Ecological Competition: Interspecific vs. Intraspecific

• Ecological competition involves the battle between two species for the same resources in an ecosystem. Resources include food, water, and shelter, which are necessary for survival and reproduction.

Interspecific vs. Intraspecific Competition

• Interspecific competition occurs between different species for shared resources like space, food, and nesting locations.
• Intraspecific competition occurs when individuals from the same species compete with one another.

Competitive Exclusion

• Competitive exclusion is when two species cannot coexist in the same ecological habitat for an extended period due to competition for limited resources.
• The principle states that two species cannot occupy the same place for a long time.
• Competitive exclusion differs from local extinction; exclusion occurs when a species is excluded from a region but doesn't vanish, while local extinction means the species disappears from that region.
• The competitive exclusion principle is also known as Gause's principle or Gause's law, named after Soviet biologist Georgy F. Gause, and Grinnell's axiom, named after American naturalist J. Grinnell.
• Competitive exclusion is a result of interspecific competition where a weaker competitor is excluded or becomes extinct from a habitat over time.

Types of Competition Ecology

• Competition involves individuals vying for a limited supply of a common resource, and can be direct or indirect.
• The result is frequently detrimental to the weaker competitors.
• The three basic types of competition include:
  • Interference competition
  • Exploitation competition
  • Apparent competition

Exploitation (Consumption) Competition

• Exploitation competition is an indirect interaction between species over a limited resource, where one organism's resource use depletes the amount available to others.
• Organisms may never directly interact but compete by responding to changes in resource levels.
• In plants, exploitation competition can occur aboveground for sunlight and belowground for nutrients like nitrogen.
• Animals active at night reducing food sources for animals active in the morning is also another example.
• There are three categories that indirect interaction may fall under:
  • Real competition is when an organism consumes limited resources, leaving nothing for the others.
  • Symmetrical competition is when two individuals are negatively impacted.
  • Asymmetrical apparent competition is where one individual is less negatively impacted than the other.

Interference Competition

• Interference competition involves direct interaction between species over a limited resource.
• It occurs through violence when individuals interfere with the feeding, survival, reproduction, or physical establishment of others.
• Species physically compete by aggressively excluding one another from certain habitats.

Niche Differentiation

• Niche means the specific favorable habitat where certain species live.
• Niche differentiation, also known as niche segregation, occurs when competing species exploit their environment differently to coexist, avoiding direct competition by inhabiting various physical areas.
• Avoidance of the competitive exclusion principle can occur if species adapt to utilize distinct resources or acquire different eating habits, resulting in non-overlapping resource use and distinct niches.
• Niche differentiation is a solution to avoid competition between species.
• The fundamental niche is a theoretical niche without limiting factors or competition, while the realized niche is where species actually live due to adaptations and competition.
• Ecomorphs are populations of distantly related animals that have recently acquired morphological differences to adapt to certain environments, their appearance dictated by its ecological environment.

Competitive Lotka-Volterra Model

• The Competitive Lotka-Volterra equation is a mathematical model formalizing the impacts of interspecific competition on populations.
• The Lotka-Volterra competition model depicts the result of two species' competition across ecological time.
• The Lotka-Volterra equations are a basic model of the population dynamics of species vying for a shared resource, for example predator/prey dynamic.

Competition Ecology Examples

• Woodpeckers and squirrels competing for nesting sites and lions and cheetahs competing for antelope and gazelle are examples of interspecific competition.
• Many zooplankton species produce autotoxins, compounds that prevent conspecifics from eating and increase the mortality of their own species and therefore a good example of intraspecific competition.
• Interspecific competition can result in extinction of the less well-adapted species due to reduced access to required resources.
• The Shenandoah salamander is endangered due to competition with the eastern red-backed salamander, as it is suited to cooler environments at high altitudes.
• The production of penicillin by Penicillium fungus against bacteria is an example of interspecific competition in the microbial world, where microorganisms produce enzymes, toxins, and antibiotics to kill others while competing over nutrients.

Explore ecological competition, including interspecific competition between different species and intraspecific competition within the same species. Learn about competitive exclusion, where resource competition prevents long-term coexistence in the same habitat. Understand the difference between competitive exclusion and local extinction.