Table 3.

Sign of the determinant and trace of the Jacobian matrix at each equilibrium point in case (1).

Equilibrium point	Sign of determinant	Sign of trace	Stability
E(0, 0)	+	−	ESS
S(0, 1)	−	Uncertain	Saddle point
N(1, 0)	−	Uncertain	Saddle point
K(1, 1)	+	+	Unstable