Bats and Bridges- Table 1: Statistical Results

Table 1: Statistical Results

Paired Comparisons Multiple Regression Results

Bridge characteristics t-ratio p-value

crevice depth 6.19 0.000

crevice width 4.61 0.000

Closed crevice top 6.09 0.000

Substrate under bridge; bare 2.37 0.021

Roost substrate; metal -5.15 0.000

Statewide Evaluations t-test Results for Day Roost Characteristics

Micro-habitat characteristics Bridges Culverts

t-ratio p-value t-ratio p-value

Bridge type

prestressed concrete girder with diaphragms 2.04 0.0207 n/a n/a

Structure measurements:

height 22.4838 0.0000 23.4409 0.0000

width 38.0686 0.0000 109.438 0.0000

length 45.0299 0.0000 37.7501 0.0000

Crevice measurements

width 5.9091 0.0000 n/a n/a

depth 3.9174 0.0000 n/a n/a

height above substrate 32.8268 0.0000 n/a n/a

Roost characteristics

substrate metal -3.2517 0.0006 -0.5306 0.2978

substrate concrete 1.9484 0.0257 0.6887 0.2455

open above -3.8135 0.0001 n/a n/a

closed above 3.8186 0.0001 n/a n/a

roost texture 2.0115 0.0221 2.3705 0.0089

Macro-habitat characteristics

Regional

longitude 6.5435 0.0000 0.1162 0.4538

latitude -3.1603 0.0000 -4.6176 0.0000

ecoregion 2 -2.318 0.0102 -3.1706 0.0008

ecoregion 4 -4.0358 0.0000 -5.8771 0.0000

ecoregion 5 -0.8409 0.2002 -4.8726 0.0000

ecoregion 9 -1.5605 0.0593 -2.2484 0.0123

ecoregion 10 1.9534 0.0254 -5.3086 0.0000

Local landuse (within 1 mile (1.6 kilometers))

mixed woodland/grassland 2.3523 0.0093 -0.0012 0.4973

n/a = not applicable

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Paired Comparisons Multiple Regression Results

Bridge characteristics	t-ratio	p-value
crevice depth	6.19	0.000
crevice width	4.61	0.000
Closed crevice top	6.09	0.000
Substrate under bridge; bare	2.37	0.021
Roost substrate; metal	-5.15	0.000

Statewide Evaluations t-test Results for Day Roost Characteristics


Micro-habitat characteristics	Bridges		Culverts

	t-ratio	p-value	t-ratio	p-value
Bridge type
prestressed concrete girder with diaphragms	2.04	0.0207	n/a	n/a

Structure measurements:
height	22.4838	0.0000	23.4409	0.0000
width	38.0686	0.0000	109.438	0.0000
length	45.0299	0.0000	37.7501	0.0000

Crevice measurements
width	5.9091	0.0000	n/a	n/a
depth	3.9174	0.0000	n/a	n/a
height above substrate	32.8268	0.0000	n/a	n/a

Roost characteristics
substrate metal	-3.2517	0.0006	-0.5306	0.2978
substrate concrete	1.9484	0.0257	0.6887	0.2455
open above	-3.8135	0.0001	n/a	n/a
closed above	3.8186	0.0001	n/a	n/a
roost texture	2.0115	0.0221	2.3705	0.0089

Macro-habitat characteristics

Regional
longitude	6.5435	0.0000	0.1162	0.4538
latitude	-3.1603	0.0000	-4.6176	0.0000
ecoregion 2	-2.318	0.0102	-3.1706	0.0008
ecoregion 4	-4.0358	0.0000	-5.8771	0.0000
ecoregion 5	-0.8409	0.2002	-4.8726	0.0000
ecoregion 9	-1.5605	0.0593	-2.2484	0.0123
ecoregion 10	1.9534	0.0254	-5.3086	0.0000

Local landuse (within 1 mile (1.6 kilometers))
mixed woodland/grassland	2.3523	0.0093	-0.0012	0.4973

n/a = not applicable