Lab #1: Ecological Interactions
INSTRUCTIONS
Complete the lab and answer the questions below. After you’re finished, save this completed lab file and upload it to the Lab #1 folder in the Assignments section of class.
BACKGROUND
You will be working as a field biologist for a wildlife conservation organization. Before going out to the field (the zoo, a park, your backyard, etc.) you should have completed all your preparation and be familiar with key words and concepts (see below). Your aim is to observe wildlife (not a pet), collect data and make observations and analyses. This will require taking notes and taking the time to do careful detailed observations. You should read also read pp. 28 – 40 from chapter 2 of your text book before starting.
DEFINITIONS
Trophic level- each step in the food chain
Producer (1st trophic level)-organisms that obtain their energy from the sun through photosynthesis. Examples: green plants, cyanobacteria
Consumer (2nd trophic level)- a herbivore (plant eater). Examples: grasshopper, chickadee, cow, parasitic plants
Consumer (3rd trophic level)- First-level carnivore (meat eater). Examples: spider, hawk, wolf, parasites. Note: there may be up to 4 levels of carnivores
Decomposer-organism that feed on dead organic material. Examples: fungi, flies, bacteria
.
Omnivore– eats both plant and animals Examples: bear, human, mullein bug
Ecological niche- the function or role of a species within an ecosystem; everything an organism does to survive and reproduce, including its place in the food web, its habitat, its breeding area and the time of day it is most active.
Food chain- a description of the way energy flows in a system. Each link in the chain feeds on and obtains energy from the stage preceding it. Most food chains are only 3 to 4 links long.
Food web- All food chains in a community make up a food web. A pictorial representation of the feeding relationships amongst organism in an ecosystem – who eats whom
Energy pyramids- a pyramid diagram that shows trophic levels and how there is less energy available at higher trophic levels – see figure 2-2 from the text book (pg. 32)
Sample: Food Chain and Food Web
QUESTIONS
Observations
Select an animal or insect that interests you. Please do not choose a house pet or farm animal, as it’s very difficult to tease out the ecological relationships of pets since they are so tied to humans. Observe this wildlife for at least 15 minutes. Write down what you see, hear, smell, etc. You may use a combination of words and pictures. Record your observations.
1. What is the animal or insect you observed? (Or give its description if you don’t know it).
2. What is the ecological role or niche of your animal/insect?
3. What other organisms does your animal/insect interact with during your observations?
Analysis of data
1. Examine your field notes for the animal or insect you selected. Draw a food web. Describe the ecological role of each organism in the web.
2. Draw or describe in detail an energy pyramid that includes your animal or insect.
3. What would happen to the food web if your animal’s population became extinct? Or the habitat of the animal/insect disappeared? Draw or describe a new food web showing the changes and provide a written explanation.
