Geographic Range
Bitis arietans
is found throughout Sub-Saharan Africa and the Arabian Peninsula.
Habitat
Puff adders are found in areas that meet certain requirements such as a permanent
source of water, warm climate, and cover for the snake. This can include semi-arid
deserts and rainforests, but more often the habitat of the Puff Adder is open forests,
grasslands, and savannahs (Cansdale, 1961; Po, 2018)
- Habitat Regions
- temperate
- tropical
- terrestrial
- Terrestrial Biomes
- desert or dune
- savanna or grassland
- forest
- rainforest
Physical Description
Puff adders are stocky snakes that rarely reach over a meter in length but have been
known to reach up to 1.5 meters and weigh 4.5 to 6.8 kilograms. Females tend to have
a slightly shorter tail than males, but otherwise the sexes are externally similar;
additionally, Saudi Arabian specimens are shorter on average (0.7 meters rather than
0.8 meters average) and have slightly different venom composition. The Puff Adder
has a thick, triangular shaped head and its 5-centimeter-long solenoglyphous fangs
fold into the mouth on rotating maxillae. These fangs deliver a powerful hemotoxic
venom that disrupts the formation of platelets and coagulation of blood. In order
to blend in with sandy soil, the Puff Adder has brown or buff skin covered in keeled
scales that vary in color from shades of brown to a reddish or melanistic tint. Dark
and light chevrons pattern the snake’s dorsal side to break up the snake’s form against
the ground. This patterning is particularly pronounced in lighter colored specimens.
The ventral scutes of the snake tends to be much lighter than the dorsal scales and
range from a cream color to a light-yellow hue (Branch, 1998; Cansdale, 1961; Currier,
2012; Po, 2018)
- Other Physical Features
- ectothermic
- venomous
- Sexual Dimorphism
- sexes alike
Development
Fertilization is internal and male individuals fertilize females using a hemipene.
Puff adders are viviparous and, upon birth, the young must feed and defend themselves.
Individuals continue to feed and shed throughout their lives since growth is indeterminate.
Growth rates in wild specimens have not been extensively studied, but in captive snakes
growth occurs at an almost exponential level during juvenile phases, slowing after
maturity (Po, 2018; Rosi, 1988).
- Development - Life Cycle
- indeterminate growth
Reproduction
Mating typically occurs between October and December, and during this time males will
fight over potential mates. Courtship can last up to an hour and displays entail the
male following and tongue flicking at the female. Males then convulse and attempt
to lift the females tail until they are able to climb on top of the female. Once on
top of the female, males continue to writhe around until she either rejects him or
opens her cloaca for mating. Intromission is internal via use of one of two of the
male's hemipenes. Both sexes undulate their tales during the course of the courtship.
Both males and females can have multiple mates. Females typically give birth in April
and can have from 20-40 offspring at one time. (Branch, 1998; Po, 2018; Rosi, 1988)
- Mating System
- polygynandrous (promiscuous)
Mating typically occurs between October and December, and females typically give birth
in April. Females can have from 20-40 offspring per litter, and have been known to
expel unfertilized eggs while birthing the live offspring. Offspring have been found
to weigh 14-25 grams at birth and be 23.5-25.5 cm in length, and males and females
can be distinguished due to differences in tail length. Sexual maturity is reached
at four years of age. (Branch, 1998; Po, 2018; Rosi, 1988)
- Key Reproductive Features
- seasonal breeding
- sexual
- fertilization
- viviparous
There is no known parental care in this species (Po, 2018)
- Parental Investment
- no parental involvement
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
provisioning
Lifespan/Longevity
The oldest captive puff adder lived almost 16 years, however it is likely that wild
snakes would have a shorter life expectancy due to predation and lack of consistent
food sources. There is insufficient data available to give an estimate as to expected
life expectancy in wild specimens (Branch, 1998; Po, 2018)
Behavior
Puff adders are solitary ambush predators. They use tactics such as lingual and caudal
luring to bring prey within striking distance. Puff adders use their strong hemotoxic
venom to incapacitate prey without having to hold on to them, which prevents injury
to the snake. This behavior is seen in almost all cases when the snake attempts to
catch large prey, but small prey will sometimes be held in the mouth. When threatened,
this species will hiss and puff up to appear larger, giving them their name (Clauss
and Clauss, 2002; Glaudas and Alexander, 2017; Po 2018)
- Key Behaviors
- terricolous
- nocturnal
- motile
- sedentary
- aestivation
- solitary
- dominance hierarchies
Home Range
Not much information is available regarding the home range of the Puff Adder, but
individuals tend to be fairly sessile and may lie in ambush in the same spot for several
weeks.
Communication and Perception
Puff adders use an array of senses to perceive their environment including tactile,
chemical, vibrational, and heat. Chemical and heat signals are vital to determining
when prey is near, and allows the snake to strike at the appropriate time. Upon encounters
with other individuals, they display different behaviors depending on whether they
feel threatened or are attempting to mate. Communication between potential mates is
mostly tactile, as the male will purse the female using his head and tongue. If individuals
sense a threat, they will communicate by giving a deep, hollow hiss and filling their
throat with air. Before striking, the Puff Adder will assume an S-shaped posture,
often the last warning before a strike occurs (Branch, 1988; Clauss and Clauss, 2002;
Rosi, 1988)
- Perception Channels
- visual
- infrared/heat
- tactile
- vibrations
- chemical
Food Habits
Puff adders are carnivores, feeding almost exclusively on terrestrial vertebrates.
The primary prey are rodents (
Aethomys
sp.,
Otomys
sp.,
Rattus
sp.,
Mastomys
sp.,
g.Rhabdomys pumilio
,
Arvicanthis
sp.,
Saccostomus campestris
), but the Puff Adder will also feed on other reptiles (lizards, snakes, tortoises)
and also has fed on birds, frogs (
Schismaderma carens
,
Bufonidae
), and small deer. The typical diet of juveniles includes small rodents, insects,
and small toads or frogs (Miller et al., 2015; Po, 2018)
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- Animal Foods
- birds
- mammals
- amphibians
- reptiles
- insects
Predation
Puff adders avoid predation by using cryptic coloring, as their dorsal patterning
helps them to blend in the with grassland and forest habitats that they are most often
found in. Additionally, they utilize chemical crypsis to avoid predators who seek
them out using olfaction. Finally, Puff Adders can use aggressive behaviors such as
hissing and biting (with envenomation) to deter predators from attempting to predate
them (Claus and Claus, 2002; Miller et al., 2015; Po, 2018)
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Puff Adders act as important predatory species in the ecosystems in which they are
present, and are also prey to some other species. Puff Adder's prevent an overabundance
of pest species such as rodents from decimating wild and agricultural plant species,
and young snakes feed on insects that could cause similar problems (Po, 2018)
Economic Importance for Humans: Positive
Puff adders are an important part of the ecosystem, and provide many benefits to humans.
By controlling rodent populations, these snakes prevent pest populations from consuming
the crops of farmers in the regions. Additionally, the venom of puff adders can be
studied to determine whether it is viable as a medicine in the future (Currier, 2012;
Po, 2018)
- Positive Impacts
- source of medicine or drug
- research and education
- controls pest population
Economic Importance for Humans: Negative
Puff adders are one of the most medically important African snake species because
they are likely responsible for a large portion of the 32,000 snake bite deaths that
occur in Africa annually. These snakes have an extremely hemotoxic venom that prevents
formation of platelets in the bloodstream and also leads to extreme pain, swelling,
and tissue necrosis. With the current antivenin crisis in Africa, the puff adders
have the potential to cause significant harm to humans that they come into contact
with (Currier, 2012)
- Negative Impacts
-
injures humans
- bites or stings
- venomous
Conservation Status
Puff adder populations are currently stable. They are not listed as a species in need of protection (IUCN Red List, 2018)
Additional Links
Contributors
Ally Brown (author), Michigan State University, James Harding (editor), Michigan State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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).
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- 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.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- venomous
-
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
- indeterminate growth
-
Animals with indeterminate growth continue to grow throughout their lives.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- dominance hierarchies
-
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- visual
-
uses sight to communicate
- infrared/heat
-
(as keyword in perception channel section) This animal has a special ability to detect heat from other organisms in its environment.
- tactile
-
uses touch to communicate
- vibrations
-
movements of a hard surface that are produced by animals as signals to others
- chemical
-
uses smells or other chemicals to communicate
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- drug
-
a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease
- venomous
-
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
- carnivore
-
an animal that mainly eats meat
References
Branch, B. 1998. Field guide to snakes and other reptiles of southern Africa . Sanibel Island, Florida: Ralph Curtis Publishing.
Cansdale, G. 1961. West African Snakes . United Kingdom: Longman Group.
Clauss, B., R. Clauss. 2002. Common Amphibians and Reptiles of Botswana . Windhoek, Namibia: Gamsberg Macmillan.
Currier, R. 2012. "INVESTIGATING VENOM SYNTHESIS: EXPLORING THE COMPOSITION, VARIATION AND GENE EXPRESSION DYNAMICS OF BITIS ARIETANS VENOM" (On-line). Accessed December 08, 2018 at https://core.ac.uk/download/pdf/80771038.pdf .
Glaudas, X., G. Alexander. 2017. "A lure at both ends - puff adders leave nothing to chance" (On-line). Accessed December 09, 2018 at https://www.wits.ac.za/news/latest-news/research-news/2017/2017-02/a-lure-at-both-ends---puff-adders-leave-nothing-to-chance.html .
Miller, A., B. Maritz, S. McKay, X. Glaudas, G. Alexander. 2015. An ambusher's arsenal: chemical crypsis in the puff adder (Bitis arietans). Proceedings of Biological Science , 282(1821): 20152182. Accessed December 09, 2018 at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707760/#RSPB20152182C8 .
Po, 2018. "Puff Adder" (On-line). EOL. Accessed December 08, 2018 at https://eol.org/pages/1057058 .
Rosi, R. 1988. THE BREEDING IN CAPTIVITY OF THE PUFF ADDER, BITIS ARIETANS. Litteratura Serpentium , 8(3): 123-133. Accessed December 09, 2018 at http://www.snakesociety.nl/jaargangen/1988e/Litteratura%20Serpentium%208-3%20123-133%20Rosi,%20The%20breeding%20in%20captivity%20of%20Bitis%20arietans.pdf .
Toxinology, WHC. 2018. "Bitis arietans" (On-line). Clinical Toxinology Resources. Accessed December 09, 2018 at http://www.toxinology.com/fusebox.cfm?fuseaction=main.snakes.display&id=SN0200#top .