Most reptiles such as lizards and ants can release blood from their body naturally. One of the most popular reptiles in this category is the Horned lizard. There are six species of horned lizards that are capable of shooting blood through their eyes.
Horned Lizards
Around the world, there are approximately 17 known species of horned lizards. They are categorized into various kinds based on their color, size, and number of horns.
- The body is wide and flat with short legs. Guatemala, Mexico houses these lizards across the deserts of Arizona and California, and the dry parts of Canada.
- They prefer dry climatic conditions.
- However, recent studies claim that there has been a decline in the population of horned lizards rapidly. This is mainly due to human activities that cause the loss of natural habitats for these animals.
- There has been massive clearance of forests due to human activities such as real estate development and road construction, the planting of non-native grasses, conversion of native land to pastureland, and agricultural fields.
- Fire ants are also a major reason for the population decline. Fire ants don’t harm these lizards directly, but they are responsible for the disappearance of other ants in the area.
- The other ants serve as food for the lizards too. This competition for food has led to the lizards to reduce in numbers.
- Until the mid-20th century, they were popular choices as pets and were sold at very high prices. These animals have special nutritional requirements, which most owners fail, leading to their deaths, causing a massive downfall in their population.
- Finally in the late ’90s laws were passed for the protection of horned lizards.
- They have been listed as endangered species, in 2014, and may be on the verge of extinction very soon.
- These reptiles are known for their characterizing feature, of releasing blood through their eyes.
Auto hemorrhaging
This process, also known as reflex bleeding, animals deliberately ejecting blood out of their bodies. Usually, insects are known for this ability, however, it is seen in some reptiles too.
- Most lizards tend to squirt blood when they are under acute pressure.
- Most animals can control this pressure and regulate the flow of blood. For example, a horned lizard may release the blood to attack a predator, or it may not release the blood and only let blood flow to a certain extent to release toxins from the eyes.
- Horned lizards are potential prey for many predators. To fight these predators, they use this unique defense mechanism that involves shooting out blood from their eyes.
- The sinuses are flooded and the eye sockets release blood from these. This frightens the predator, and they flee.
Mechanism
- Lizards are cold-blooded animals and absorb heat from the environment. However, the heat is not evenly distributed in the body, the head is heated up more than the body.
- This creates high blood pressure in the head, causing the blood to flow out of the eyes.
- Lizards can control the flow of blood in their body, therefore being able to control the blood pressure of the body
- The horned lizard possesses two constricting muscles around the veins near the eyes. When these muscles contract, blood doesn’t flow into the heart, instead the blood is directed towards the head. This causes the sinuses to bulge.
- When the muscles are contracted further, the membranes of the sinuses burst. The blood in the sinus flows out of the eye sockets.
- Horned lizards can repeat this process multiple times within a short span of time.
- However, a horned lizard won’t release blood until and unless the predator tries to swallow it.
- They do so, because otherwise the bloodstream may hit the eye of the predator or simply fall on the ground with no effect on the predator.
Uses
- Animals like hawks, roadrunners, snakes, coyotes, foxes, wolves, bobcats, mice, etc. feed on these lizards.
- Horned lizards possess short legs. Therefore, they can’t run fast, making it easy for predators to prey on them.
- These lizards, capable of camouflaging, try to make themselves invisible to the predator.
- If they still, manage to get caught, inside the predator’s mouth the predator takes time to crush the horns before it can be eaten or swallowed. The lizards shoot blood into the animal’s mouth, forcing it to open its mouth.
- When the mouth is open, the lizard escapes, while the predator is busy getting the liquid out of its mouth.
- Most predators have a negative reaction to the taste of blood, though to humans it will taste acrid as per researchers.
This mechanism is applied for many other purposes too. Horned lizards get rid of the foreign particles that enter the eye, via this method, but in this case, the membranes are not ruptured. The sinuses are allowed to bulge to the extent that they don’t burst. When they are contracted, often the toxins, dirt, and soil fall off, due to the pressure created by contraction. This pressure is enough to not let the sinus membranes burst and release blood too.
- The lizards also keep their bodies warm, through this method. At night these lizards bury their head in the soil to keep warm.
- In the morning when the sun rises, they lift their head, allowing all the blood to fill the large cavities in the head. The heat from the sun slowly warms up the body and the lizards allow the warm blood to flow back into the body, keeping it warm.
Horned lizards are cute and don’t harm human beings. This may seem favorable to adopt them as pets, but it is highly recommended to not adopt them as pets. Most countries have laws that prevent the selling of lizards. Mexico continues to adopt them as pets, despite federal laws being implemented. They are essentially wild animals, who need special dietary requirements such as ascorbic acid. It is difficult to provide them with these, at homes and farms. Hence it is advised to not bring them out of their natural habitat.