Conjecture on cyclical fold bifurcations in a predator-prey model with group defence

Let the predator-prey model described in the paper be given, with its parameters and equilibria as defined there. Cyclical-fold conjecture. There exist parameter regimes under which a cyclical fold bifurcation is possible. The claim is presented as a further possible mechanism for the collision and annihilation of limit cycles, and no proof or resolution is supplied.