A closure test for time-specific capture-recapture data

The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, litt le progress has been made in the development of omnibus tests of the closur e assumption. We present a closure test for time-specific data that, in pri nciple, tests the null hypothesis of closed-population model M-t against th e open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigrat ion, and is of intermediate sensitivity to permanent or temporary immigrati on. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.