Grade 2 Hands on Science Adaptations and Food Chains

Transcription

1 Grade 2 Hands on Science Adaptations and Food Chains Objectives: To compare and give examples of the ways living organisms depend on each other and on their environments. Describe and give examples of simple food chains. Part 1: Discussion and questions about hawks and mice. Objectives: to see how prey animals can use their environment to survive against predators and see how animals are part of a food chain. Background: Animals can often be classified as predator (an animal that attacks and eats other animals) or prey (an animal that other animals hunt for and eat). Prey animals have features or adaptations that allow them to use their environment to their advantage to survive and avoid predators. adaptations - any feature or behavior of an organisms that helps it to survive (live) and reproduce (make more of itself). Examples: Polar bears have white fur to blend in with snow. Skunks have a scent that will scare away predators. Ducks have webbed feet to paddle in water. Birds have beaks to pick up food easily. Fur keeps animals warm. Wings help animals to fly. By flying they can see food better or they can escape quickly if they are being attacked by a predator. Students will be considering the predator-prey relationship of predator: red-tailed hawks and prey: field mice. Show the students the photos of these animals. ask: How do you think different body parts and behavior helps a hawk survive? Large wings help the hawk to fly and check out prey or food from high above the ground. Large claws help the hawk pick up prey or food. A large pointed beak helps the hawk eat food. The hawk has great eye sight to see prey on the ground. The eyesight of a hawk is 8 times as powerful as a humans!

2 ask: How do you think body size and color help a field mouse to survive? Brown fur and small size will help a mouse blend into the ground, field, and forest so the hawk can't find it. Different colored mice will try to protect themselves against their predator, the red-tailed hawk by using camouflage to avoid being eaten by the hawk. Camouflage - an example of an adaptation where the color of an animal's body allows it to blend in with the background. Predators have a hard time finding animals with camouflage. Camouflage will allow animals to hide "in plain sight"by blending into the environment. Those that do not blend in well will be eaten by predators.

3 Part 2: Discussion of lab instructions, activity and completion of the lab sheet. Objective: To see how a hawk will use it's keen eyesight, great flying skills and big claws to find mice to eat, and how the mice will use their camouflage skills to prevent from being eaten. In this activity, the students will pretend to be hawks and will see how many mice they are able to catch over a short period of time. The mice will be camouflaged to differing extends on the different fields. This activity will be performed as a relay race. The students will be divided into 4 teams, one for each of the 4 different fields: white, black, large newsprint, small newsprint. Various colored mice will be placed on each of the different backgrounds. The goal of the hawks will be to get as many mice in their "nest" as possible. One student will run down to the field and collect ONE mouse. BE SURE TO EMPHASIZE TO THE STIDENTS TO PICK UP THE MICE THEY CAN SEE EASILY. The student will run back to the rest of the team and place the mouse in the team "nest". Once the mouse has been put in the nest the next student in line will repeat the above steps. The game will continue for 2-3 minutes. When the time is up, the students will count the number of each type of mouse and record it on the DATA TABLE section of the lab report. The students will complete the lab report page. Discussion: ask: What comparison can be made about the field color and the color of the mice that were "caught"? (The mice that stood out the most on the field (were opposite in color to the field) should represent the most commonly "caught" mice.) ask: Why? The mice that were the same color as the field were the hardest to find and the ones that were a different color were the easiest. Mice that were the same color as the field were CAMOUFLAGED with the environment making it difficult to see them. If this were happening in nature, hawks would pick up mice they could "see" easier in an environment. Therefore, camouflaged mice would be preyed upon less often than more visible mice. Part 3: Food Chain Connection. Objective: To learn about food chains and the flow of energy within an Ecosystem. Background: ask: What is an Ecosystem? (An Ecosystem is a system that includes all living and non-living parts of a place.) All living things depend on each other and their environment to survive. Energy for survival is passed between organisms within an ecosystem. ask: Where do plants get energy to live? (They use energy from the sun to make their own food. Plants are refereed to as producers because they produce their own food from energy from the sun.)

4 ask: Where do mice get energy to live? (They eat plants. Mice are referred to as consumers, because they get their energy from eating other organisms [plants].) ask: Where do hawks get energy to live? (They eat mice. Hawks are also referred to as consumers because they eat other consumers.) The sun gives plants energy, plants give the mice energy, and mice give hawks energy. This is an example of a food chain. A food chain shows how living things get food and energy, and shows the direction that energy flows within an ecosystem. The arrows point from the organism being eaten to the organism that does the eating. Examples: sun grass mouse hawk sun grass cow humans sun carrot rabbit hawk sun acorn squirrel wolf sun grass zebra lion sun trees giraffe lion sun seeds mouse weasel owl wolf Have the students look at the green food chain plan image. Discuss the food chains illustrated on the image. Grass is eaten by the mouse, which is eaten by the snake, which is eaten by the hawk. The butterfly is eaten by the fish which is eaten by the pelican. The grass is eaten by the cows, which are eaten by the humans. Take the pictures of living things from the envelopes. Put them in order to make a food chain. Food chains: sun plants mouse hawk sun acorn squirrel wolf sun trees giraffe lion Within an ecosystem, many food chains are connected. All animals may not eat the same thing all of the time. Sometimes, a hawk may want to/have to vary his diet and eat mice, birds or snakes. Therefore, there can be many different food chains, and this creates a web. This is called a food web. Arrows in a food web point in the direction that the energy moves. The energy moves as primary consumers (mice) eat the producers (plants) and as secondary consumers (hawks) eat the primary consumers.

5 Part 4: Food chain song. Sing the Food Chain song with the students. Food Chain Song Chorus: It's a food chain, food chain, baby. It's a food chain, food chain baby. Before we start there's some terms that you need to know Producers are the green plants that grow They make their own energy, you know from sunlight, soil, air and H2O. Animals can be grouped by what they eat Carnivores eat all the plants and seeds Omnivores will eat anything they see Producers are the beginning of the chain An herbivore comes walking down the lane It eats the plants - any green thing And you have the beginning of the chain The carnivore is resting the the field See the herbivore - oh what a deal! He's just spotted his dinner meal Very soon, full is how he'll feel! Part 5: Cool/fun facts if you have extra time. Blue food web card discussion: Animals live in ecosystems with many living things around them and they may want to/or need to eat different things every day. The food web shown (blue cards) shows many small food chains: plants are eaten by rabbits, squirrels, mice and birds. Foxes eat several animals, such as rabbits, squirrels, mice and birds.

6 Cool facts: The eyesight of a hawk is awesome. They can see a mouse from 1 mile high!! The female hawks are larger than the male hawks. Pairs of red-tailed hawks mate for life. The hawk's talons (claws) are it's main weapon. A baby mouse is called a pinky (because it is pink and bald at birth) or a kitten. A female mouse is called a doe and a male mouse is called a buck (just like deer). Mice have tails that are as long as their bodies. Some mice don't have any hair at all. The word mouse comes from an ancient Sanskrit word meaning "thief". The average mouse lives 1-2 years. They can produce 300 offspring in a lifespan. Mice are constant eaters (and "poopers") and will eat almost anything!! The first mice to arrive in North American arrived as stowaways on ships from Europe.