winter and spring
. For this reason it is necessary to maintain healthy tortoise
populations, also a species in decline throughout its range. Because
slash piles are used by snakes for hiding and foraging, this debris
should be left intact on pine plantations . Speake and others 
recommend protecting several thousand hectares of prime indigo snake
habitat to ensure the snakes' year-round needs are met. Some important
sandhill communities of Georgia and Florida are being replaced by slash
pine plantations, which can support a few snakes if burned and planted
with wide spacing to encourage gopher tortoise populations .
Recommendations for captive breeding of indigo snakes are as follows
: Captive snakes should be released to the wild after 2 to 3 years,
and new snakes from the wild should be introduced to the captive
population, preferably every winter. This is important because wild
snakes seem to grow faster and produce more young than snakes held in
captivity. Because smaller snakes do not use tortoise burrows, they
should be released in wetland areas with plenty of herbaceous cover near
the water's edge. Hatchlings will den in areas with dense saw palmetto
(Serenoa repens) and should be released near these areas.
Names and Taxonomy
American corais snake
blue bull snake
blue gopher snake
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