Rothery P., Newton I., Wesołowski T. 1997. Testing for density dependence allowing for weather effects. Oecologia 112: 518-523.

A test for density dependence in time-series data allowing for weather effects is presented. The test is based on a discrete time autoregressive model for changes in population density with a covariate for the effects of weather. The distribution of the test statistic on the null hypothesis of density independence is obtained by parametric bootstrapping. A computer simulation exercise is used to demonstrate the gain in statistical power by allowing for weather effects. Application of the method to time-series data on three species of butterflies and two species of songbirds showed stronger evidence of density dependence than two standard tests.

Key words: density dependence, weather effects, autoregressive model, statistical power, butterfly and songbird populations