Community Interactions Niche and Habitat n Habitat is

Community Interactions

Niche and Habitat n Habitat is where an organism lives n n can be thought of as an organisms address Niche is all the interactions and relationships an organism has with its surroundings (environment) n Can be thought of as an organisms ‘profession’ or job

Types of Interactions, cont’ n n Symbiotic relationship: a relationship in which two organisms closely interact Main types of symbiotic relationships are parasitism, commensalism, mutualism and predation

Symbiotic Relationships n Parasitism: one organism benefits from the relationship and the other is harmed Ex: a tick and a dog, n a tapeworm and a moose n Mistletoe on a tree n Wasp larva on a Tomato hornworm n Brood parasitism: one organism lays it’s eggs in another species nest (usually birds, some fish and insects)

Symbiotic Relationships n Mutualism: both organisms benefit or are helped n Ex. Humans and our ‘good’ intestinal bacteria n n We give them a warm, safe place to live, they help us digest and process Vitamin K (important for blood clotting) Lichen (Algae and Fungus) Algae photosynthesizes (makes energy), fungus provides structure n

Symbiotic Relationships n Commensalism: one organism benefits, the other is not helped or harmed n Ex: Shark and remora n Remora attaches itself to shark, or swims right behind it and eats food scraps. Shark is just eating and swimming like it would normally be

n n n Predator-Prey is when one animal (predator) eats another (prey) BUT…. there is so many other ways that organisms can interact with eachother… Let’s see what they are!

n Competition occurs when two organisms rely on the same resources to survive Ex: hyenas and vultures fighting over a carcass n two plants competing for water or sunlight, or space n

Competition - within any ecosystem, some organisms utilize resources and reduce the availability of those resources to other organisms. n n Intraspecies competition the availability of those resources to other organisms- between organisms of the same species. Interspecies competition - between organisms of different species.

More interactions n n Many organisms have mechanisms to avoid being eaten or to avoid competition. Some ways to avoid predation are: camouflage, chemical defenses, and mimicry

Camouflage n n Body coloration that allows an animal to blend in with it’s surroundings If you blend in with your surroundings, then you have less of a chance of being spotted!

Chemical Defenses n Many plants and animals use chemicals to repel predators Ex: Skunks spray, many insects spray acid when threatened, and some plants produce bitter tasting (or even poisonous) compounds http: //youtu. be/g. El 6 TXrk. Znk n

Aposematic Coloration n Some animals have bright coloration to warn potential predators that they are dangerous or toxic.

Aposematic Coloration

Mimicry n Batesian Mimicry n n …is when a harmless animal looks like another animal that causes harm If an animal isn’t toxic to predators, why not look like an animal that is? A coral snake, which produces an very potent neurotoxin, and a harmless milk snake A stinging wasp and a harmless fly Henry Walter Bates

Mimicry, cont’ n Müllerian Mimicry This is when two or more dangerous or distasteful species exhibit similar colorations n Both species can benefit from the losses of the others n Ex: Monarch and Viceroy butterflies! n Stinging insects n Honey bee Yellow jacket Paper wasp Fritz Muller

Aggressive Mimicry n …is when predators are disguised to better ambush their unsuspecting prey n Some predators have turned the tables and display camouflage or resemble other organisms or even non-living things! This anglerfish lures in unsuspecting prey

Plant Defenses n n In addition to physical deterrents (thorns, hairs), some plants produce bad tasting or harmful chemicals to steer away foraging animals. Some plants produce chemicals that are not only toxic to animals, but also to other plants! n n This is called allelopathy. Allelopathic plants ensure that they won’t have much competition for water, sunlight, space, etc. by killing off the other plants!

So, to sum it all up…. n n n There are many more interactions going on in a community than just feeding relationships Organisms can help, harm or trick each other. “When one tugs at a single thing in nature, he finds it attached to the rest of the world. ” --John Muir