Table 1. Predictive variables used in modeling, acronyms, and data summaries. Sample point mean and range for each study area are shown as years combined. Abundance of insect orders is expressed as catch-per-unit-effort; all other variables show units in parentheses. No artificial mean is derived for ordinal and binary variables, shown as "na." Variables not measured in Iowa and Wisconsin study areas are denoted by --.

Nova Scotia Iowa Wisconsin
Acronym Variable description
Mean
Range
Mean
Range
Mean
Range
Invertebrate Abundance
ARA Aranea in pitfalls
10.5
0.6-38.1
--
--
--
--
CHI Chilopoda in pitfalls
0.1
0-0.9
--
--
--
--
COLS Coleoptera in sweeps
5.4
0-113.0
--
--
--
--
COLP Coleoptera in pitfalls
10.6
1.0-110.6
--
--
--
--
DIP Diptera in sweeps
7.1
0-39.6
--
--
--
--
DIPL Diplopoda in pitfalls
0.1
0-1.5
--
--
--
--
HEMI Hemiptera in sweeps
13.6
0-74.3
--
--
--
--
HYM adult Hymenoptera in sweeps
1.0
0-7.0
--
--
--
--
ISO Isopoda collected in pitfalls
3.4
0-189.7
--
--
--
--
LEP adult Lepidoptera in sweeps
1.2
0-8.3
--
--
--
--
LHL LEP and HYM larvae in sweeps
2.2
0-11.0
--
--
--
--
LUM Lumbricina in pitfalls
0.2
0-2.4
--
--
--
--
ODO Odonata in sweeps
0.5
0-4.4
--
--
--
--
OPIL Opiliones in pitfalls
0.2
0-1.1
--
--
--
--
ORTH Orthoptera in sweeps
0.5
0-6.5
--
--
--
--
STY Abundance of Stylommatophora in pitfalls
0.3
0-7.0
--
--
--
--
Vegetation
ALF Presence/absence of Alfalfa
na
na
--
--
--
--
COV Live vegetative cover in a frame (%)
69.7
24.5-100
84.0
55.1-99.5
69.8
28.8-100
FORB Forb cover in a frame (%)
23.4
0-96.3
26.3
0-8.5
29.5
0-81.3
GR Grass cover in a frame (%)
76.6
3.8-100
52.2
8.2-81.1
70.5
18.8-100
HD Height/density (dm) of May vegetation
3.0
1.0-7.5
4.7
1.2-12.2
0.9
0-3.1
SPT Presence/absence of Spartina spp. (cordgrass)
na
na
--
--
--
--
Other
DIT Length of ditch (m) in point-count plot
2.8
0-11.5
--
--
--
--
HARV Harvest date in the current year
6 Jul
6 Jun-15 Aug
--
--
--
--
HPY Harvest date in the preceding year
5 Jul
6 Jun-15 Aug
--
--
--
--
Pcbobo Conditional detection probability for Bobolink
0.44
0.42-0.45
--
--
--
--
Pcsavs Conditional detection probability for Savannah Sparrow
0.41
0.4-0.45
--
--
--
--
Pcnsts Conditional detection probability for Nelson’s Sparrow
0.40
0.35-0.42
--
--
--
--
YR 2002, 2003, or 2004
na
na
--
--
--
--

COLS and COLP represent prey abundance estimates from the same taxonomic order, but were considered as separate variables because they reliably sampled different families (Elateridae (click beetles) by sweeps, and Carabidae (ground beetles and tiger beetles) by pitfalls).