On a log-linear approach to detecting ecological interactions in monitored populations
Article first published online: 2 NOV 2007
© 2007 The Authors
Volume 150, Issue 2, pages 250–258, April 2008
How to Cite
FREEMAN, S. N. and NEWSON, S. E. (2008), On a log-linear approach to detecting ecological interactions in monitored populations. Ibis, 150: 250–258. doi: 10.1111/j.1474-919X.2007.00770.x
- Issue published online: 2 NOV 2007
- Article first published online: 2 NOV 2007
- Received 17 January 2007; revision accepted 7 September 2007.
- generalized linear models;
- population growth;
We discuss a log-linear model for series of regular bird counts taken at a number of survey sites. The model is parameterized in terms of annual growth rates rather than actual indices of abundance, as is more frequently done. This not only permits easy estimation of and inference about these rates, but also allows us to model the effects upon population growth of covariates, such as the local presence of a competitor or predator, which may themselves vary in space and over time. A recursive relationship permits the expected count at a site to be functionally dependent upon the expected count at the previous visit. We discuss the advantages of using this relationship, rather than replacing the latter with their observed counterparts, as has been used previously.