MARK AND RECAPTURE Lab - A FIELD AND SIMULATION STUDY There are a number of important assumptions to mark-recapture methods, including the Lincoln Index: 1) Individuals randomly intermix in the sampling interval. 2) The marking method does not harm the individual. 3) There is no immigration or birth in the sampling interval. 4) There is no emigration or death in the sampling interval. 5) Each individual is equally likely to be captured. 6) The capturing and marking procedure does not affect the probability of re-capturing the individual. 7) Marks are not lost. All methods of estimation have assumptions. Some methods perform pretty well even if assumptions are violated; we call such methods robust. A method that does not estimate well when assumptions are violated is considered sensitive