An examination and extension of Leslie's test of equal catchability.

To obtain valid estimates of population parameters from capture-recapture experiments the probabilities of capturing each living member of the population must be the same (though changes in sampling intensity may cause this probability to vary from one sample to another). This paper examines the power of Leslie's test of this assumption and shows how the main disadvantage of the test-that it uses only a fraction of the data from the experiment-may be removed.