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Table 6 Ordinal linear model of shorebird richness

From: Temporal and spatial variation in bird and human use of beaches in southern California

Independent variable

Effect

df

Chi-Square

 P

Slope

−0.09

1

2.50

0.1138

Month

 

11

77.34

<.0001

Year

 

3

1.50

0.6831

Sqrt(% algal wrack)

0.08

1

1.15

0.2831

Sqrt(Distance to estuary)

0.00

1

1.39

0.2376

Sqrt(Human activity)

−0.14

1

12.01

0.0005

Tide

−0.08

1

0.58

0.4474

Month*Tide

 

11

13.41

0.2676

Tide*Slope

−0.04

1

1.49

0.2227

# observers

 

1

0.91

0.3404

G

 

1

1.87

0.1712

W

 

1

1.31

0.2525

F

 

1

2.25

0.1337

K

 

1

0.99

0.3196

T

 

1

0.97

0.3245

N

 

1

0.18

0.6689

C

 

1

0.12

0.7275

B

 

1

1.12

0.2904

  1. R-square = 0.11, ChiSquare = 198.1 DF = 40, P <.0001. Estuary refers to the inverse of the shortest distance from the transect to an estuary. Letter codes refer to observers. Effect sign is negative to that given in statistical output to indicate the effect of the independent variable on the dependent variable as in a General Linear Model.