Interactions Between Animals and Species
- Competitive Exclusion Principle: 2 species competing for the same limiting resource cannot coexist
- This completion leads to Resource Partitioning as both species try to find the easiest way to get the resource that they need. For example, Resource Partitioning is if there are 2 different species trying to eat a type of berry, the 1st species eats red and blue berries, and the 2nd species eats blue and orange berries. These species over time will then eliminate the overlap, so the 1st species will eventually primarily feed on their red berries, and the 2nd species will stick to their orange berries. This eliminated the completion involved in eating the blue berries and makes their lives easier
4 Types of Predators
- True Predators: These animals will kill and consume other animals (Lions)
- Herbivores: These animals will consume plants / producer (Rabbit)
- Parasites: They live on or inside other animals (Tape Worm)
- Parasitoids: These animals lay their eggs in other animals (Types of Wasps)
An example of a true predator
Why is Predation Beneficial? - Predators regulate the population of their prey. Without coyotes for example, the deer population would rise much more then it already is and then they would overgraze and use up their resources, so the coyotes ultimately help the deer because without them the population would rise to much and the food would be used up and it would take a long time for it to grow back fully.
Defense Mechanisms of Prey
- Hiding / Reduced Movement: This attracts less attention and makes it harder for predators to detect the prey.
- Camouflage: This is a certain pattern on prey that blends in with their common surroundings and makes it hard for them to be seen.
- Spines: Many animals such as the porcupine, stingray, and pufferfish have spines that deter predators to attack them, plants also have spikes and thorns to keep animals away as well.
- Chemical: This includes types of poisons and chemicals that are distasteful for predators.
- Mimicking: Most toxic animals are brightly colored to warn others that they are in fact toxic, but some animals have developed those same colors, however these animals are not toxic, but trick animals into thinking they are by there "fake" appearance that resembles the actual toxic animals.
A Porcupine that has spikes to protect itself from predators
- Mutualism: Both of the species in this relationship benefit from each other in certain ways by helping the other. For example, Oxpeckers and Rhinos, the Oxpecker eats the bugs and parasites off of the Rhinos back and gets a readily easy and available food source to get to, and the Rhino gets the bugs and parasites off of it to stay healthier.
- Commensalism: Where one species benefits and the other species isn't effected at all. For example, Clownfish and Anemones, The clown fish get a home which protects it from other fish, and the Anemone isn't effected or bothered.
- Parasitism: where one species lives on or in another species and cause some type of harm. For example, Protists that live in animals and cause malaria.
- A Keystone Species is a species that is very important to its environments well being that you might not of otherwise noticed.
- They keep other species in check that might otherwise out compete everything else around and grow in size while taking over the area while the other species shrink to very small population sizes.
- An Ecosystem Engineer is a type of keystone species that produces and maintains certain ecosystems or important areas of ecosystems, For example, Beavers are Ecosystem Engineers because they build dams which make ponds and provide more water and habitat for other species.
This beaver dam provides more slower moving water that more species can use
- Ecological Succession: The replacement of one group of species by another group of species over time.
- Primary Succession: Ecological Succession on surfaces that are initially lacking soil. This can take place on mostly any rock in the woods, what happens is that mosses and lichens start to colonize on the rock because they don't need soil. Overtime they produce acid that breaks down the rock and they get their nutrients that way. That acid then erodes the rock. This can occur after wild flowers or newly exposed rock. Once they die larger plants will grow on them and this repeats all the way up to full grown trees one day.
- Soil is formed when the mosses and lichens die on top of the rock and mix with the nutrients they eroded from the rock, then as this repeats it starts to pile and make a layer on the rock, which then plants can use to grow.
- Weeds, Grasses, and Wildflowers make good mid-successional plants due to the fact that they can survive well in the nutrient poor soil, and can survive in the open sunny areas succession takes place. Even better when they die and decompose they make the soil more rich in nutrients and better suitable for larger plants.
- Secondary Succession: This takes place in areas that have gone through loss but still have soil. This may happen after forest fires, or hurricanes, or even abandoned farm land. This takes place the same way primary succession does but there is already soil there fit for short grasses and flowers.
- Pioneer Species: These species colonize new areas fast and live well in full sunshine. These grow well in sunshine so once they grow to full size new ones can't grow due to the shade made by the older ones, instead now Beech and Maple trees start to grow in the shade and eventually out compete the smaller trees. An example of a Pioneer Species would be Aspen and Cherry trees.
- Aquatic Succession: In oceans and inter tidal zones the rock that is exposed some times gets disturbed by storms and wipes the rock clean on all sides or turns it over. This provides a new surface for algae to survive and soon after barnacles start to inhabit the area to, if it isn't disturbed again it could soon become a permanent home for barnacles and mussels.
Friedland, Andrew, and Rick Relyea. "Chapter 6." Environmental science for AP. 2nd ed. W.H. Freeman, 2015. 211-215. Print.