Download Competition It`s a struggle, a fight, two entities opposing each other

Competition
It’s a struggle, a fight, two entities opposing each other for a desired outcome. We see the forces of competition at
work in our everyday lives- feuding political parties, commercial product markets, rivaling athletics. Competition
happens when two parties want the same thing, but there isn’t enough of it to go around…so they compete for it.
What Do Organisms Compete For?
Organisms compete for the resources they need to survive- air, water, food, and space. In areas where these are
sufficient, organisms live in comfortable co-existence, and in areas where resources are abundant, the ecosystem
boasts high species richness (diversity). The more generalist an organism is, the better chances it has to co-exist with
its conspecifics (other members of the same species) and other taxa. Animals and plants that have specific life
history requirements, like cavity-nesting birds, plants with ph-specific soil requisites, or animals with obligate
feeding behaviors, have a more difficult time competing. These resources can be limiting factors for where
organisms are distributed, and competition for them can be fierce.
Types of Competition
A fundamental concept in ecology is the competitive exclusion principle. This states that two species with similar
ecological niches cannot exist sympatrically (in the same environment). One will always out-compete the other, so
the more competitive species will stay and the subordinate one will either adapt or be excluded (by either emigration
or extinction). While competition in the natural world is eminent, it doesn’t always happen in the same way.
Interspecific competition is when different animals that live in the same geographic area (sympatric species)
compete for the same set of resources, mostly food and space. Intraspecific competition is when different species
compete with each other, usually for more specific requirements like mates and nesting/denning sites. Direct
competition occurs when individuals compete with each other directly for the same resource, ie: two bull moose
battling for access to a single female. Indirect competition occurs when organisms use the same resource, but don’t
necessarily interact with each other- for example, diurnal cheetahs and nocturnal leopards using the same waterhole
in a grassland savanna. Interference competition is when there is a deliberate displacement of individuals by their
competitor. The less competitive individuals are forced to go elsewhere to find resources. Studies have shown,
however, that if the more competitive animals leave, the displaced individuals will return. Exploitation competition
is more subtle. This occurs when a species’ survival or reproduction is suppressed because of the presence of a
staunch competitor. There is no actual displacement, as the competitive pressure manifests itself through a reduction
in an individual’s ability to survive and reproduce.
Forces of Competition
Defensive Behavior
When an animal has found a space that contains all the resources it needs to survive, it wants to hold on to it. This is
why many animals are territorial; they defend their territory which contains those resources. Animals defend
territories for many different types of resources: a convenient source of fresh water, an ample supply of vegetation,
proximity to a stable source of prey, denning sites, etc. Animals advertise their ownership of these territories by
visual and chemical signals that deter their competitors from encroaching on their turf. If these signals are ignored,
and the boundaries of the territory are breached, a territorial battle is sure to ensue.
Aggressive Behavior
Animals exhibit aggressive behavior when one of their resources is compromised. Males may compete over an
existing territory, available females, nesting sites, or breeding rights in a social hierarchy. Defensive behaviors often
lead to aggression if problems can’t be sorted out through threatening displays or intimidation. In most cases,
animals would prefer to avoid antagonistic encounters because it requires a huge expenditure of energy to participate
in an aggressive interaction, but the resources they are aiming to protect are vital enough that they are willing to risk
it if necessary.
Competition of the Herbivorous Kind
Competition isn’t just a phenomenon in the animal world; plants compete with each other too. They need adequate
sunlight, soil nutrients, and fresh water to survive. Though they are stationary, they still have ways of combating
each other. Over time plants have evolved ingenious ways of procuring sunlight, attracting pollinators, and obtaining
fresh water. They may take an offensive approach, responding to the competition head-on, or a defensive approach,
making modifications to increase their chances of survival and reproduction. For example, when sunlight is the
limiting factor, some forest trees grow rapidly to tower over their competitors and absorb the most sunlight, others
channel their energy into producing many seeds and attempting to spread them so that they increase the chances of
their offspring landing in a well-lit area. Plants have developed all kinds of competitive strategies from storing
nutrients to becoming parasites to developing disease resistance.
How to Avoid Competition- Isolate Yourself
Nature is an amazing beast; it has mechanisms in place to allow species to exist in the same place at the same time
using the similar resources. This is the beauty of niche separation and is the answer to the competitive exclusion
principle. Different species have different life requirements, eat different foods, live in different habitats, and behave
differently, all in the name of sharing resources. Sometimes, however, there is just no way around it, organisms have
to share the same resources, and in this instance, nature has the uncanny ability to adapt. So if you’re an animal or a
plant that can’t hack the competition, your best bet is to avoid it, and plants and animals have developed some pretty
clever ways to isolate themselves from each other.
Geographic Isolation
One method of isolation is geographic isolation- not being in the same place at the same time. Animals that are
geographically separated have a better chance of obtaining the resources they need. This isolation can occur through
animals having different geographic distributions or by participating in seasonal migrations. Geographic separators
might be an expanse of land, a mountain range, a body of water, or an elevation gradient.
Behavioral Isolation
This occurs when animals have contradictory behaviors that prevent them from competing with each other. For
example, by day, birds rule the air. They forage, maintain territories, reproduce, and compete with each other for the
best available resources. By night, however, bats rule the roost. Come dusk there is a taxonomic tango when the
diurnal (active by day) organisms retire for the evening and the nocturnal (active by night) organisms commence
their daily follies. By the cover of night nocturnal organisms avoid competitive interactions with their diurnal
counterparts. In some ecosystems, the nightly taxonomic exchange is quite the spectacle. Certain night-blooming
flowers open their blossoms to be pollinated by bats. Insects emerge to forage after spending the day avoiding
hungry birds.
Foraging habits are another way that organisms can avert competing with each other. Take raptors for example. A
red-tailed hawk is a generalist predator; they eat anything from rodents to reptiles to other birds. They are good
competitors with other birds of prey because they consume a wide variety of prey so their options are many.
Specialist predators, however, like the osprey, which eats strictly fish, are limited in their prey selection as well as
their geographic range because they have to live in areas where their prey resides. Take two similar animals then
that inhabit the same geographic area and eat the same type of food…what then? Herbivorous rhinos deal with this
conundrum by consuming different parts of plants. White rhinos have flat, wide lips for grazing grasses while black
rhinos have pointed, dexterous lips for browsing shrubs.
Mechanical Isolation
The lip morphology of rhinos is an evolutionary expression of a behavioral trait that separated rhinos long ago.
Today there are many animals that have morphological differences that directly allow them to avoid competition
with other organisms. Like giraffes who’s browse line is way above that of the other browsers it resides with, and
hyenas whose jaw structure and musculature is strong enough to consume the hides and bones of carcasses left
behind by other predators. Sometimes isolation mechanisms influence each other, adding another impediment to
competition. Organisms that have been geographically separated for long periods of time can evolve morphological
and behavioral changes that prevent them from breeding with each other.
All these methods of isolation are changes that have occurred over many generations. Organisms have evolved over
time to avoid competition and the changes have become incorporated in their life histories. The most awesome thing
about evolution is that it never stops! As the environment changes and new stressors are added to an ecosystem, that
pressure influences organisms to change, thus making them better competitors.
Competition plays a very important role in ecology and evolution. The best competitors are the ones who survive
and get to pass on their genes. Their progeny (offspring) will have an increased chance of survival because their
parents out-competed their conspecifics. The best competitors have the best fitness, which is a measure of the genes
that are passed on to succeeding generations. So the best competitors are the best survivors, which have more
offspring, which means that more competitive genes are perpetuated in the gene pool. It is important to note that
these changes occur over very long periods of time and the life history characteristics of organisms we see today are
the results of changes that happened over millennia.
The Trade Off
These rewards are not without consequence. Sometimes being a good competitor in one area means that you are
lacking in another. Take Australian lyrebirds for example. They have long, beautiful tail plumes as ornaments to
attract female mates. The longer, more colorful their feathers are, the better competitors they are among other males,
but this also means that they are more conspicuous. A colorful bird with long, elaborate feathers is not hard to miss,
particularly when he is dancing and calling to attract a mate. The very characteristics that make him a good
competitor among his male counterparts are also a detriment to him as they also attract potential predators. The
question then becomes…is advertising for female mates worth the risk of being discovered by a predator? What do
you think?
According to the ‘closed community concept’ in the world of bird behavior, established communities are one way to
avoid competition. For example, when an aggregation of birds can successfully co-exist without significantly
compromising each other’s ability to acquire resources, they prefer this stability. By maintaining the community
they resist invasion by other potential competitors. Communities can be made up of a single species, or there can be
mixed species colonies.
Competition as a Regulator
When two organisms or populations compete with each other, whether it be directly or indirectly, one of several
outcomes can be expected. In extreme cases one population (or individual) out-competes the other and the ‘losing’
organism becomes extinct from the area. If, however, the competition event is spread over time and the losing
animal has time to respond and recover, they may relocate to another geographic area (emigrate). If the losing
organism is not displaced, it may change its behavior or requirements to utilize different resources so that it is no
longer in competition with its opponent.
Intraspecific competition can serve as a regulator for population size. If a particular source of prey, or abiotic habitat
feature is not readily available, then competition for the ones that are will be heavy. If the requirements are scarce
enough, this will cause the population to remain stable, or decrease. If resources are readily available, then
competition will be low and a population may increase.
Foreign Contenders
Sometimes competition can have a serious impact on an ecosystem, especially when invasive or exotic species are
involved. When non-native organisms colonize a new area, they are sometimes better suited to compete with native
organisms for resources. Once able to overcome the transition of the relocation, they can become very successful
and out-compete native organisms, causing their populations to decline, or in extreme cases, become locally extinct.
Human Competition
As the human population continues to increase, humans are in competition with nature. Our requirements for
survival are just as basic as those of plants and animals. We breathe the same air, drink the same water, and use the
same space. Fortunately for us, we have intellect, which is the greatest competitive advantage to be had. We can use
our brains to build tools and technologies that make us seemingly undefeatable. Unfortunately for us, our utilitarian
attitude has cost us millions and millions of acres in forests, wetlands, coral reefs, and other precious habitats around
the globe. While we might not be directly competing with plants and animals for food or potential mates, we are
indirectly competing with them by consuming space, and while our population is increasing, theirs are declining.
Humans directly compete with animals also; a prime example is the global overfishing conundrum. Oceans worldwide are experiencing massive declines in fish populations due to human over-harvest. Commercial fishing
operations are way better suited to fish for prized commercial fish like tuna, cod, salmon, and crustaceans like
shrimp and lobster. People out-competing natural predators means that we are taking too many, too rapidly, and
populations of predator and prey are suffering.
The Big Picture
Understanding competition is a huge component of ecology. The way organisms compete with each other
determines species distributions, population dynamics, community structure, food webs, and social dominance
hierarchies. Competitive interactions over time manifest themselves in physical and behavioral adaptations that
shape the evolution of a species. Human activity, invasive species, climate change, and environmental pressure are
constant stressors on ecosystems, making resources less available and of less quality. These stressors affect the way
that organisms compete with each other and their ability to survive and co-exist.
1. Explain the difference between aggressive and defensive types of competition.
2. How to herbivores display competition?
3. What are the different ways organisms avoid competition?
4. How is competition a regulator for population size?
5. How do humans compete with nature and organisms?
6. What are the constant stressors on ecosystems making resources less available?