A Bow-Net Trap for Ducks

Abstract

The nest trap described herein is a modification of a trap as old as the history of wildfowling. The principle is that of a net-covered hoop that pivots on an axle and falls or flips over the prey when activated by various release mechanisms. Earlier forms of traps using this principle are described by MacPherson (1897); the most similar one was the Nightingale trap. The Chinese trap was designed to capture birds for market and was activated by the bird with no consideration for its safety or welfare. One of the most recent uses of the principle was by Sowls (1949) in his nesting studies at the Delta Marsh in Manitoba. Sowls' trap employed a square bail with lead weights along the top; the weights increased the speed of fall and decreased the bounce of the bail. The trap was set by being propped open over the nest with a stick. It was released by jerking a string tied to the stick, allowing the bail to fall by gravity. This arrangement made it necessary for the hen to walk past the stick and under the net-covered bail to reach her nest. The spring-powered bow-net trap described here (Fig. 1A) cannot be accidentally sprung; therefore, it can be set and left until the operator is ready to trap the nesting hen. No obstruction appears above the nest to disturb the hen or influence her to desert. The trap operates efficiently in many types of cover, including buckbrush (Symphoricarpos occidentalis).