Figure 12
From: Bogdanov–Takens bifurcation of a Holling IV prey–predator model with constant-effort harvesting
(a) The point BT is corresponding to the origin of Fig. 4. When \((\mu _{1},\mu _{2})\) varies along curves \(SN^{+}\), H and \(H_{1}\), respectively, the points CP, \(GH^{+}\) and \(GH^{-}\) can be encountered. (b) The bifurcation portrait for \(h_{1}=0.1\) and \(h_{2}=0.3\), \(SN_{c}\) indicates the saddle-node bifurcation curve originating from the point CP. \(H^{+}\)(\(H^{-}\)) and \(T^{+}\)(\(T^{-}\)) express the Hopf bifurcation curve and the fold bifurcation curve of the cycles originating from \(GH^{+}\)(\(GH^{-}\)), respectively