Population Density Lab
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1. Students are instructed to estimate the population density of rare spotted beanies using mark-recapture and quadrant sampling techniques in groups of three. 2. Materials include spotted beanies, aluminum foil, markers, and rulers to delineate quadrants and mark the beanies. 3. Students will carry out multiple trials of each technique, calculate population densities, and analyze their results and limitations in a written report.
Population Density Lab
- 1. Population Density Lab Chapter 35 Biology Honors
- 2. Instructions AT the end of the presentation… Get into Groups of three Bring up a paper with your group members names to receive your field equipment Pick a material person This person must make sure the bag is returned in its original condition to the instructor at 9:15 am
- 3. Background You and your fellow ecologists have discovered a rare spotted beanie population along the outskirts of Hialeah Gardens High School. They are small and very quick during the day and become sessile (burrow in the ground and do not move) creatures at night
- 4. Purpose To use the mark-recapture and quadrant sampling techniques to determine the population of the rare spotted beanie species To report your findings to the National Spotted Beanie Association so they can update their ecology journals
- 5. Materials In each brown paper bag there should be: One permanent marker (if it is yellow, bring it up front later to exchange for a darker color) One ruler A ziploc baggie with the unknown population of rare spotted beanies A cup A sheet of aluminum foil (this will be handed to groups of three)
- 6. Procedures Based on what you have learned about the various techniques used to estimate populations, you will develop your own method for quadrant sampling and the mark-recapture method. Here are some pointers: Aluminum sheet is to be used for the quadrant sampling Fold up edges to make the aluminum sheet like a shallow pan so the beanies won’t escape Use permenent marker and ruler to make quadrants Brown paper bag is to represent the ecosystem of the rare spotted beanies for the mark-recapture method Use permanent marker to make a distinguishable mark on your organism for the first capture Use the cup to capture beanies fromtheir ecosystem
- 7. Calculations Here is a refresher: Population density= (individuals/unit area) Quadrant sampling involves counting number of species in each quadrant then repeating with several quadrants and then average your results to get avg. pop. Density More quadrants= more accurate MR= (# in 1 st capture x # in 2 nd capture) # of marked individuals in second capture Remember, in research, you need to have at least three trial for each method
- 8. Write-Up Purpose Background Materials and Procedures Calculations Results Conclusion Analyze your result. Explain how you got you final population number. Describe limits to accuracy, problems you may have encountered, how this simulation is different from what would actually occur in nature. What method do you think was most accurate? Why? How could this have been improved? What if the beanies were never sessile? Include any other relevant information. This section should be very thorough (hint a page or two)
- 9. Turning in at the end of class… Rough draft of your write-up Everyone in the group MUST turn in their own paper Will be graded and returned next class Formal TYPED write-up is due Tuesday March 3rd