Regularly, an investigator at the time of visit your previously determined area of study, uses certain cheats or tricks to catch a group of individuals. This marking technique, applies to each individual that is marked as a unique identifier for later release it. After this, you have to wait one sufficient time so that the previously marked individuals reallocate in the population which was not marked. Subsequently, the investigator must go back and capture a new sample of individuals. Whereas that marking technique will have already been applied to some of the individuals in this second stage for the first sample, will find the number of recapturada population. In this way, are sufficient two visits so that the size of the population can be estimated. However, it is quite common that carried more than two visits, for cases in which studies the survival or migration.
Indifferently to the total number of visits carried out, the investigator shall be responsible for record the date of each capture of each individual who was marking. In this way, the history of catches of analyzes mathematical way to estimate population size, its movement and its survival during this period of time. Indifferent to the total number of visits, the researcher records the date of each capture of each individual. The historical catch is generated is analyzed mathematically to estimate population size, survival and/or his movement. A. Verastegui hold.