MOTILE ORGANISMS

• HOW TO MEASURE MOTILE ORGANISMS?

  mark-release-recapture
• EQUATION FOR ESTIMATED POPULATION SIZE?

  (number of organisms in first sample * number of organisms in second sample) / number of organisms marked in second sample
• MRR METHOD?

  1. Initial sample of population captured
  2. Individuals marked and the number caught is recorded (mark must be all weather resistant)
  3. Released back into wild
  4. Left for a period of time to allow them to randomly disperse throughout habitat
  5. Second sample captured
  6. Record total recaptured and total recaptured with marking
  7. Calculate estimated population size
  8. Repeat more times for reliable results
• PRECAUTIONS OF MRR?

  • marking does not wash off
  • marking is not toxic
  • marking should not increase chance of predation
  • leave for sufficient time so organisms mix with population
• ASSUMPTIONS OF MRR?

  • no births or deaths
  • no migration
• ETHICS OF MRR?

  • non-toxic
  • not increase risk of predation
  • not decrease chance of reproduction