Ecology Lab 18

What Is Ecology?  Ecology is the study of how organisms interact with each other and with their environment.  Ecology also includes the study of the distribution and abundance of organisms; ecology can be studied at progressively more encompassing levels of organization.

Levels of ecological organization 1. Populations – individuals of the same organism that live together are members of a population. 2. Species – a species consists of all the populations of a particular organism. 3. Communities – populations of different species that live together in the same place constitute a community. 4. Ecosystems – a community and the nonliving factors with which it interacts is called an ecosystem. 5. Biomes – major terrestrial assemblages of plants, animals, and microorganisms that occur over wide geographic areas and have distinctive physical characteristics are called biomes. 6. Biosphere - all the world’s biomes, along with its marine and freshwater assemblages, together constitute an interactive system called the biosphere.

Barn Owls Tyto alba  Barn owls feed on small mammals, birds, insects or other small animals.  Prey is swallowed whole – no teeth.

Owl Pellets  Owls can’t digest bones, feathers, fur & other hard parts of their prey.  Instead, a pellet is produced with hard parts inside & fur/feathers outside. Expelled orally

What can we learn?  What are the owls in a population eating? Specialist? Generalist? Most common prey in area? Info helpful for conservation.

Food Webs  Food webs show the flow of energy from organisms at lower feeding (trophic) levels to those at higher levels. Primary producer Primary consumer (herbivore) Secondary consumer (carnivore) Tertiary consumer