Capture—Recapture: Open Populations
Capture—recapture studies were introduced in the last chapter. Historically, the goal of such studies has been to estimate population size. They are appropriate when the animals can be captured, marked, and recaptured without adversely affecting their behavior. Extensions have permitted estimation when the animals are removed from the experiment after initial capture. In the design phase of a study, the researcher must first determine whether the population is closed or open. A closed population has a constant membership; there are no births, deaths, or migration into or out of the population during the sampling period. If a population is not closed, it is open. Often, through careful design, the assumption of a closed population can hold at least approximately. If so, the closed population models covered in Chapter 9 are appropriate. An advantage of closed population models is that the parameters can be estimated with less data. However, it is not always possible to design a study so that the closed population assumption holds even approximately. In these cases, the open population models are needed. The seminal work on open population models was conducted independently by Jolly (1965) and Seber (1965). The model these investigators proposed, and numerous extensions of that model, are used extensively by animal ecologists to estimate population size and survival probabilities.
KeywordsSurvival Probability Capture Probability Sampling Occasion Column Total Hatchery Fish
Unable to display preview. Download preview PDF.