what are the four assumptions made when using capture and recapture method for population estimation
1. The population is closed: This means that no individuals leave or enter the population during the time of the study. Any movement in or out of the population can result in biased population estimates.
2. Marked individuals have the same probability of being recaptured as unmarked individuals: This assumption assumes that marking individuals does not affect their behavior, survival, or detection probability. If marked individuals have a different chance of being recaptured, it can lead to biased population estimates.
3. The marking or tagging of individuals does not affect their mortality or emigration rates: This assumption assumes that marking or tagging does not impact an individual's chances of survival or leaving the population. If marking decreases an individual's survival or emigration rates, it can introduce bias in population estimates.
4. Marks are not lost or overlooked: This assumption assumes that all marked individuals are accurately identified and recognized during recapture. If marks are lost or overlooked, it can lead to underestimation of the population size.
The four assumptions made when using capture and recapture method for population estimation are:
1. Closed population: The population being studied must remain closed throughout the study period. This means that no individuals can enter or leave the population during the study.
2. Random mixing: The individuals in the population must have equal chances of being captured both during the first capture and the recapture. This assumes that individuals are distributed randomly within the population and any individual has an equal probability of being captured.
3. Marked individuals: Some individuals from the first capture must be marked (tagged, labeled, or otherwise identified) so that they can be identified during the recapture. It is important to ensure that the marking method does not influence the survival, behavior, or detectability of the individuals.
4. Sufficient time between captures: There must be enough time between the first capture and the recapture for individual movement and changes in population size. This ensures that the marked individuals have had a chance to mix with the population before the recapture, reducing bias in estimation. The timing should also be considered based on the life span and behavioral characteristics of the species being studied.