Stability and bifurcation in a delayed predator–prey system with Beddington–DeAngelis functional response

We consider a delayed predator–prey system with Beddington–DeAngelis functional response. The stability of the interior equilibrium will be studied by analyzing the associated characteristic transcendental equation. By choosing the delay τ as a bifurcation parameter, we show that Hopf bifurcation can occur as the delay τ crosses some critical values. The direction and stability of the Hopf bifurcation are investigated by following the procedure of deriving normal form given by Faria and Magalhães. An example is given and numerical simulations are performed to illustrate the obtained results.  2004 Elsevier Inc. All rights reserved.