Naja pallidaAfrican Cobra, Red Spitting Cobra

Geographic Range

Red spitting cobras (Naja pallida) are native to Africa. They are located in most of eastern Africa. They range from Egypt to northern Tanzania, including areas from eastern parts of Uganda and Sudan to the coasts of Somalia and Kenya. The largest populations of this species inhabit Ethiopia, Somalia, Kenya, Uganda, and Tanzania. (Wuster and Broadley, 2003; Wuster and Broadley, 2007)

Habitat

Being concentrated in eastern Africa, Naja pallida is situated in a diverse region, including temperate and tropical areas. Exact elevations are unclear but they range form about 40 m above sea level in the lowlands of Somalia to about 1,995 m in the highlands of Kenya. These areas include semiarid lands, wetlands, and similar biomes. Annual temperatures average 18°C in highlands and 26.5°C in lowlands. Naja pallida is present in the areas described above, but is most common in the drier, warmer lowlands such as savannas and semi-deserts. (Mailafiya, et al., 2009; Wuster and Broadley, 2003; Wuster and Broadley, 2007)

  • Range elevation
    40 to 1,995 m
    131.23 to ft
  • Average elevation
    1,000 m
    ft

Physical Description

Naja pallida is commonly known as the red spitting cobra because of its common brick-red or red-orange color; it may also be brown, pink, yellow or grey. Red spitting cobras are distinguished from other snakes within the genus Naja by the single, thick dark band around their necks and throats. Red spitting cobras are also distinct in that they have 11 to 15 small temporal and nuchal scales around their parietals (part of their heads). Red spitting cobras also have distinct darkened scales along the rest of their bodies. Red spitting cobras have completely black eyes.

Red spitting cobras are considered to be small to medium-sized cobras, with an average adult size of 70 to 150 cm snout-vent length (SVL). The largest recorded specimen of this species had an SVL of 190 cm. Males and females are alike in body size. Juvenile red spitting cobras have an average SVL of 30 to 50 cm. There is no available data for average weights of red spitting cobras. Red spitting cobras, like many other closely-related snakes, have distinctive hoods. These hoods are thought to be used to aid in locomotion and the generation of force when striking or, in this case, spitting.

Red spitting cobras are ectothermic (cold-blooded) animals with no internal methods for heat regulation so warm environments are most suitable for them. Red spitting cobras can survive with body temperatures from 0 to 40 °C; anything outside of this range is considered life threatening.

Red spitting cobras are like most elapids in that they have hollow fangs to inject their venom. Red spitting cobras have four fixed venomous fangs. Fang lengths for this species are about 4.5 mm long with a width of 1 mm at the base. The fangs of cobras are generally smaller and more numerous than other snake groups, such as vipers. Because the teeth of cobras are so small and brittle (especially fangs due to the hollow venom canals), snakes regularly regrow their broken or lost teeth. The fangs of red spitting cobras have wider, less elongated venom canal openings, which do not extend all the way to the fang points. The openings are located at the fronts of the fangs in spitting cobras. The fangs of red spitting cobras have internal ridges, which are believed to reduce loss of pressure and velocity when these snakes spit venom. Their fangs lack a groove that helps push venom downward. Because there is no groove to guide venom downward, the stream of venom exits horizontally outward from the front of the fang, rather than downward at the bottom of the fang. Exit orifices in these fangs are angled at the end of the venom canals to direct the spray outward at predators or prey.

The fangs of red spitting cobras are specifically designed to penetrate the flesh and keep hold of prey. Because their teeth are sharp and narrow, red spitting cobras do not chew on captured food. Like other snakes, they are able to unhinge their lower jaws and swallow prey whole. This is made possible by flexible bones and segmented palatomaxillary arches and mandibles. The segments of the jaw can be moved independently, allowing red spitting cobras to manipulate their jaws around their prey. Red spitting cobras lack facial pits that allow other snake species to sense infrared, which aids in nocturnal hunting. Because they lack these pits, red spitting cobras have adapted to be diurnal predators.

Red spitting cobras have distinctive scale counts compared to similar species in the genus Naja. Ventral scale counts range from 192 to 227 and subcaudal counts (the ventral scales from their anal scales down) range from 56 to 81 scales. Red spitting cobras have 1 or 2 darkened preocular scales (scales on the front side of the bottom of the eye), paired with 6 to 7 supralabial scales. Dorsal counts range from 21 to 29 scales around their necks, 21 to 27 scales around their midbodies, and 17 to 19 scales in a single row from their heads to their vents. Red spitting cobras have a single anal scale. (Berthé, 2011; Cascardi, et al., 1999; "Guidelines for the Prevention and Clinical Management of Snakebite in Africa", 2010; Largen and Rasmussen, 1992; Novak, et al., 1987; Phelps, 1981; Westhof, et al., 2005; Wuster and Broadley, 2003; Wuster and Broadley, 2007; Wuster and Thorpe, 1992; Young, et al., 2009; Young, et al., 2004)

  • Sexual Dimorphism
  • sexes alike
  • Range length
    70 to 190 cm
    27.56 to 74.80 in
  • Average length
    120 cm
    47.24 in

Development

Ages for wild red spitting cobras is determined through histological examination of their bones. Their bones show periods of growth through rings, similar to tree rings. These snakes forego most growing during winter, since most of their energy is used for hibernation. If bone examination is not an option, mark-recapture efforts assist in age estimations.

The time from hatching to sexual maturity takes around 3 years. Hatchlings have an average snout-vent length (SVL) of 31.7 cm and grow to sizes of 70 to 150 cm when mature. Juveniles are born with a complete set of teeth, including fangs. Juveniles have fully functioning venom glands and receive no instruction on how to hunt. Though red spitting cobras reach sexual maturity at 3 years, they continue to grow until around 9 years of age. Red spitting cobras maintain a uniform body ratio throughout development, and are the same color and shape from birth to death. (Chiszar, et al., 1982; Mullin and Seigel, 2009; Novak, et al., 1987; Phelps, 1981)

Reproduction

Red spitting cobras are oviparous, meaning they lay eggs that then hatch into juveniles. Their mating season is from mid-spring through early summer. This is correlated with temperature and hibernation periods. Red spitting cobras are solitary and do not have the same mate every mating cycle. Females actively choose a male, after which the two will perform courtship behaviors. Courtship behavior involves a male and females tangling their bodies together. Intercourse may last hours to days in order to fertilize eggs. (Novak, et al., 1987)

For red spitting cobras to engage in courtship behaviors, males and females must be close enough to each other to sense lipoprotein vitelligenin pheromones that these snakes release. Usually males will sense pheromones released by females and follow these pheromone trails to their source. Males use their noses and tongues to sense and follow these pheromones. Occasionally, red spitting cobras will detect pheromones from other species or from the same sex. Once red spitting cobras find a viable mate, males will perform dances. Males raise and lower their heads, sway their heads side-to-side, flick their tongues, and give chase to females.

Red spitting cobras reach sexual maturity after 2 to 3 years. Reproductive behavior in temperate-zone male snakes is called "dissociated" (Crews, 1984). This means there is a difference in seasons between the peak of spermatogenic activity and reproductive behavior. Male snakes have two cycles for reproductive behavior: postnuptial and prenuptial. Red spitting cobras mainly experience postnuptial reproductive cycles. In postnuptial behavior, spermatogenesis rises in male snakes in the late months of spring, directly after mating. It declines in the fall. This may suggest two breeding seasons, though no such information has been found.

Females have reproductive behavior that is more uniform than males. Female produce oocytes at the same time as vitellogenesis takes place. The production of oocytes and vitellogenesis occurs in spring. This process is triggered by the act of mating. Development time from oocyte to ova is about 3 years in cobras. During ovulation, females seek warmer areas and bask in the sun. Female cobras experience seasonal reproduction, commonly associated with a period of about 3 to 6 months during the rainy season. Female red spitting cobras have clutch sizes of 2 to 16 eggs, while the average clutch size is about 7 eggs. It is uncommon for females to protect their eggs after laying them, or after they hatch. (Novak, et al., 1987; Mullin and Seigel, 2009; Novak, et al., 1987)

  • Breeding interval
    Red spitting cobras breed once yearly
  • Breeding season
    Spring to early Summer; Warm, wet months
  • Range number of offspring
    2 to 16
  • Average number of offspring
    7
  • Range gestation period
    80 to 120 days
  • Average gestation period
    112 days
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 32 years

Red spitting cobras are solitary. It has been rare to find a female protecting its eggs, and when the female is guarding its eggs they are usually freshly laid. There is no parental investment by males or females during incubation. (Novak, et al., 1987)

  • Parental Investment
  • no parental involvement
  • precocial

Lifespan/Longevity

Maximum longevity for captive red spitting cobras is reported at 20.2 years. No reports of longevity in the wild have been published. (Snider and Bowler, 1992)

  • Range lifespan
    Status: captivity
    20.2 (high) years

Behavior

Red spitting cobras are solitary; adults are nocturnal while juveniles are diurnal. The only social behaviors they exhibit are territorial disputes, courtship, and mating. During territorial disputes and while hunting red spitting cobras display elevated rates of tongue flicking. When these snakes are aggravated they will engage each other, or their prey, and will sway their heads back and forth. In territorial disputes this head swaying tactic is used to intimidate enemies. If neither of the males involved are intimidated, they lock necks in an attempt to pin each other to the ground. Biting during territorial disputes is rarely observed and has no apparent effect on bitten males.

Red spitting cobras do not have any fixed territory. Instead they will defend whatever area they are in at the time. Males have disputes over mates as well as territory. These two kids of disputes look much the same

A behavior uniques to the genus Naja is the ability to "spit" venom. Naja species eject venom from their hollow fangs to try and blind prey or predators. Red spitting cobras are known for having an accurate, fine spray. They can spit venom up to 2.5 meters away and 40 times in 2 minutes. They use this adaption when engaging prey and predators. Males do not use this adaptation in disputes with other males. (Boyer, et al., 1986; Chiszar, et al., 1982; Krimm, et al., 2009; Mullin and Seigel, 2009; Novak, et al., 1987; Parker, 1963)

Home Range

Red spitting cobras do not defend a fixed territory. Home ranges have not been reported for this species. In other cobras, home ranges of 6.3 square km have been reported. It's likely that home ranges for red spitting cobras are similar. (Stuart, et al., 2012)

Communication and Perception

Red spitting cobras rely mostly on visual stimuli and, secondarily, chemosensory perception and thermal senses. Snakes cannot hear well, but they do pick up vibrations from the ground through their jaws. These snakes are solitary animals, only interacting for courtship. It is expected that they communicate and dispute over food or territory, though no such aggression has been reported.

For these snakes to engage in courtship behaviors, an individual must be close enough to a potential mate to sense their pheromones. To communicate with females, males perform dances. This involves raising and lowering their heads, swaying their heads from side to side, and flicking their tongues. If an individual female accepts a male as a mate, it will turn away and the male will give chase.

In disputes, red spitting cobras only engage through vomeronasal and chemosensory cues. If either of these senses are blocked, no contact will occur. To establish dominance, competing snakes raise their bodies, sway their heads, and attempt to hook necks in order to wrestle their opponent to the ground.

When hunting, red spitting cobras use mainly visual and vomeronasal cues to locate prey. They are able to differentiate the scent marks of different animals and recognize specific chemical cues from their prey. Snakes use the forked tips of their tongues to pick up chemicals from the environment. Once snakes retract their tongues, the forked tips enter two separate internal nasal cavities, called the vomeronasal organ. The vomeronasal organ then sends information about chemicals to the brain. (Boyer, et al., 1986; Chiszar, et al., 1982; Krimm, et al., 2009; Mullin and Seigel, 2009; Novak, et al., 1987; Parker, 1963; "Poisonous Snakes of the World", 1962)

Food Habits

Red spitting cobras are strictly carnivorous, normally only taking prey that they have killed themselves. Their primary diet consists of rodents, lizards, and frogs or toads. Juvenile red spitting cobras select prey based on their familiarity of prey in the area, prey abundance, and their ability to safely kill the animal. Red spitting cobras are active foragers, looking for food rather than waiting for prey and ambushing them. They are also considered active hunters because, once they spot prey, they will chase that prey.

Red spitting cobras, like most elapid cobras, primarily use visual stimuli to spot prey. If prey is close by but out of sight, red spitting cobras can sense that prey is close by using thermal and chemical cues. They pick up chemical traces by flicking their tongues. Red spitting cobras must be close to their prey to detect them using chemical and thermal cues. Therefore, detecting prey using visual cues is a more efficient technique. Before striking at prey, red spitting cobras will display erratic, frantic movements to confuse and hopefully immobilize prey. Pre-striking behavior may also include the spitting of a venomous stream to try and blind prey. Red spitting cobras have an accurate stream that they can use effectively on targets up to 2.5 m away. The average range of striking distance is around 4.5 cm. Red spitting cobras strike and hold onto their prey until it is dead. However, if a prey item escapes, red spitting cobras can follow them using chemosensory cues from the injected venom. After red spitting cobras catch a prey item, they consume it whole (Chiszar, et al., 1982; Berthé, 2011; Boyer, et al., 1986; Chiszar, et al., 1982; Kardong, et al., 1997; Novak, et al., 1987)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • mammals
  • amphibians
  • reptiles

Predation

Red spitting cobras have no true predators. The only dangers to them are injuries from intraspecific competition, being crushed by large animals or objects, parasites, and hunting by humans (Homo sapiens). Red spitting cobras may exhibit elevated rates of tongue flicking and hissing when threatened. (Boyer, et al., 1986; Chiszar, et al., 1982; Krimm, et al., 2009; Mullin and Seigel, 2009; Novak, et al., 1987; Seigel and Collins, 1993)

Ecosystem Roles

Red spitting cobras, like many snakes, is a top predator in their wild habitats. Red spitting cobras consume rodents, birds, lizards, and amphibians.

Apicomplexans (Caryospora najae) are a known parasite of this species. (Matuschka, 1982; Mullin and Seigel, 2009; Novak, et al., 1987; Phelps, 1981; "Poisonous Snakes of the World", 1962; Seigel and Collins, 1993)

Commensal/Parasitic Species
  • Apicomplexan Caryospora najae

Economic Importance for Humans: Positive

Red spitting cobras have a unique color to their scales, which are used in textiles. Red spitting cobras are also purchased by enthusiasts due to their color and spitting behaviors. Their venom has been studied (as have the mechanisms behind their very accurate spitting behavior), and has been shown to be a combination of neurotoxins and cytotoxins. Researchers have produced useful antivenins by studying the composition of Naja pallida venom. (Chiszar, et al., 1982; Krimm, et al., 2009; Largen and Rasmussen, 1992; Novak, et al., 1987; Phelps, 1981; Wuster and Broadley, 2003; Wuster and Thorpe, 1992)

Economic Importance for Humans: Negative

Red spitting cobras have lethal venom that can cause severe swelling, paralysis, and skin necrosis. Their venom can be shot at high distances and, if it makes contact with the eye, can cause swelling, conjunctivitis, or blindness if untreated. High costs of live-saving antivenin and loss of ability to work can be negative impacts of a bite. (Krimm, et al., 2009; Largen and Rasmussen, 1992; Mullin and Seigel, 2009; Novak, et al., 1987; Wuster and Broadley, 2003; Wuster and Thorpe, 1992)

  • Negative Impacts
  • injures humans

Conservation Status

Red spitting cobras are not listed on the IUCN Red List page. Although many related species of Naja are listed on Appendix II of CITES (regarding pet trade), red spitting cobras are not listed. This species is not listed on any other federal or international lists. It appears that this species may be currently stable. (Chiszar, et al., 1982; "Guidelines for the Prevention and Clinical Management of Snakebite in Africa", 2010; Novak, et al., 1987; Phelps, 1981; "Poisonous Snakes of the World", 1962; Wuster and Broadley, 2003; Wuster and Broadley, 2007)

Contributors

Alexander Trimarchi (author), Radford University - Fall 2015, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Jacob Vaught (editor), Radford University, Galen Burrell (editor).

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diapause

a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.

diurnal
  1. active during the day, 2. lasting for one day.
drug

a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

infrared/heat

(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

venomous

an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

References

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