A Drop-Net Deer Trap

Abstract

A drop-net, 70 x 70 ft, made of No. 60 nylon with 3'/2-inch mesh, was developed to capture deer in areas of high deer density. An explosive trigger device was employed, fired by pushbutton or by radio control. In a 9-month period, about 340 animals were captured, mostly white-tailed deer (Odocoileus virginianus) and axis deer (Axis axis). The average catch was 10 and the maximum was 23. The drop-net trap is highly portable, can be erected quickly, and permits individual animals to be selected for capture. In trapping white-tailed deer and axis deer in central Texas in box traps, several problems were presented. Traps were bulky to move about and were readily sprung by other animals. Because of buck dominance at a bait station, a preponderance of bucks was often captured, resulting in the capture of too few does during the limited trapping period. The box traps were not big enough to accommodate axis deer which normally feed in a group. If several deer entered at one time the door would not close properly. Axis deer also were subject to excessive injury in a box trap. As a method to overcome some of these problems, the drop-net deer trap was developed as a means of mass capture in areas of high deer density.2 The drop-net is a modification of one developed by Glazener et al. (1964) for use on turkeys. Acknowledgment is due M. J. Anderegg for assistance in testing the net and developing deer-handling procedures. CONSTRUCTION OF THE TRAP Preliminary trials were made with a net of No. 60 spun polypropylene with 4-inch square mesh, but this net proved too light and was replaced with one made of No. 60 nylon, rated at 550 pounds breaking strength, with 3?-inch mesh. The net is 70 ft square The net was treated with Netset (Adams Net and Twine, East St. Louis, Illinois) to retard knot slippage and abrasion, and to give a dull finish. A 4-inch steel ring was tied at the center. Four lengths of pipe, 2 inches x 10 ft, were used as corner posts. All posts were equipped with a boat winch bolted in the center of the pipe and a 4-inch pulley bolted to the top as described by Glazener et al. (1964). A 12-ft length of 11/4-inch lightweight steel tubing supported the center of the net. Two %i6-inch chains, 16 ft long and fitted with hooks, were used at each corner as anchors. Stakes made from %4-inch reinforcing steel, 2? ft long, were driven to sufficient depth for deadmen. Corner triggers and center trigger, similar to the one described by Sugden (1956), are shown in Fig. 1. A 16-inch length of Y4-inch braided polyethylene (commonly used as tow rope for water skiing) was used as a trigger. With a special splicing fid, loops were spliced in each end of the trigger rope and a blasting cap inserted. The firing device contained a sensitive (Sigma 4 F; 10,000 ohms) relay to close the blasting-caps circuit. The wiring diagram is shown in Fig. 2. A simple push1 Contribution from the Pittman-Robertson Federal Aid in Wildlife Restoration Program, Project W-76-R, U. S. Bureau of Sport Fisheries and Wildlife and the Texas Parks and Wildlife Department cooperating. 2 Hawkins et al. (1968) have recently employed the cannon net for trapping deer, to avoid difficulties associated with box traps.