Leptodeira septentrionalis

Geographic Range

Leptodeira septentrionalis can be found in North and South America. The northern range boundary of Leptodeira septentrionalis can be found in the southern tip of Texas. Their populations run throughout central America to western Venezuela and northwestern Peru in South America.

• Biogeographic Regions
• nearctic nearctic
  • native native
• neotropical neotropical
  • native native

Habitat

Leptodeira septentrionalis can be found in a multitude of environments ranging from semi-arid scrub to rain forests. Within it's Texan range, Leptodeira septentrionalis prefers semi-arid, thorn brush habitats with ponds or streams in which to hunt breeding amphibians and their eggs. In Mexico, these snakes have been documented at elevations of up to 1,981 m.

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• rainforest rainforest
• scrub forest scrub forest

• Aquatic Biomes
• lakes and ponds
• rivers and streams
• temporary pools

Physical Description

Leptodeira septentrionalis is characterized by a head that is much wider than its neck and large eyes with vertical pupils that give the common name, cat-eyed snakes. Above, these snakes are tan, buff, pale gold, or pale orange yellow with a distinctive pattern of large to medium-sized, brown, dorsal blotches or "saddles". Body coloration and size of dorsal spots may vary geographically. The crown is dark with a "spearhead" pointed towards the rear. They feature a thin, dark line on the posterior of each eye. The ventral surface is pale orange anteriorly but becomes brighter closer to the tail. Each ventral scale has a dark border. Adults weigh an average 29.1 g and have an average length of 45.7 to 61 cm. There is little sexual dimorphism in this species, but females average slightly longer than males.

Young cat-eyed snakes resemble adults, but have much stronger coloration. Hatchlings measure 22.9 cm in length.

Leptodeira septentrionalis belongs to a special class of snake known as Opisthoglyphous , or rear fanged snakes. The fangs of these snakes are located at the back of the jaw, so the snake has to position its prey in its jaw in order to bite it. The venom of cat-eyed snakes is of relatively low toxicity and is only enough to subdue small prey.

There are several species that may be confused with northern cat-eyed snakes. The brown-banded morphs of ground snakes have thinner heads, a less contrasting pattern, and round pupils. Differences in coloration distinguish southwestern rat snakes which have dark blotches covering the first half of their bodies, and Texas night snakes which have small dorsal spots bordered by a lateral row of smaller spots.

• Other Physical Features
• heterothermic heterothermic
• venomous venomous

• Sexual Dimorphism
• female larger

Development

Leptodeira septentrionalis are oviparous and lay 6 to 12 eggs per clutch. Developing snakes are nourished by a yolk sac for 79 to 90 days at which time they hatch using an egg tooth to break through the outer shell. The egg tooth is lost after hatching. Young northern cat-eyed snakes appear identical to adults but feature much fresher coloration. The snakes will continue to grow throughout their entire lives.

• Development - Life Cycle
• indeterminate growth indeterminate growth

Reproduction

Little has been studied regarding the mating habits of Leptodeira septentrionalis .

Leptodeira septentrionalis breeds once a year in early spring. Gravid females have been observed from February 11 through May 14. Females lay between 6 and 12 eggs per clutch and the gestation period lasts between 79 to 90 days. The young are 22.9 cm upon hatching. Reproductive age for this species is currently unknown.

Delayed fertilization has been reported in this species. After being captured in the wild, a female laid a clutch of fertile eggs each of the three years kept in captivity. During its time in captivity, this female never came into contact with a male and so must have used sperm from its last mating activity three years earlier.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• sexual sexual
• fertilization fertilization
• oviparous oviparous
• delayed fertilization delayed fertilization

Little has been studied regarding the parental investment of Leptodeira septentrionalis . In general, parental care is not well developed in snakes.

Lifespan/Longevity

Lifespan of Leptodeira septentrionalis is unknown.

Behavior

Northern cat-eyed snakes are strictly nocturnal. During the hours of the day, they hide under logs, leaf litter or other vegetative debris. While not being able to climb trees, its long slender body allows it to reach low branches in search of sleeping prey. These snakes are solitary and presumably only come together to mate. They have not been observed defending territories and seem to be a nomadic species.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• nomadic nomadic
• solitary solitary

Home Range

Leptodeira septentrionalis is not a territorial animal and home ranges have not been documented.

Communication and Perception

Leptodeira septentrionalis uses the vomeronasal system to sense the world around it. The vomeronasal system involves the tongue and the Jacobson's organ. Northern cat-eyed snakes will flick its tongue in the air to gather tiny particles which it will rub against the roof of its mouth where the Jacobson's organ is located. The Jacobson's organ is a chemoreceptor that can detect prey as well as pheremones from other snakes.

When threatened, Leptodeira septentrionalis will coil its body and flatten its head in order to intimidate the approaching creature. It may strike the air several times in a threatening manner, but this species will rarely actually bite.

Little is known regarding the reproductive behaviors and associated communications for this species. The presence of chemoreceptors suggests that pheromones play a role in finding or securing a mate.

Like many snakes, northern cat-eyed snakes do not rely heavily on visual stimuli to perceive their environments. In general, snake eyes are more primitive and have limited focusing ability and have trouble perceiving stationary objects. Snakes also feature minimal ear structures and likely lack the ability to hear. Therefor, the hissing and rattling that some snakes emit is meant to deter predators as opposed to communicate intraspecifically. The ear structures they do have are situated near the ground which greatly enhances their ability to perceive vibrations.

• Communication Channels
• visual visual
• chemical chemical

• Other Communication Modes
• pheromones pheromones

• Perception Channels
• visual visual
• tactile tactile
• vibrations vibrations
• chemical chemical

Food Habits

The primary diets of northern cat-eyed snakes consist of frogs however, it will also consume lizards, toads, salamanders, tadpoles, small fish and mice. If the prey is small enough, the snake will swallow it whole while it is still alive. If it is a larger animal, the snake will position it to the back its jaw and will use its rear fangs to puncture the prey many times so the low-toxicity venom will seep into the wounds and eventually paralyze the prey. These snakes are often found hunting near ponds and rivers with abundant breeding amphibians. Snakes will drill their heads into the egg sack and eat the eggs one at a time.

The diet of northern cat-eyed snakes changes with the seasons. During the dry season, these snakes will start feeding primarily on lizards which remain active throughout the arid conditions. They may also hunt in small puddles where fish and frogs are trapped. Frog mating season often coincides with the rainy season, at which time snakes consume mostly amphibians and their eggs.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates

• Animal Foods
• mammals
• amphibians
• reptiles
• fish
• eggs

Predation

When threatened, some individuals may strike the air several times in an effort to ward off the predator, but they will rarely actually bite. The primary method of predator avoidance is to run and hide. If it is cornered, it will become tightly coiled and flattened its head to look more intimidating. In order avoid visual-detecting predators, Leptodeira septentrionalis has coloration that is well camouflaged with its environment. A nocturnal lifestyle also helps to avoid being detected while active. Several documented predators include crane hawks , white hawks , collared forest-falcons , roadside hawks , and great black hawks .

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

As a predator and prey, Leptodeira septentrionalis impacts many local populations. They are also hosts for many parasites including nematodes of the genus Kalicephalus .

Economic Importance for Humans: Positive

Leptodeira septentrionalis has no positive affects on humans.

Economic Importance for Humans: Negative

While Leptodeira septentrionalis is venomous, the poison is not harmful to humans. A zookeeper that was bitten by one of these snakes received symptoms no worse than a bee sting. Leptodeira septentrionalis has also been known to stow away in crates containing food or other items, but they cause virtually no damage.

• Negative Impacts
• injures humans
  • venomous venomous

Conservation Status

Leptodeira septentrionalis is considered threatened in the state of Texas. It inhabits ponds and streams in the Rio Grand Valley, however, the urbanization of this area has caused the habitat of northern cat-eyed snakes to shrink and is threatening to push the species out of Texas. Emphasis on habitat protection or restoration is necessary to ensure the presence of northern cat-eyed snakes in their native, Texan range. Little is known regarding threats to this species in its tropical range, but habitat destruction through deforestation, urbanization, agricultural clearing, and pollution threaten most ecosystems of the region.

Additional Links

Encyclopedia of Life

Contributors

Bruce Gentry (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.

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