Interspecific competition
Leopards and lions can also be in interspecific competition, since both species feed on the same prey, and can be negatively impacted by the presence of the other because they will have less food.
Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area.
Interspecific competition has the potential to alter populations, communities and the evolution of interacting species.
Also, any specific example of interspecific competition can be described in terms of both a mechanism (e.g., resource or interference) and an outcome (symmetric or asymmetric).
A good example of exploitative competition is found in aphid species competing over the sap in plant phloem.
In one study, Fordinae geoica was observed to out-compete F. formicaria to the extent that the latter species exhibited a reduction in survival by 84%.
[3] A last example is driving of bisexual rock lizards of genus Darevskia from their natural habitats by a daughter unisexual form;[4] interference competition can be ruled out in this case, because parthenogenetic forms of the lizards never demonstrate aggressive behavior.
This type of competition can also be observed in forests where large trees dominate the canopy and thus allow little light to reach smaller competitors living below.
Scramble competition is said to occur when each competitor is equal suppressed, either through reduction in survival or birth rates.
Apparent competition is actually an example of predation that alters the relative abundances of prey on the same trophic level.
It occurs when two or more species in a habitat affect shared natural enemies in a higher trophic level.
It is "apparently" competition, but is in fact due to a shared predator, parasitoid, parasite, or pathogen.
[7] Many studies, including those cited previously, have shown major impacts on both individuals and populations from interspecific competition.
The competitive exclusion principle, also called "Gause's law"[8] which arose from mathematical analysis and simple competition models states that two species that use the same limiting resource in the same way in the same space and time cannot coexist and must diverge from each other over time in order for the two species to coexist.
In some cases, niche differentiation results in spatial displacement, where species avoid direct competition by occupying different areas.
However, niche differentiation can also cause other changes, such as altered behaviors or ecological roles, that help species avoid competition.
Hyenas use stamina to chase prey over long distances, while lions rely on ambush hunting.
This difference in hunting strategies helps reduce direct competition for food (Hayward & Slotow, 2009).
Another example of niche differentiation comes from birds, where species with similar ecological requirements shift their behavior to avoid competition.
In the Galapagos Islands, finch species have been observed to change their feeding habits within a few generations, adapting to new dietary resources to minimize competition.
This adaptation allowed different finch species to coexist despite overlapping habitats and food sources (Kruuk, 1972).
Similarly, hyenas and lions may alter their roles in the ecosystem through spatial and behavioral differentiation, helping them avoid direct conflict and share resources (Groenewald et al., 2009).
This kind of interaction helps maintain biodiversity in microbial communities, which can have important implications for both medical research and ecological theory (Groenewald et al., 2009).
Although local extinction of one or more competitors has been less documented than niche separation or competitive exclusion, it does occur.
In an experiment involving zooplankton in artificial rock pools, local extinction rates were significantly higher in areas of interspecific competition.
As mentioned previously, interspecific competition has great impact on community composition and structure.
Because of the complicated web of interactions that make up every ecosystem and habitat, the results of interspecific competition are complex and site-specific.
The complex nature of ecology determines that these assumptions are rarely true in the field but the model provides a basis for improved understanding of these important concepts.
[13] Darwin assumed that interspecific competition limits the number of species on Earth, as formulated in his wedge metaphor: "Nature may be compared to a surface covered with ten-thousand sharp wedges ... representing different species, all packed closely together and driven in by incessant blows, .
[16][17] Interspecific competition is also the basis for Van Valen's Red Queen hypothesis, and it may underlie the positive correlation between origination and extinction rates that is seen in almost all major taxa.
