FIG. A1. The frame of each enclosure was made from untreated pine lumber in the shape of a trapezoidal prism (length = 3.66 m, width = 1.22 m, height of end in pond = 1.22 m, and height of end on bank = 0.61 m).

Polyethylene netting (0.32 cm mesh, XV-1348, Industrial Netting, Minneapolis, MN, USA) was attached to the top and side faces using furring strips. The net opening was large enough to be permeable to small invertebrates, tadpoles and newt larvae, but not adult newts. The bottom of the enclosure was sealed with two layers of 6 ml black plastic sheeting with a layer of multi-purpose plastic netting included between them for stability.