Table 3. Log likelihood (LL), number of parameters (K), AIC, ΔAIC, and Akaike weight (w) for the top three models of the initial and final analyses of American Coot (Fulica Americana) nest survival at Grays Lake, Idaho, 19972000. The initial candidate set of models included age (IAGE) and date (IDATE) and their quadratic functions; the final candidate set of models included age, date, water depth (WDEPTH), nest vegetation (NESTVEG), and year x treatment (YEAR × TRT) variables, including the quadratic terms for age, date, and water depth. Effective sample size was 11,081.

Models LL K AIC ΔAIC w
Initial candidate set of models
Global model: IAGE, IAGE², IDATE, IDATE² -609.2 5 1228.5 0 > 0.99
IAGE, IAGE², IDATE -618.2 4 1244.4 15.9 < 0.01
IAGE, IAGE² -632.0 3 1270.0 41.5 < 0.01
           
Final candidate set of models
IAGE, IAGE², IDATE, IDATE², YEAR × TRT, WDEPTH,
  WDEPTH²
-548.8 22 1141.6 0 0.58
IAGE, IAGE², IDATE, IDATE², YEAR × TRT, WDEPTH -550.8 21 1143.7 2.0 0.21
Global model: IAGE, IAGE², IDATE, IDATE²,
  YEAR × TRT, WDEPTH, WDEPTH², NESTVEG
-548.2 24 1144.5 2.9 0.14