Eastern Indigo Snake

(Drymarchon corais)

*Species description adapted from Snyder, 1993.

LEGAL STATUS:

The eastern indigo snake (Drymarchon corais couperi) is federally listed as Threatened [1].  The state of Florida also lists it as Threatened [2].

TIMING OF MAJOR LIFE HISTORY EVENTS:

Indigo snakes can grow as long as 125 inches (262 cm).  They mate from November through March with a peak in mid-November through late December.  The age of sexual maturity is unknown [3].  An average of 3 to 10 eggs are laid in March through July; eggs hatch from May through October [4].  The average life span of the indigo snake is 11 years, although they can live as long as 21 years [5].  They do not hibernate and remain somewhat active during winter, especially if temperatures are higher than 50 degrees Fahrenheit (10 deg C) [3].

PREFERRED HABITAT:

Indigo snakes frequent flatwoods, hammocks, dry glades, stream bottoms, cane fields, riparian thickets, and high ground with well-drained, sandy soils [5].  Xeric slash pine plantations seem to be preferred over undisturbed longleaf pine habitats [6].  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 [3].

COVER REQUIREMENTS:

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 [3].  In winter indigo snakes den in gopher tortoise burrows, which are usually found in open pine forests with dense herbaceous understories [6].  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 (110 ha) [3].

MANAGEMENT CONSIDERATIONS:

Indigo snakes are a commensal species associated with gopher tortoises.  Snakes use abandoned tortoise burrows heavily in the winter and spring [7].  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 [6].  Speake and others [3] 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