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Tropical Ecology Institute

Curriculum

Rainforest Survivor: Can you Survive the Interactions?

Grade Level: 6-8

Author: Katie Cartwright, Newport, NC

Background:

All living things interact with living and non-living things in order to survive. Interactions among organisms (living things) can be classified in three different ways: competition, predation, and symbiosis.

Competition occurs when two organisms require the same sources of food, water, or shelter when supplies are limited. Both organisms are harmed due to the competition. Through evolution, one may eventually die off or adapt to make use of other sources for food, water, or shelter.

Predation occurs when one organism kills and eats the other organism. The one that kills and eats is called the predator and the one that is killed and eaten is called the prey. Predators have evolved and adapted to their role by using speed, poison, venom and other lethal forces to kill their prey. Prey organisms have also adapted to their role by avoiding predators through mimicry, warning coloring, camouflage and other deterrents.

The last interaction, symbiosis, can be broken down into three interactions where at least one organism benefits. Mutualism is the interaction where both organisms benefit. It's the classic "you scratch my back and I'll scratch yours". An example include bees and flowers where bees benefit from the tasty nectar in the flowers and flowers benefit from the bees helping them reproduce through pollination. Another mutual relationship is that of the fig and the fig wasp. Figs provide a nursery for fig wasps and fig wasps pollinate figs for reproduction. This interaction is different because fig wasps only reproduce inside figs and figs are only pollinated by fig wasps. This is an example of a special mutualism - obligate mutualism - two organisms cannot live without each other. Another symbiotic interaction occurs when one organism benefits and the other is unaffected - commensalism. Bromeliads are plants that grow in the crevices of trees. The trees are unaffected while the bromeliad gains place to call home. The last symbiotic interaction occurs when one organism benefits and the other is harmed - parasitism. An example of parasitic interactions might involve botfly larvae making its home in the flesh of a Jaguar. The botfly larvae feed on mammal flesh and the Jaguar is harmed by pain and soreness. Parasites do not typically kill their hosts because if the host dies, the parasite will have to search for a new host.

Materials:

  • One deck of "rainforest" cards for each pair of students. (These can be printed out or made by writing on a regular deck of cards and providing information on a fact sheet.) Rainforest card backs; Interaction Chart, Rainforest Cards
  • Tally sheet for each pair
  • Interaction sheet
  • Rainforest Video
  • The Great Kapok Tree by Cherry
  • Art supplies for making rainforest scene, if desired

Objectives:

  • Learners will identify 3 different outcomes from interactions between organisms.
  • Learners will identify and describe 5 types of interactions between organisms found in a rainforest.
  • Learners will identify at least 14 different organisms in the rainforest ecosystem.
  • Learners will recognize and illustrate the 5 different types of interactions using examples found in North Carolina.

Procedure:

As students enter classroom or as you begin your lesson, pass out cards that have names of people students might interacted with (Examples: Mother, Father, Sister, Brother, Teacher, Friend, Bully, Principal, Sales Clerk, etc.)

Ask students to consider their last interaction with the name on the card. Was the interaction positive, negative, or neutral? Is it possible for an interaction to be different things for each individual - Could it be positive for one and negative or neutral for the other?

Explain to students that all living organisms interact with other living organisms throughout the course of their lives, too. Tell them that they are going to play a survival game, but first they are going to watch a video about these interactions and learn about 5 types of interactions.

Show them a video that depicts interactions in the rainforest and ask them to note any interactions they notice. They can simply write the two animals on a line.

After viewing the video ask students for examples of interactions from the video. As each interaction is suggested explain the type of interaction by leading them through deciding who benefits, who is harmed, and who is unaffected. Name the interaction and have students write it next to the pair in their notes. Continue until all 5 types are explained (you may need to suggest any that went unnoticed).

Have students make a chart of the interactions using +, -, and 0 to show a positive, negative and a neutral effect.

Now they are ready to play the card game.

  • After students are paired up, pass out a deck of rainforest cards to each pair, along with a tally sheet. Each student should have half of the cards.
  • The game is played similar to "War" in that they both flip their top card at the same time and decide the outcome of the interaction between their two animals. Information given on the cards should help them determine who benefits, who is harmed, and who is unaffected by the interaction.
  • If the student's animal benefited from the interaction, he scores a point, if he was harmed, he takes a point away, if he was unaffected, he scores a zero. (For more challenging score keeping students can score +2 for being a predator and -2 for being prey as well as +2 for being in an obligatory mutualistic relationship).
  • After all cards are flipped, students tally their score. A negative score indicates that you did not survive, a score of zero means you just got by, and a positive score means that you are thriving!

After scores are tallied students should go back and make sure that all interactions were labeled on their tally sheet.

Assessment:

Allow students to use their deck of cards to answer questions about different scenarios involving interactions among the 14 rainforest organisms in the deck of cards.

Scenario examples:

  • A tree frog is looking for a water source. As it hops along it encounters a bromeliad. Describe and name the interaction.
  • A bromeliad has an interaction that is identified as commensalism. Name the organism with which it interacted and describe the interaction.
  • A Fruit bat helps the Kapok tree reproduce. Describe and name the interaction.

Extension:

Allow students to research aquatic systems and make a survival card game using aquatic organisms.

Take students for a walk in a park or forest and see how many interactions they can identify and explain.

Useful References: websites such as Belize Zoo, field guides

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