15 Intraspecific Competition Examples

Intraspecific Competition Examples

Intraspecies competition is the rivalry that happens within a species over a limited amount of resources. Such stiff competition can be quite devastating and lead to serious loss of population density of a particular species.

But such competition also ensures that the evolutionary rule of “survival of the fittest” is fulfilled.Only the dominant and fittest of the organisms within a given species will end up surviving the competition and transferring their stronger genes.

Generally, intraspecific competition occurs due to scarcity over the following resources:

  • Food and water
  • Shelter
  • Territory
  • Light
  • Mates

Under conditions where there is an abundance of all kinds of available resources, then intraspecific competition will subside and the population of that species will end up increasing at a rapid pace.

However, with scarcity of resources, severe competition breaks out over a species population regarding the procurement of those resources.

The weaker or shy members of the population get negatively affected owing to such competition and only the dominant ones end up surviving and hence get to reproduce.

There are two main types of intraspecific competition:

  • Direct: Here the species members indulge in direct confrontations over one another to sort out a particular solution to a problem or regarding ownership of a particular resource or in showing off their strength to other members of the species. It can be in the form of fighting, ritualistic challenges, or stealing.
  • Indirect: Here the organisms are not engaged in direct confrontations with one another. When a shared resource gets depleted and scarcity of such resources can lead to a sudden increase in competition within the species and under such circumstances, only the “fittest” of the individuals end up getting all the benefits whereas the weaker ones perish.

Intraspecific Competition Examples

There are many instances of intraspecific competition in nature and here we share with you 15 such examples.

1.  Grizzly Bear Competition

Summary: Due to scarcity of fish, Grizzly bears will fight among themselves for prime fishing spots.

Grizzly bears that live in coastal regions or around lakes and rivers are very well versed in catching fish. Bears love salmon and they use their sharp claws and teeth for catching the fish.

Grizzly bears are regarded as better catchers of fish even within the bear domain and if these bears dominate a territory that is at a favorable position (near the upper course of the rivers), they will end up consuming a huge share of the fish population and the bears living in other points of the stream can find it hard to get the same supply of fishes.

So, during seasons when fish are scarce, these bears can engage in tough competition with one another to occupy the best locations that are ideal for fish hunting.

2. Wolf Spider Competition

Summary: Wolf Spiders often find themselves in habitats with not enough food, leading to indirect interspecific competition where only the best hunters survive.

This is an example of indirect intraspecific competition where the organisms are not involved in any confrontation or fight among themselves. However, still, an unintentional match erupts among its population when the food resources are finite in amount.

As the amount of available food decreases and the wolf spider population keeps on increasing, the species as a whole faces a serious existential threat. Only the fastest and smartest wolf spiders will thrive, while the rest starve due to inability to successfully hunt.

This kind of indirect intraspecies competition is not only limited to these spiders but among all kinds of organisms in the world. It happens when the food resource or the habitat zone is limited and doesn’t expand with the expansion in the species population.

With declining resources, the increase of the spider popularity will slow down and after some time will show a downward growth curve until balance between resources and population is met.

3. Salamander Competition

Summary: Salamanders compete aggressively for procuring resources. The most aggressive Salamanders have shown a greater chance at survival and reproduction.

Salamanders are known to demonstrate different degrees of aggression within their species based on resource availability.

When there is a scarcity of food resources, salamanders within a population can get aggressive towards one another. This applies to not all members of the population but a sizeable number of them.

Often it can be found that aggressive salamanders have a greater chance of reproducing and passing on their dominant genes than other salamanders that are non-aggressive and shy. This is because, under conditions where resources are scarce, aggressiveness plays a big role in obtaining the required resources which are seen as a dominant trait to attract better mates.

4. Plant Allelopathy

Summary: Plants will suppress the growth of other nearby plants when resources such as sunlight are sparse. Some even let off chemicals that suppress other plants’ growth in a process called allelopathy.

Stiff intraspecific competition is witnessed among members of different plant species, particularly the ones that grow under conditions where resources are limited.

Often plant saplings are found to grow under the shade of large trees and these trees end up using the majority of available sunlight.

Under such difficult conditions, it becomes problematic for the newer varieties of the same plant species to survive.The pre-existing plants of the older generations will have an established system in place to make use of the limited resources, which will make it hard for the younger plants to thrive.

To adapt, the majority of plants have evolved to develop long-distance seed dispersal mechanisms that ensure that majority of their newer plants will germinate and grow far enough away from the cover of the mother.

In many other plants that grow under such scarce conditions, certain mechanisms called allelopathy can be seen where these plants end up releasing certain chemicals in their environment which negatively impacts the growth of the other plants growing in its immediate proximity.

Such chemicals can be transmitted both through leaf pores or through underground means and they heavily impact the photosynthesis process in other plants and can even be the reasons behind their death.

5. Bird Courtship

Summary: Courtship, where an animal has to lure a mate, is another example of intraspecific competition. Only the most convincing animals get the mate. This is common among birds (and humans!).

Almost all varieties of birds have their unique way of trying to impress their opposite-gender counterparts. This courtship ritual is different depending on the bird species.

In most varieties, the male birds compete with one another to get the attention of the female birds whereas in some varieties the female birds also take part in such courtship rituals.

Some examples include:

  • Costa hummingbirds demonstrate their high acrobatic skills of flying around their potential mates to show their superior body flexibility.
  • Cranes try to get the attention of female cranes by doing odd dance moves. They will keep on flapping their wings and move their long necks back and forth continuously. If nothing works they will even start throwing grass and mud into the air. Once it gains the attention of the females he will try to dance together.
  • Male Red-capped Manakinshave to perform moonwalks to woo their female counterparts! These birds need to slide along on the branches of the trees seamlessly so that the movement won’t show any kind of friction. Needless to say, the best-performing ones get the attention of the females.

6. Buck Fights

Summary: Like birds, male deer (bucks) have to compete to find a mate. But unlike birds (whose method is usually to dance to impress the females), bucks get into fights with one another in front of females to demonstrate strength and dominance.

During every breeding season, male deers need to participate in strength demonstration to find a suitable mate for themselves. Such direct intraspecific interactions are very common among many different organisms, especially during the breeding season.

Male deer engage in direct fights with other bucks where they lock horns with one another and show off their brute strength in the hopes of gaining the attention of female deer.

The two bucks that decide to challenge one another start moving in a circular pattern locking eyes.

Then they slowly move closer to each other and charge hard towards each other. The antlers on their head are placed in such a way evolutionary that their horns get locked with one another and then it becomes a competition of brute strength.

The antlers of deer have developed in such a manner so that they get easily locked with the antlers of other deer as this helps in preventing any kind of direct damage to the deer head or face. This further decreases their chances of getting life-threatening injuries.

7. Horn Locking

Summary: The above example is not the only example of using horns to attract a mate. Even beetles compete for mates by showing-off their horns to their potential mates!

There are many organisms both in the mammalian and insect world that has got antlers and horns on the head of their males, as that further allows them to showcase their strength during the mate selection competition.

Organisms like bulls, deers, beetles, stags, etc, have their males compete against each other by locking horns and the winner gets to mate with the most number of females.

8. Flamingo Competition

Summary: Only the dominant flamingoes in a flock get the opportunity to mate.

Mating is a very important issue or even the most important event in the lives of many living animals. So often only the dominant members of the species end up finding mates while the weaker members of the group find it hard to mate as the dominant ones end up mating with multiple partners.

So, only the dominant ones get to pass their genes on to the next generation. This is something commonly seen in Flamingoes.

These birds not only compete with each other for mates but also for procuring food and territories. The paired birds are generally found to be more aggressive than single birds.

This is because the paired birds have a greater demand for resources as they are likely to mate and so procuring food while defending the newly born babies is quite important for them.

9. Penguin Competition

Summary: Like flamingoes, penguinscompete with each other to find a mate. The fortunate winner often wins his female for life.

Penguins are known to be very competitive with each other in selecting their mates and most commonly they are monogamous for a particular breeding season.

In fact, a study has shown that there is also a high chance that the same female penguin will look to mate with the same male penguin in the next breeding season as well.

10. Barnacles Competing for Surface Area

Summary: Barnaclescompete against each other for sparse rock surface area. A barnacle will spread itself out and cling on for dear life, trying to get as much rockface underfoot as possible.

Barnacles are organisms that have evolved in a way that allows them to easily attach their body to other animals or certain inanimate objects like rocks, ships, etc. Securing a particular attach point and having maximal control over the surface area of that attaching body is of maximum importance to the barnacles.

They obtain their food from the continuously moving water hence they need to dominate a larger surface area as that will enhance their chances of procuring a greater amount of food.

So stiff competition exists among the barnacles where they compete against each other for attaching themselves and controlling the rock surface area.

Even an extra inch of control area can increase their probability of getting more resources by quite a bit and that can become a deciding factor between life and death for them.

11. Wild Dog Competition for Food

Summary: Food is sparse for wild dogs. They will often fight among themselves for food.

In situations when food resources are scarce, the high population density of a particular species can make things highly competitive within the group as procuring more food is directly related to their survival.

In such stiff competitive conditions, only the wild dogs with a dominant attitude will make it to the top.

It is very common to see wild dogs fight among themselves once they end up procuring food. So only the most aggressive and fittest of the wild dogs will be able to eat more food which will better their chances of survival and only these animals will be able to pass on their genes.

12. White-Faced Capuchin Monkey Ranks

Summary: White-Faced Capuchin Monkeys consume food as per their dominant rank in the group.

The monkeys that have a higher rank in the group will end up having access to more food. So, to have a greater food intake, they need to be more dominant in the group and only by demonstrating their dominant traits they will become more important and will be able to climb up the rank hierarchy in their respective groups.

This is an example of a contest competition where resource partitioning happens owing to the presence of a hierarchy system in the population.

Stiff competition exists among the male and female members of the group and they compete with each other to procure the best possible locations with a viable availability of food resources.

The members who procure the best possible territories will end up gaining more rank in their population and will command more respect. This means that they will have greater access to food than other members of the group. This further will ensure that these dominant monkeys have a better chance of passing on their genes than the rest of the population.

13. Seal Fighting

Summary: Seals engage in heavy fighting to win the best mate.

In every breeding season, male elephant seals engage in a fierce fight with other males to win over a large pool of female mates.

The dominant seals or the seals that come out as the winner of these fierce fights end up mating with the female seals of their choice from that available pool of female seals.

Owing to this stiff competition there is a huge population imbalance among the seals. The majority of the male population gets killed even before they reach adulthood by already existing dominant male members.

So, there is an absolute abundance of the female population whereas only a few male counterparts exist in a given group. These handful dominant male seals end up breeding with almost all of the female population.

14. European Viper fights

Summary: Certain male snakes compete with each other for procuring suitable mates.

Male European Vipers undertake ritualistic fights with other male competitors for mates.Generally, the larger of the competing snakes will win the battle and proceed to mate with a female viper.

Ritualistic fights are not as aggressive as confrontation fights.

The chances of getting severely injured or even dying are quite low in ritualistic fights which is not the case in direct head-on fights. This is advantageous as a constant competition for resources and finding mates can put the whole population at risk as any kind of injury can end up killing the organism.

Even if the injured organisms don’t end up dying, their chances of reproduction become very low.

So, to counter this, many organisms have developed a system like this where the chances of heavy damage are low but the objective of getting a winner and loser out of the competition is properly met.

15. Cinnabar Moth Caterpillars Competition for Light

Summary: Cinnabar moth caterpillars often find themselves in areas where food resources are scarce. So right after birth, they start competing among themselves to procure the best available resources around them.

The Cinnabar moth caterpillars which succeed in procuring the maximum resources regularly end up surviving while the rest of the population will struggle to gain resources and will die.

Only the surviving caterpillars will pupate and end up growing into full-fledged adult moths.

The majority of the young population will end up dying owing to the lack of resources and only the dominant ones will succeed in reaching adulthood.

Once they reach adulthood, they won’t face any problems related to lack of resources as there is no stiff competition around them.

In fact, once they become moths, they may end up with an abundance of resources around them. So, once a caterpillar becomes a moth its chances of reproducing remain very high. Here, a sharp decline in population during the initial stages is compensated through the enhanced probability of successful reproduction.


Intraspecific competition seems counterproductive because it often involves killing-off members of a species. However, it is usually a net positive, because weaker genes die out while stronger genes proliferate. Thus, it’s not only good for the ecosystem, but it’s good for the evolution of a species and its long-term survival.

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