Predator–Prey Relationships | dayline.info
More recently, scientists have discovered that predation can also influence the size of the prey population by acting as a top-down control. In reality, the. Learn about predator-prey relationships in the African savannah. Fact file includes threats, conservation, photos, videos and a chance to become a science . Predator–Prey RelationshipsIntroductionPredator-prey relations refer to the interactions between two species where one species is the hunted food source for.
The fastest lions are able to catch food and eat, so they survive and reproduce, and gradually, faster lions make up more and more of the population. The fastest zebras are able to escape the lions, so they survive and reproduce, and gradually, faster zebras make up more and more of the population. An important thing to realize is that as both organisms become faster to adapt to their environments, their relationship remains the same: This is true in all predator-prey relationships.
Another example of predator-prey evolution is that of the Galapagos tortoise. Galapagos tortoises eat the branches of the cactus plants that grow on the Galapagos islands. On one of the islands, where long-necked tortoises live, the branches are higher off the ground. On another island, where short-necked tortoises live, the branches are lower down.
The cactuses, the prey, may have evolved high branches so that the tortoises, the predators, can't reach them. Note, however, not just in this case but in any case of co-evolution and evolution, that there is always more than one cause that forces an organism to adapt, and though it is likely that the higher branches are to avoid the tortoises, it is also possible that it was a different cause, such as the sun, the ocean, or a different organism.
Bears, for example, feed on berries, a rabbit feeds on lettuce, and a grasshopper feeds on leaves. Predators and prey exist among even the simplest life forms on Earth, single-celled organisms called bacteria.
Predator-prey relationships in the African savannah
The bacteria Bdellovibrio feed on other bacteria that are bioluminescent they produce internal light due to a chemical reaction. Indeed, the study of Bdellovibrio predation has revealed a great deal of the mechanics of predation and how the predator and prey populations fluctuate in number over time in a related fashion. Predator and prey populations respond dynamically to one another.
When the numbers of a prey such as rabbits explode, the abundance at this level of the food chain supports higher numbers of predator populations such as foxes. If the rabbit population is over-exploited or drops due to disease or some other calamity, the predator population will soon decline.
Over time, the two populations cycle up and down in number.
Predator-prey relationships in the African savannah | Arkive
In many higher organisms, the prey can be killed by the predator prior to feeding. For example, a cheetah will stalk, run down, and kill its prey examples include the gazelle, wildebeest, springbok, impala, and zebra. In contrast, fish and seals that are the prey of some species of shark are examples of prey that is fed on while still alive. The key aspect of a predator-prey relationship is the direct effect that the predation has on numbers of their prey.
Historical Background and Scientific Foundations Predators and prey have evolved together, and their relationship is ancient.
For example, fossils dating back nearly million years have revealed evidence that extinct animals known as Hederellids were the prey of an as yet unknown creature that killed them by drilling holes through their tubular shells. As species developed and flourished, other species exploited them as their food. A species that has become a successful predator and has survived has developed a few or a number of strategies to acquire the prey.
The predator may use speed; stealth the ability to approach unnoticed by being quiet and deliberate in its movements, or by approaching from upwind ; camouflage; a highly developed sense of smell, sight, or hearing; tolerance to poison produced by the prey; production of its own prey-killing poison; or an anatomy that permits the prey to be eaten or digested.
Likewise, the prey has strategies to help it avoid being killed by a predator. A prey species can also use the aforementioned attributes listed for the predator to avoid being caught and killed. The fitness of the prey population—the number of individuals in the population, chance of being able to reproduce, and chance of survival—is controlled by the predator population.
The ways in which predators stalk, kill, and feed on their prey can be used in a classification scheme. A so-called true predator kills the prey and then feeds on it. True predation usually does not involve harm to the prey prior to death. For example, prior to being chased down and killed by a cheetah, a gazelle is healthy. Cattle that graze on grass are not considered a predator-prey relationship, as only a portion of the grass is eaten, with the intact roots permitting re-growth of the grassy stalk to occur.
A predator and its prey can both be microscopic, as is the case with the bacterium Bdellovibrio and other Gram-negative bacteria. But, the size difference between predator and its prey can be immense. Predator-prey relationships can be more complex than a simple one-to-one relationship, because a species that is the predator or the prey in one circumstance can be the opposite in a relationship with different species. For example, birds such as the blue jay that prey on insects can become the prey for snakes, and the predatory snakes can be the prey of birds such as hawks.
This pattern is known as a hierarchy or a food chain. The hierarchy does not go on indefinitely, and ends at what is described as the top of the food chain. For example, in some ocean ecosystems, sharks are at the pinnacle of the food chain. Other than humans, such so-called apex predators are not prey to any other species. This relationship applies only to the particular ecosystem that the apex predator is in.
If transferred to a different ecosystem, an apex predator could become prey. For example, the wolf, which is at the top of the food chain in northern forests and tundra environments, could become the prey of lions and crocodiles if it were present in an African ecosystem.
Predator-prey relationships involve detection of the prey, pursuit and capture of the prey, and feeding. Adaptations such as camouflage can make a prey species better able to avoid detection.
By blending into the background foliage or landscape and remaining motionless, an insect or animal offers no visual cue to a predator since it mimics its surroundings. There are many examples of mimicry in predator-prey relationships. Some moths have markings on their outer wings that resemble the eyes of an owl or that make the creature look larger in size.
Predation - Wikipedia
Insects popularly known as walking sticks appear similar to the twigs of the plants they inhabit. Another insect species called the praying mantis appears leaflike. The vertical stripes cause individual zebras in a herd to blend together when viewed for a distance.
To a predator like a lion, the huge shape is not recognized as a potential source of food. Camouflage can also be a strategy used by a predator to avoid detection by prey. An example is the polar bearwhose white color blends in with snow, reducing the likelihood that the bear will be detected as it approaches its prey.
In this case, the same strategy and color can be utilized by young seals, since their color allows them to be invisible as they lie on the snowy surface. The community of individuals and the physical components of the environment in a certain area.
A sequence of organisms, each of which uses the next lower member of the sequence as a food source. An interconnected set of all the food chains in the same ecosystem.
The natural location of an organism or a population. Factors that influence the evolution of an organism. An example is the overuse of antibiotics, which provides a selection pressure for the development of antibiotic resistance in bacteria.
The opposite of camouflage can occur. A prey can be vividly colored or have a pattern that is similar to another species that is poisonous or otherwise undesirable to the predator. A successful predator must judge when pursuit of a prey is worth continuing and when to abandon the chase.
This is because the pursuit requires energy.