Table 2. Top models from the Nova Scotia study area for abundance, occupancy, and reproductive activity of Bobolink, Savannah Sparrow, and Nelson’s Sharp-tailed Sparrow. Model notation follows Table 1. For comparison, the value of Akaike’s Information Criterion (AIC) is provided for the global and final models. The variance associated with the random effects of site and point-count station is provided for models with mixed effects. Parameter estimates and standard errors are presented in Table 3. Footnotes indicate the retained variables used in model building for each model set. For occupancy and reproductive activity models, variables were retained if they had a Mallow’s Cp score (Mallow 1973) above that of a null model. Variables were retained for abundance models if they were within the upper 50% of highest individual F-statistics and had at least 0.10 pr (|t|).

Model for Top Model Global AIC Best AIC ơ2 Site ơ2 Point
Bobolink
abundance (♂ + ♀) HD + HEMI + ORTH 386.4 364.4 0.337 0.324
abundance (♂) COV - ALF 272.2 234.2 0.149 0.131
abundance (♀)§ HD + HEMI 151.7 123.5 0.043 0.036
occupancy | HD - FORB 149.3 142.8 0.123 0.114
reproductive activity HD + ARA + DIP + ODO 152.2 149.8 -- --
Savannah Sparrow
abundance # DIP - CHI - HD 329.6 295.1 0.005 0
occupancy †† COLP - FORB - HD 49.3 42.2 0.007 0
reproductive activity ‡‡ OPIL - FORB 107.6 101.8 -- --
Nelson’s Sparrow
abundance §§ DIT + ORTH - ALF 8.4 -40.0 0.018 0
occupancy || DIT + ARA + LHL 235.1 228.8 0.001 0
reproductive activity ¶¶ HD + ARA - ALF -39.2 -44.1 -- --


ALF, COV, FORB, HD, HEMI, LIT, ORTH, SPT
ALF, COV, DIP, DIPL, FORB, HD, HEMI, LIT, ODO, SPT
§ ALF, DIP, HARV, HD, HEMI, HYM, LHL, LIT, ODO, ORTH
| COV, DIP, FORB, HARV, HD, LIT
ALF, ARA, COV, DIP, DIPL, GR, HD, HEMI, LIT, LUM, ODO, ORTH
# ALF, CHI, COLS, DIP, HARV, HD, ORTH, STY, YR
†† COLP, COLS, DIP, FORB, HD, LIT
‡‡ ALF, ARA, CHI, COLS, FORB, HPY, LUM, OPIL, ORTH, STY, YR
§§ ALF, ARA, DIT, HARV, HEMI, LIT, ODO, ORTH, SPT, STY
|| ALF, ARA, DIT, LHL, LIT, HARV, SPT
¶¶ ALF, ARA, HD, LIT, LUM, YR