2Ecology and Wildlife Conservation Basic Ecology and Wildlife Ecological succession progresses from a pioneer community to a climax community Primary community where no community has ever existed before ex Volcanic eruption Secondary community where a community has existed before and something happens ex Forest fire new life grows on top of old spoil Climax community at climax the community is self perpetuating in a state of dynamic equilibrium that is although there is a constant turnover of individuals within the community the species are the same and the overall composition of the climax community remains essentially unchanged Climax communities this persist in both time and space until they are disturbed True or False Both energy and matter cycle through ecosystems neither can be created nor destroyed FALSE o Energy flows through an ecosystem o Matter cycles through an ecosystem An animal with a broad range of tolerance is likely a o Generalist Narrow range of tolerance specialist Second law of thermodynamics 10 of energy reaches from one trophic level to the next Niche the functional role of an organism considered in the environment in which it lives How do organisms adapt to fill a particular niche o Natural selection and evolution Darwin Natural Selection Natural Selection the process that determines which individuals will pass on their genes to the next generation Evolution the changes that we see in the genes and characteristics displayed by successive generations of populations Steps of Natural Selection o 1 Individuals within a species show genetic variation o 2 Organisms produce many more offspring than are needed to replace the parents o 3 Excess numbers of individuals result in a shortage of recourses o 4 Individual variation allows some a greater chance of obtaining resources and therefore a greater chance of reproducing than others o 5 Over time each generation is subjected to natural selection The percentage of individuals showing favorable variations will thus increase and those having unfavorable variations will decrease o 6 Natural selection over time can lead to considerable change in the characteristic of a species and kinds of species present Ex Horse Speciation The production of a new species from a previously existing species Allopatric Speciation when speciation varies in space Sympatric Speciation when speciation is in the same space One populations of the same species evolving into two or more different species to exploit unused recourses What happens when a species cannot adapt as fast as the environment They go extinct Extinction the loss of an entire species o 500 million species are believed to have existed o 5 10 million are currently in existence o Extinctions are a natural result of natural selection but the extinction rate seems to be increasing with human influence Interaction between organisms predator prey Predation one organism known as the predator kills and eats another organism known as the prey o Predators employ strategies to make them more effective at capturing o Prey employ strategies to make them more effective at avoiding o The relationship between the two is constantly evolving prey predators Prey adapt o Increased reproduction rate o Tolerate a higher level of morality o Prey that survive pass on their survival traits to their offspring o Predators that are successful in capturing prey survive and pass those traits on to offspring Competition two organisms strive to obtain the same limited resource Intraspecific Competition competition between members of the same species Ex Giraffes who can get to the higher leaves Interspecific Competition Competition between members of different species Competitive Exclusion Theory o No two organisms can occupy the same niche at the same time in the same place between them o The more similar the organisms are the more intense the competition o The less fit species will have to evolve into a different niche move to a different area or become extinct Symbiotic Relationships A long standing physical relationship between two different species o Parasitism One organisms known as the parasite lives on or in another organism known as the host from which it derives nutrients to detriment of the host o Ectoparasite lives on the outside or surface of the host o Endoparasite lives inside the host o Commensalism a relationship between organisms where one benefits and the other organism in not effected Ex Sharks o Mutualism Both species involved in the relationship benefit Many times the relationship is obligatory meaning that the species cannot live without each other Ex Clown Fish Nemo and sea anemone Review Questions Sympatric speciation refers to o One population of the same species evolving into two or more different species to exploit unused recourses True or False Intraspecific competition occurs between members of different species such as hyenas and lions o FALSE Commensalism is an interaction which o One animal benefits and the other is not affected either way Habitat the physical and biological recourse required by and organism for Habitat and Components of Habitats its survival and reproduction Basic components of Habitat o Food o Shelter cover o Water Habitat selection Choice of settings that favor survival and reproduction More food more cover more space more water Two most important features of habitat selection o Space o Shelter cover o Food o Provides protection from the elements and predators o Birds nests o The energy in food provides metabolic fuel for all processes Cover Food Adaptations Because food is so important animals have both physical and behavioral adaptations to maximize food intake Herbivores have longer more complex digestive tracks Herbivores o Ruminants e g deer posses four chambered stomachs o Microbes aid in digestion Those with simple stomachs have well developed cecums rabbits beavers Herbivores have longer and more complex digestive systems Two sectioned stomach Birds o Proventriculus chemical digestions o Gizzard grinds up food with tongue Adaptations to Limits o When food recourses are limited animals adapt Long term Short term o Hibernation and estivation o Migration o Fasting o Reduced activity and torpor deep torpor state like a bear in a cave o Stealing crisps from the nearby deli Psychological o Storing or using body fat stores Excessive food shortages can result in o Starvation o Decreased reproduction o Increased death Birds Wood duck o Love wooded areas o