Predator-Prey Relationships
There are many kinds of animals in the Zahamena National Park. Each animal is classified as a predator or prey depending on if it is hunting or if it is being hunted. A predator is the animal in an ecosystem that is dominant or hunting the prey. The prey in an ecosystem is typically smaller than the predator, and it is the animal that is being hunted. The predator-prey relationships in the environment are critical, because they help to maintain the balance of life in an ecosystem. If there is a lack of prey, then the predator suffers and there are less of them. If there is an abundance of prey, then the predators will increase in population size resulting in more of the prey to be eaten, so the prey population will decrease over time. Let's take a look at some of the predator-prey relationships in the Zahamena National Park.
The Fossa and Lemurs: The Fossa is a very strong predator in the tropical rain-forests of the Zahamena National Park. They are related to the mongoose and different species of cats. They can be identified by their long tails and big eyes. The fossa hunts during the day and night, and it likes to hunt lemurs, the prey, more specific the giant lemurs (refer to endangered species on the types of species page). The fossa is very limber and can easily jump from tree to tree, which is important because the giant lemurs live amongst the trees. They have retractable claws that help to latch onto trees and their prey. Giant lemurs are becoming extinct, but so is the fossa due to the lack of giant lemurs to consume. If all of the giant lemurs become completely extinct, then the fossa will suffer and potentially become extinct also. However, the fossa also feeds on small animals like birds, so if the fossa is able to eat those instead then there would be a smaller chance of extinction. Now, if it were the other way around and the fossa became extinct before all of the giant lemurs, then the giant lemurs would have a better chance of survival. This is because there would be less factors pushing for the giant lemur's extinction. (link 1, 16, 17)
Click here to see a video of the Fossa
The Mongoose and Snakes: The mongoose in Zahamena is another example of a predator. They can be described as looking like a weasel, because they are long and thin. Typically they live in a large group, and they feed on snakes. Snakes in this relationship are the prey, but in other predator-prey relationships snakes could be described as a predator. The mongoose will attack, venemous snakes in the Zahamena National Park, and eat them in a few bites. They do so by sticking the snakes head in their mouth and chomping down. If the mongoose did not exist or was removed from the environment, then snakes wouldn't have as many threats. However, other species such as the Red Owl of Madagascar would have more food for themselves, therefore allowing the population to thrive. However, if venomous snakes were removed from the environment, the mongoose would have to focus on other things that it likes to eat. This includes smaller rodents, amphibians, and occasionally nuts and fruits if they cannot find any meat to eat. (19)
The Role of Predation in This Ecosystem
Predation in an ecosystem not only controls who eats what and where energy is transported, but it also controls and maintains population growth. The predators eat the prey, and they both help maintain each other's populations so that one doesn't get too big and the other doesn't die off. This goes for every predator-prey relationship out there, including the tropical rainforest. Everything from the primary producers to the tertiary consumers. The primary producers affect the primary consumers, who affects the secondary consumers, and so on. Let's take a look at a few examples:
Kohila: The Kohila is a large fern which is a primary producer in the Zahamena National Park's rain-forest. The fern provides a food sources for many primary consumers, which are the herbivores, like sloths and lemurs. In this example, the sloths and lemurs are the predators, while the kohila fern is the prey. The kohila provides energy for the sloths and lemurs, and helps to keep their populations growing. If the fern was not in the environment, then the lemurs and sloths would have to find a different food source, which could result in a slight decrease in their populations. However, with an open niche without the kohila, a new organism can move in and take its position, but it would not have the exact same effect as the kohila would have. If the sloths and lemurs decreased in the ecosystem, then they would not be eating the fern as much. This would cause for an increase in the amount of Kohila, and it could potentially become a new food source for another population. The predators and prey help to maintain each's population, so that one does not exceed the other by too much, and vise versa. (10, 11)
Leopards: In most tropical rainforests, including Zahamena National Park, leopards are an insanely dangerous predator to many types of prey. They are a tertiary consumer. The leopard is becoming rare due to the lack of resources it has to eat, they are being hunted by humans, and deforestation. Leopards can be identified by their unique fur pattern with a gold coat and black spots. They are a large cat species. Leopards are carnivores that eat many smaller animals including the birds and lemurs (the prey) of the national park. Since the Zahamena National Park does have so many endangered species, this could cause an issue in the populations of each predator and prey. Lemurs and bird's species help to keep up the leopards numbers, however since those animals are now becoming extinct, it is harder for the leopards to find food. If the birds and lemurs were removed from the environment, then the leopard population would decrease. If the leopards were removed from the environment, then the numbers of birds and lemurs would increase, because the big cat would not be hunting them; there would be fewer threats. (11)