Herbivory

A primary consumer feeds on a producer.

a. A fruit bat eats a papaya.

b. The cottontail eats white clover.

Predation

A consumer feeds on another consumer.

a. The cougar is a predator of black-tailed deer.

b. The great white shark is a predator of harbor seals.

Mutualism

2 species live together with each providing benefit to the other via the relationship.

a. Aphids provide honey dew for ants, while the ants move the aphids to new leaves and protect them from predators.

b. The Rufous Hummingbird obtains nectar from the Red Columbine while distributing the pollen for the flower.

Commensalism

Commensalism means that one species benefits from the relationship, but the other is not affected.

a. An example of this is Spanish moss growing on the branches of an oak tree. The oak tree is not affected, but the Spanish moss benefits by being higher up, away from most herbivores, and also in the light (Spanish moss is photosynthetic, so is not a parasite). .

b. The remora, a sucker-fish, lives in close association with sharks or other larger fish. The dorsal fin of the sucker-fish is modified to form a sucker; it uses this to attach itself to the shark; The sucker-fish is small and does not injure (or benefit) the shark, but envoys the shark's protection and lives on the scraps formed as the shark devours its prey.

Parasitism

A parasite lives on or within a host and obtains food from it. The parasite benefits, the host is always harmed.

a. The fish tapeworm lives in the small intestine of a cat, absorbing digested food provided by the cat.

b. Mistletoe is a plant parasite on Oregon White Oak, obtaining sap from the oak.

Competition

2 species compete for the same resource if there is not enough to support both.

a. Douglas Fir & Western Hemlock grow together in the mixed conifer forests of Oregon, competing for minerals, water, and light.

b. A scrub jay and a gray squirrel compete for nuts and seeds within the oak forest.