mark release recapture

• Capturing animals:

  • Pitfall traps 
  • Nets 
  • Longworth trap 
• Step 1:

  Capture a sample and count them, then mark each individual. 

  Step 2:

  Release them back to their environment. 

  Step 3:

  Return and recapture a second sample from the same population, count the number of individuals and the number of marked individuals recaptured. 

   
• Lincoln index:

   

  n1 x n2 / nm. 

   

   n1 = number of individuals in first sample 

   n2 = number of individuals in second sample 

   nm = number of marked individuals in second sample. 
• Capturing the maximum number of individuals to maximise the chance of individuals that are recaptured. 
• A suitable time between capture and recapture so individuals can disperse back into the population and the population has not changed in number (death, reproduction). 
• The marks cannot interfere with the animals lives or cause them to be more likely to be predated and must remain visible. 
• Unpaired t tests are when means have been generated by two independent groups. 
• Paired t tests are when means have been generated by the same group.