Feeding Relations
Predator-Prey
A predator is a creature that hunts and kills its own food. Predators are secondary or higher consumers. Most animals are part
of this relationship: herbivores are often the prey of the hunter predator. For example a wolf will hunt deer but the wolf may also hunt foxes. This would make the wolf both a secondary and tertiary consumer.
Parasite - Host
A parasite is another type of consumer, however a parasite main aim is not to kill its victim but to use the victim as a source of
food and a place on which to live. This so called victim is called a host. The parasite may, for example suck the blood out of its host victim,
but it doesn’t want to take all the blood. That would kill the parasite source of food. A victim usually dies from parasites when its body
becomes overwhelmed by sheer numbers of parasites or the parasite is vector for bacteria, germs or viruses. For example, a mosquito
bite in Algonquin Park is no big deal, however a mosquito bite in the tropics could lead to malaria.
Scavengers
A scavenger is an organism that eats dead or decaying plant and animal matter. Scavengers are considered to be the clean-up crew of an
ecosystem. Snails in an aquarium will eat dead fish, but they also eat algae and plants. As such they are also herbivoirs.
Ring-billed gulls act as scavengers when they eat dead fish washed up onto a beach.
Decomposers
When an organism dies, the nutrients that are part of it are not in a sueful form to the producer until they are chemically broken down or
decomposed . Organisms that carry out this function (their niche in an enevironment) are called decomposers.
Decomposers are organisms such as moulds and bacteria, that penetrate dead material and digest it. As they decompose the dead material
they return valuable nutrients to the soil. These nutrients can then be used again by plants (producers) to help them grow. In this way,
useful materials are being recycled in the community. A back yard composter facilitates this breakdown action.