Competition and Predation

Competition and Predation

Shiken premium Upgrade Banner

Competition when there isn't enough resources to go around and different organisms fight to get them. Predation is a kind of competition where a predator hunts and eats its prey. These are biotic factors, which means they come from living things and can affect the size of a population. Biotic factors are a part of ecosystems, which are made up of living things like animals and plants, and non-living things like water and rocks. There are two kinds of competition in biology: competition and predation.

Intraspecific competition Interspecific competition

What is intraspecific competition?

When members of the same species compete with each other, it's called intraspecific competition. The available in the habitat how there, is capacity more individuals, there's less competition. when there are fewer resources or the population getting too big, there's more competition. So, the size of the population depends on how much competition there is for resources.

This phenomenon is visualised in the following graph.

Population size and carrying capacity

When two members of the same species compete with each other, it's called intraspecific competition. The carrying capacity the most significant population size that an environment can sustain with the available resources. Different resources are linked, which affects competition. For example, imagine a population of apes competing for territory that provides food and attracts new mates for them and their families. The habitat has limited space, so the size of the territory will depend on the resources available. If there are plenty of resources, the territory size can be small, and more territories can fit in the area, leading to less competition. But when resources are scarce, territories need to be more extensive, leading to fewer territories and more competition between males.

What is interspecific competition?

Interspecific competition happens when individuals of different species compete for resources. The competitive exclusion principle states that no two species can occupy the same niche in the same habitat. If one species has a slight advantage over the other, it will outcompete the other to the point of extinction. So, two species that use the same limited resource cannot coexist at constant population levels. The species that uses the resource most effectively will eliminate the other.

The competitive exclusion principle

The competitive exclusion principle states that when two species use the same limited resource, only one will survive in the long term, and the one that uses the resource more effectively will eliminate the other.

For example, suppose there are two populations of fish in a lake that eat the same food. Population A can tolerate slightly higher temperatures than Population B. During the summer, Population A is more likely to survive and reproduce, leading to an increase in their population size and consumption of food. On the other hand, Population B is less likely to survive the increase in temperature, and there is less food available for them to eat. Over time, Population A's advantages will continue to build up, and Population B's size will decrease. However, environmental conditions can change, and if the lake's temperature decreases, Population B might have the competitive advantage and eventually outcompete Population A. It's crucial to remember that even small advantages can grow over time, leading to significant differences in the population size of different species.

Investigating the effects of competition on population size

While competition can significantly impact the size of a population in theory, it can be challenging to prove in practice due to various factors. Abiotic changes in the environment can interact with or mask the effects of biotic factors, making it challenging to isolate the impact of competition. Additionally, competition can take some time to affect a population, making it difficult to identify and easy to misattribute to other factors. Furthermore, establishing causal links in natural populations can be challenging, especially when studying rare or protected species. Researchers may have to rely on incomplete, correlational data that may not accurately reflect the population's actual situation. Therefore, while competition can play a significant role in affecting population sizes, proving it in practice can be challenging due to various factors.

What is predation?

Predation is the process by which one organism consumes another organism, where the predator is the organism that feeds, and the prey is the organism being consumed.

Predators and prey often have closely linked evolutionary relationships, as predators must evolve adaptations that enable them to catch their prey better, while prey must evolve adaptations that help them escape their predators.

For example, barn owls are predators that feed on field mice. Barn owls have developed excellent night vision and wide wingspans that allow them to glide silently, while field mice have developed coloration that helps them blend into their environment, as well as highly sensitive hearing and rapid running speeds that increase their chances of escaping.

It is worth noting that animals can also play both predator and prey roles. For instance, while we often think of herbivores like field mice as prey, from the perspective of the plants they eat, they can also be considered as predators. Ultimately, predator-prey relationships play a crucial role in shaping the evolution and diversity of life on earth.

Five types of predation

The predator-prey relationship has a cyclical on population size. For example, consider a population of owls that feed on a population of mice.

Initially, the owl population will grow as it feeds on the abundant population of mice. The growing owl population will then consume more mice, which will reduce the mice population. With fewer mice available, the owls will face increased competition for food, which will eventually lead to a decline in the owl population as some individuals cannot catch enough food to survive and reproduce. As a result of the reduced predator population, more mice will survive and reproduce, leading to an increase in the mice population. The increase in the mice population will replenish the food supply for the owls, enabling them to recover their numbers and start the cycle anew.

Thus, the predator-prey relationship can have a regulating effect on population size, preventing either population from growing too large or too small. This relationship plays an essential role balancing and ecosystems

Why aren’t the prey exterminated by the predator?

In laboratory experiments, predators can quickly exterminate prey populations. However, in natural settings, this rarely happens due to a wide range of external factors that allow prey to survive. These factors include the prey population's ability to disperse over a larger and more varied area, making them harder to find and catch. Predators may also have to contend with competition from other potential predators, survive the effects of environmental factors like heat or cold, and navigate difficult terrain.

In biology, competition arises when two or more individuals share a limited resource. There are two types of competition: intraspecific competition and interspecific competition. Intraspecific competition occurs between members of the same species, while interspecific competition occurs between members of different species. According to the competitive exclusion principle, two species that use the same limited resource cannot coexist at constant population levels; the species that uses the resources more effectively will eliminate the other.

Predation, on the other hand, is a process wherein one organism consumes another organism. The predator-prey relationship follows a cyclical pattern, where predators consume prey, reducing their population, leading to increased competition among predators. Eventually, the predator population declines, allowing the prey population to increase, and the cycle begins anew. Overall, competition and predation are two key ecological processes that shape the dynamics of populations and ecosystems.

Competition and Predation

What are 5 types of predation?


What is the main difference between a predator and a prey? 

The predator kills and eats the prey for food. 

What is the difference between intraspecific and interspecific competition?

Interspecific competition occurs between members of different species whereas intraspecific occurs between members of the same species.

What does interspecific competition mean?

Competition between members of different species.

Join Shiken For FREE

Gumbo Study Buddy

Try Shiken Premium for free

Start creating interactive learning content in minutes with Shiken. 96% of learners report 2x faster learning.
Try Shiken for free
Free 14 day trial
Cancel anytime
20k+ learners globally
Shiken UI showing questions and overall results.