Introduction
The black mamba is one of the most venomous snakes in the world. A bite from a black mamba can be fatal if the victim does not receive anti-venom treatment quickly. However, there is one animal that has evolved a natural immunity to the venom of the black mamba – the mongoose.
What is the black mamba?
The black mamba (Dendroaspis polylepis) is a highly venomous snake that is native to parts of sub-Saharan Africa. It gets its name from the black color inside its mouth, which it displays when threatened. The black mamba is not only one of the most poisonous snakes, it is also the fastest land snake in the world. It can move up to 12 mph, which makes it extremely dangerous.
Some key facts about the black mamba:
- Scientific name: Dendroaspis polylepis
- Average length: 2-4 m (6.5-13 ft)
- Native habitat: Savannas and rocky areas of southern and eastern Africa
- Diet: Birds, rodents, hyraxes, other snakes
- Venom type: Powerful neurotoxic and cardiotoxic venom
- Average venom yield: 100-400 mg
- LD50: 0.25 mg/kg
The black mamba’s venom consists of powerful neurotoxins and cardiotoxins that can paralyze muscles, cause difficulty breathing, and stop the heart. Even a small amount of venom can be fatal if untreated. Bites can cause symptoms within minutes and death can occur in less than 20 minutes. This makes the black mamba one of the world’s deadliest snakes.
Where are black mambas found?
The black mamba inhabits various types of habitats across a large area of sub-Saharan Africa. Its range extends from Ethiopia and Somalia in the east all the way to South Africa in the south.
Some key locations where black mambas can be found include:
- Eastern, central and southern Africa
- South Africa
- Swaziland
- Namibia
- Botswana
- Zimbabwe
- Mozambique
- Zambia
- Tanzania
- Kenya
- Ethiopia
- Somalia
Within these countries, black mambas occupy varied habitats including rocky savannas, open woodlands, termite mounds, abandoned burrows, and dry riverbeds. They can adapt to rural, agricultural, and even urban landscapes. Black mambas prefer dry environments and often bask in tree branches or on rocks to regulate their body temperature.
The Mongoose
The mongoose is a small carnivorous mammal that has developed an amazing resistance to the venom of the black mamba through specialized acetylcholine receptors. This makes the mongoose one of the only animals capable of surviving a black mamba attack.
What are mongooses?
Mongooses are small diurnal mammals belonging to the Herpestidae family. There are over 30 different mongoose species, the most common being the Egyptian mongoose and the dwarf mongoose.
- Other names: meerkat, ichneumon
- Average size: 1-3 ft long; 2-4 lbs
- Habitats: variety including savannas, forests, deserts
- Range: Africa, southern Europe, Asia
- Diet: small animals, insects, birds, eggs, fruit
- Behavior: diurnal, social animals that live in packs
- Noteworthy features: long bodies, small rounded ears, long tails, short legs, non-retractable claws
Mongooses are found in a wide range of habitats across Africa, southern Europe, and Asia. They live in underground burrows in packs ranging from 5-50 individuals. Mongooses use scents to mark territory and communicate. They are ferocious hunters that feed on small prey including rodents, birds, eggs, reptiles, and insects. Their agility allows them to even kill venomous snakes.
Mongoose species
Some of the most common and well-known mongoose species include:
- Egyptian mongoose
- Slender mongoose
- Dwarf mongoose
- Banded mongoose
- Indian gray mongoose
- Small Asian mongoose
The most widespread mongoose species in Africa is the Egyptian mongoose. The black-tipped slender mongoose is also common in sub-Saharan Africa. The common dwarf mongoose lives in packs across eastern and southern African savannas where black mambas reside.
Mongoose Immunity to Black Mamba Venom
How does the mongoose have immunity to the deadly venom of the black mamba when it is so toxic to most other mammals? Researchers discovered some fascinating evolutionary adaptations in the mongoose that allow it to be unaffected by neurotoxins.
Acetylcholine Receptors
The mongoose is resistant to snake neurotoxins including black mamba venom due to mutations in the acetylcholine receptor sites on its muscle cells. Acetylcholine is a neurotransmitter that activates muscles. Snake neurotoxins bind to these acetylcholine receptors and inhibit muscle contractions, leading to paralysis and death.
However, the mongoose acetylcholine receptors contain special binding sites that prevent the venom neurotoxins from attaching. This provides the mongoose with protection from the dangerous effects of black mamba venom. Even a dose 20 times more than required to kill a rabbit was shown not to impact mongooses.
Neutralizing Factors
In addition to the acetylcholine receptors, researchers found that mongoose serum contains special neutralizing factors that render black mamba venom harmless. When black mamba venom is injected along with mongoose serum into a rabbit, the rabbit survived. The neutralizing factors inactivate the toxic components of the venom.
Behavioral Adaptations
On top of its physiological immunity, the mongoose has also developed unique behaviors when dealing with black mambas:
- The mongoose is highly agile and uses speed and cunning tactics to avoid being bitten by snakes.
- It will use quick coordinated attacks to pin down and kill snakes, targeting vital areas like the head/neck.
- Mongooses are pack animals, so they will work together to distract and kill snakes.
- The thick mongoose coat protects from penetration of fangs.
- Mongooses are resistant to the pain from venomous bites.
These behavioral adaptations complement the mongoose’s innate physical immunity when confronted by black mambas. Even if bitten, they can survive long enough to kill the snake.
Mongoose vs Black Mamba Encounters
When a mongoose and black mamba encounter one another in the wild, fierce battles often ensue. The mongoose has the advantage of speed and agility over the black mamba, along with immunity to its venom.
Typical mongoose attack strategy
Mongooses use complex attack strategies when confronting black mambas:
- The mongoose uses its quick reflexes to avoid the mamba’s initial strikes.
- It will try to attack from behind or exploit vulnerabilities like the snake’s head/neck.
- The mongoose avoids the fangs and aims to pin the mamba down.
- Other pack members may join in harassing the snake from all directions.
- The mongoose ultimately goes for a killing blow on the head or neck and then consumes the snake.
How does the black mamba try to defend itself?
Black mambas use intimidation and speed to defend against mongooses:
- The mamba will initially rear up and spread a neck flap to seem larger.
- It will repeatedly strike out at high speeds towards the mongoose.
- The mamba tries to get away from the mongoose into vegetation or burrows.
- As a last resort, it will roll onto its back and strike with all four fangs exposed.
Despite the mamba’s defenses, the agile mongoose has the advantage with its resistance to venom and pack numbers, allowing it to make a kill.
Why the Mongoose Developed Black Mamba Immunity
The evolution of venom immunity in the mongoose was driven by the following ecological factors:
Dietary Overlap
Since mongooses prey on reptiles like snakes and eggs, developing resistance to snake venom provided an important adaptive advantage. Immunity allows mongooses to eat venomous snakes with no ill effects.
Shared Habitats
Mongooses and black mambas occupy overlapping habitats like savannas, woodlands, and rocky areas across Africa. More interaction and higher chances of potentially fatal snake bites drove the evolution of immunity.
Arms Race
There was an evolutionary arms race between mongooses and snakes like black mambas. As snakes evolved more toxic venom, mongooses had to adapt with countermeasures to neutralize the venom, promoting co-evolution.
Reproductive Advantage
Venom immunity gave mongooses that could feed on snakes and survive bites a reproductive edge. They were able to survive, grow faster, have more offspring, and pass down immunity genes.
Other Mongoose Snake Interactions
Besides the black mamba, the mongoose preys on other venomous snake species and displays remarkable immunity:
Cobra
Mongooses battle cobras in a similar manner to black mambas. Their speed and agility helps them avoid bites and attack the cobra’s head. Mongooses are resistant to neurotoxins in cobra venom.
Viper
Vipers are also preyed upon by mongooses. They avoid the quick viper strikes and attack from behind. Hemotoxic viper venom has little effect on the mongoose.
Rattlesnake
Rattlesnakes and mongooses compete in some ecosystems. Mongooses show immunity to rattlesnake venom through acetylcholine receptor mutations.
King Cobra
The large king cobra is one of the mongoose’s most impressive snake prey. The mongoose relies on pack numbers and aggression to overwhelm and kill the king cobra.
Conclusion
The mongoose is a snake predator that has undergone remarkable evolutionary adaptations rendering it immune even to the deadly venom of the black mamba. This immunity is based on mutations to the mongoose’s acetylcholine receptors along with protective factors in its blood serum. These adaptations allow the quick and agile mongoose to attack and consume black mambas with no ill effects. The mongoose’s immunity developed through factors like dietary overlap with snakes, shared habitats, and an evolutionary arms race. This venom resistance gives the mongoose a distinct ecological advantage over other mammals when interacting with snakes like the aggressive black mamba.