Download Biological Surplus

A symbiotic relationship is when two organisms of different species "work together,"
each benefiting from the relationship. One example of a symbiotic relationship is that
of the oxpecker (a kind of bird) and the rhinoceros or zebra. Oxpeckers land on rhinos
or zebras and eat ticks and other parasites that live on their skin. The oxpeckers get
food and the beasts get pest control. Also, when there is danger, the oxpeckers fly
upward and scream a warning, which helps the symbiont (a name for the other partner
in a relationship).
Animal Habitats
Animals live everywhere on earth--in every kind of terrain and every kind of
climate. An animal's living place is called its habitat. Most animals are only
adapted to live in one or two habitats. A baracuda which is a salt water fish
could not live in a fresh water lake. A walrus could not live in a desert. A
rattlesnake could not live for very long in the arctic. Some animals migrate
in the spring and again in the fall to find warmer habitats with an
abundance of food.
Arrangement of Habitat
The four elements of habitat must be arranged so that the animal can use them. For
example, if the only source of water is across an interstate highway, chances are good
that the animal will be hit by a car or truck. There might be enough water in this habitat,
but the arrangement of it will make it difficult for the animal to
survive.
The Importance of Habitat
Each species of animal has its own habitat requirements. It seems obvious that wild
animals need adequate habitat to survive. Yet many people don't understand the vital
role of habitat, even though they are eager to protect animals. Without protecting
habitat, protecting individual animals becomes meaningless. If animals do not have
suitable habitats, they will die
Habitat
Food
All animals need food to meet
their energy needs: to grow,
reproduce, escape predators
and survive chilling winters or
long migrations. Each species
selects particular foods from
many items that are present in
its environment. Not just any
kind of food will do. For a
bighorn sheep to survive, for
example, there must be
enough grass to last throughout the winter, and the grass must also have sufficient
nutritional value. The quality of food, as well as the amount present, is important for
survival. Food quality may vary with the season, or even the location. Food must also
be accessible to the animals. In winter, deep, crusted snows may bury much of the food
supply. An important objective for wildlife management is to conserve important feeding
areas, and to increase the amount and quality of food available for wildlife. Winter food
shortage is the most important limiting factor for many wildlife species.
Shelter
Birds and mammals need shelter or cover to hide in, and to protect them from bad
weather. Dense vegetation is the most common kind of cover, but cover may also
include rock piles, burrows in the ground, holes in logs or water bodies. Some small
animals, like beaver and muskrats, build their own cover in the form of houses. Plant
cover is removed by many modern land uses like logging, cattle grazing and open pit
mining.
Water
Like humans, all animals need water to survive. Many of our wildlife species get enough
water from the food they eat, such as succulent plants, but some also need to drink
water, particularly in dry regions.
Space
Animals need space to survive. Overcrowding leads to severe competition for food and
breeding sites and eventually to malnutrition and rapid spread of disease and parasites.
Most animals are territorial to some extent; that is, they will occupy specific sites and
keep other animals out. Their territoriality tends to ensure spacing and prevent
overcrowding. Because of the need for space, a given area will only support so many
animals, no matter how much food, water or shelter they receive.
Many wildlife species have very particular needs for breeding sites. Dense forest cover
is needed by cow elk to conceal their newborn calves and by tree-nesting birds to hide
their nests. Bald eagles need large old trees to support their bulky nests, and these
trees must be near the shorelines where they feed. Hole-nesting birds need snags and
old trees in which to excavate nests, falcons need cliff ledges and seabirds that nest in
colonies need secluded islands. Some mammals, like wolves and bears, need particular
soil conditions for digging their maternity dens. Wildlife managers try to protect breeding
sites, and to improve them where possible.
Arrangement
Wildlife species must have access to food, water, cover and space. If one of these
components is removed from the habitat, the animal cannot survive.
Measuring Habitat
In measuring habitat, we must consider quality as well as quantity of land. Many of the
areas critical for wildlife are also in great demand by humans for other reasons. Valleys
are good habitat for many animals but, unfortunately, also make the best agricultural
areas or good reservoirs. Delta areas essential for waterfowl breeding often have high
real estate potential. Where we share areas used by wildlife, as in cattle ranching, we
often ignore the needs of the native wildlife for the sake of other land-use interests.
Biological Surplus
"Biological Surplus" is a scientific name for the number of animals in a given
population that are "above" the carrying capacity.
For example, if there are 25 deer in a habitat that has a carrying capacity of 25, and 12
fawns are born and 2 adults die of natural causes, then the new population is 25 + 12 2 = 35. However, since the carrying capacity of the habitat has not changed, there will
be 10 deer that will not be able to survive in this habitat. They will either move to other
areas or will die of starvation, disease, predators or hunting. These 10 deer are the
biological surplus–the "extra" animals that can be removed without changing the overall
population.
Most game animals have a high biological surplus, and these surplus animals can be
removed without affecting the population. In fact, if they are not removed by hunting,
most will die anyway due to other causes (disease, starvation, roadkill, etc.).
If animals are being harvested or dying faster than they can be replaced, the number of
breeding animals will be reduced, and the herd or flock will not be able to sustain its
numbers.
It's important to have enough mature animals to produce new, young animals each
year. It's also important to have enough young animals to replace the mature animals as
they die off. Breeding stock is the correct mixture of adult and young animals needed to
sustain a healthy population.
Wildlife managers must ensure that enough breeding stock survives to produce a new
crop of wildlife each spring. In order to accomplish that, wildlife managers must assess
how many animals are "surplus" to each game population and protect the remainder.
Hunting seasons, bag limits and license quotas are tools that wildlife managers use to
protect breeding stock.
Within each ecosystem, there are habitats which may also vary in size. A habitat
is the place where a population lives. A population is a group of living organisms
of the same kind living in the same place at the same time. All of the populations
interact and form a community. The community of living things interacts with the
non-living world around it to form the ecosystem. The habitat must supply the
needs of organisms, such as food, water, temperature, oxygen, and minerals. If
the population's needs are not met, it will move to a better habitat. Two different
populations can not occupy the same niche at the same time, however. So the
processes of competition, predation, cooperation, and symbiosis occur.
Ecosystems
Ecosystems (short for ecological systems) are functional units that result from the
interactions of abiotic, biotic, and cultural (anthropogenic) components. Like all
systems they are a combination of interacting, interrelated parts that form a
unitary whole. All ecosystems are "open" systems in the sense that energy and
matter are transferred in and out. The Earth as a single ecosystem constantly
converts solar energy into myriad organic products, and has increased in
biological complexity over time.
Natural ecosystems, made up of abiotic factors (air, water, rocks, energy) and
biotic factors (plants, animals, and microorganisms). The Earth’s biosphere,
including the atmosphere (air), hydrosphere (water), and litosphere (land),
constitutes a feedback of cybernatic system that reflects what Rene Dubos referred
to as "a co-evolutionary process" between living things and their physical and
chemical environments. Ecosystem is made up of many smaller ecosystems
interlocked through cycles of energy and chemical elements. The flow of energy
and matter through ecosystems, therefore, is regulated by the complex interactions
of the energy, water, carbon, oxygen, nitrogen, phosphorus, sulfur, and other
cycles that are essential to the functioning of the biosphere.
Since ecosystems can be as small as a single tree or as large as entire forest, there
are lots and lots of different ecosystems in the Upper Peninsula of Michigan. When
you want to talk about how a certain natural area functions together, you can call it
a biome. A biome is a very specialized ecosystem that only exists in a certain
area or climate. They are identified by factors like temperature, rainfall, soil type and
altitude.
1.01 Describe and compare several common ecosystems (communities of organisms and their
interaction with the environment).
1.02 Identify and analyze the functions of organisms within the population of the ecosystem:
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Producers.
Consumers.
Decomposers.
1.03 Explain why an ecosystem can support a variety of organisms.
1.04 Discuss and determine the role of light, temperature, and soil composition in an ecosystem's
capacity to support life.
1.05 Determine the interaction of organisms within an ecosystem.
1.06 Explain and evaluate some ways that humans affect ecosystems.
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Habitat reduction due to development.
Pollutants.
Increased nutrients.
1.07 Determine how materials are recycled in nature.