A Model of the Effect of Environmental Variables on the Presence of Otters along the Coastline of the Isle of Skye

Table 4

Results of backward stepwise regression model.

Variable	B	SE	Wald	df	Sig	R	Exp(R)
Geology			38.51	6	0.00	0.18
Geology(1)	−1.09	0.31	12.04	1	0.00	−0.11	0.34
Geology(2)	0.98	0.33	8.64	1	0.00	0.09	2.67
Geology(3)	−0.20	0.52	0.15	1	0.69	0.00	0.82
Geology(4)	0.47	0.25	3.53	1	0.06	0.04	1.60
Geology(5)	−0.61	0.21	8.74	1	0.00	−0.89	0.54
Geology(6)	−0.41	0.25	2.59	1	0.11	−0.03	0.67
Height	−0.01	0.01	5.24	1	0.02	−0.06	0.98
Pools	2.90	0.33	76.11	1	0.00	0.29	18.24
Constant	−0.31	0.17	3.22	1	0.07

Geology(1): Lewisianl; Geology(2): Torridonian; GEOLOGY(3): Cambrian; Geology(4): Mesozoic; Geology(5): Tertiary Lava; Geology(6): Tertiary Intrusive.
Height: height 25 m from High Water Mark.
Pools: number of freshwater pools.
B: logistic regression coefficient.
SE: standard error of the logistic regression coefficient.
Sig: significance of Wald statistic. (The Wald statistic has a chi-square distribution. When a variable has a single degree of freedom, the Wald statistic is the square of the ratio of the coefficient to its standard error).
R: partial correlation coefficient of the individual variable.
Exp(R): factor by which the odds of finding otters change when the individual unit increases by one unit.