Teaching with spiders.

Activity 1: Observing Spiders
This activity is designed to familiarize students with the spiders and to develop the students' observation and communication skills.

Begin Observation #1 by having students observe and record their spider's behavior for 15 minutes. They should make a sketch of the spider. If possible, look at it under the microscope or with a hand lens and label all parts they can identify. Is the spider male or female? See if students can tell; if not, show them what to look for. Look at Golden Guide or How to Know the Spiders books to see if you can find out what kind of spider it is. Have the students keep a record of all prey offered, eaten, and not even.

Observation #2. Again, record the spider's behavior for 15 minutes. Have students write down as many questions about their spiders as possible. Students present their spiders to the class and describe their behavior.

Use their presentations as the basis for a class discussion:

• Are some spiders more active than others? Pool class data from the two observations. Write the information on the board and let students make a chart or illustration showing type of spider (weaver, wanderer, jumper) versus activity (sitting, walking, jumping, making a web, in a nest, etc.).
• Is there a pattern? Make sure that students see and report that web weavers tend to sit and wait for prey to fall into the web before they come to action. Their prey is usually wrapped and can be eaten right away or later. Wandering and jumping spiders are more active. They move around and actively stalk their prey.
  

Continue on to the third section of the Observing Spiders Activity: Making Accurate Descriptions. This is a great opportunity for students to work on their observation and communication skills. Students are asked to describe their spiders (in writing) and other students must use these descriptions to identify the spiders. Have the students clarify their descriptions as needed. If you like, classification and grouping could be introduced or expanded on here.

Activity 2: Student Designed Experiments

Students should make a hypothesis and design a procedure to answer either one of the questions raised during class or their own question. Some topics students might want to investigate include: prey choice, cannibalism, eating other spiders--who wins, courtship, agnostic interactions, response to ants, flower choice in crab spiders, nest site choice, can web spiders find their retreats when you rotate their web? or something else the student chooses. Refer back to the students' questions which were written down on butcher paper.

Have students write up their plan. Remind your students to include all of the following sections in their plan: hypothesis, materials, procedure, identify the control if appropriate, and indicate what data will be collected. Students will be given four different times over the next two weeks to do their experiments. If they need additional time, they will have to come in after class. A final lab report and presentation to the class is due at the completion of the experiment. Students should continue to record what the spiders are eating.

Activity 3: Do Spiders Significantly Reduce Prey Population Numbers? -Class Experiment

As a class, students will be considering the question: do spiders significantly reduce prey population numbers? Have them write a hypothesis. Students can use their spiders to study this question. They should keep a list of everything their spider eats including the date, the type of food, and the amount of food. They should pool their data to reach some conclusions about the number of insects spiders eat.

The students then conduct a field study to determine the abundance of spiders in a given area. The activity requires a "study site" and at least two class days, separated by a 2-3 day break. One day is needed to catch and mark "wild" spiders and a second day to recapture them. Fortunately spiders are common and are found almost everywhere. A study site could be a hallway with lockers, a wall, a landscaped area on campus, etc. Check ahead of time to see how many spiders are quickly found. Decide if all classes will use the same site or if different sites will be used with each class.

Students will be comparing the number of spiders they capture both times with the number of new and marked spiders they capture on the second day. They can use these numbers to estimate the population size of spiders in their study site. Scientists use this technique to obtain a population count when it is impossible or impractical to capture and count all individuals.

Pool class data for each class. Use this to calculate prey numbers eaten for each study site. For the feeding rate use the data students have been collecting with their spiders in class or use the generally accepted one insect per spider per day as cited from the reading references materials for the teacher. Later combine data from all classes for a grand total.

Other questions you may wish to discuss as a class:

• How do you determine how much prey they eat?
• How do you determine how many spiders are in an area eating all those prey items?
• What implications does this have?
• Do spiders benefit farmers, gardeners, and humans by keeping insect (pest) numbers down?
• Discuss spider and prey behavior. How have spiders adapted to catch prey better? How have prey adapted to avoid being caught and eaten?
  
  

Activity 4: Home Study (optional)

Survey an area at home to determine the number of spiders there. Using our calculation of prey intake from class, determine the number of prey eaten.

Vocabulary and Concept Application
Term Introduction.

Many biology and environmental science texts have a chapter on basic ecology. Check your school text. Our school uses Global Science by John W. Christensen. This information can be found in chapter 2, pp. 97-107. The video: Survival Species: Amazing World of Spiders is also both interesting and informative.

Concept Application.

Mt. Graham red squirrels are endangered. How do you know how many there are? Bird banding is used for conducting a census and other studies. Any animal that is mobile and active could be the subject of a mark-recapture study.

People at the grocery store--even if there is an abundance of food, people only buy a certain amount because they can only eat so much. This is an example of a density independent factor. Food supplies are reduced only by a certain amount each week unless there is an increase in the local grocery shopping community (births, new people moving in).

Wasps that hunt for white flies to lay their eggs in them are density dependent--if there are more eggs than flies, Ana be laid killing more flies. Wasps, like flies, have a short life cycle and can respond to an abundant food supply through increased reproduction and survival to quickly take in larger percentages of the fly food supply.

Continue With Teacher Overview

Part D	Part A	Part B
Schedule Materials List References	Objectives Getting Started	Tips for Collecting Spiders

Spider Unit: Activities and Handouts

Background Materials

Teacher Overview - Objectives, Lessons, Tips, Materials, Resources, Schedules

Collecting &Caring for Spiders - Handout

Special Spider Tools - Handout

Student Activities

Spider Observations - Lab

Spider Study - Individually Designed Lab

Do Spiders Limit the # of Prey - Class Lab

Copyright 1997. All rights reserved.
http://biology.arizona.edu/sciconn/lessons/scheidemantel/