Harvesting birds with traps has been practiced since well before recorded history. There are multiple reasons why birds have been targeted.
- They are easy to kill, relatively speaking. Simply because birds must be light enough to fly, their bone structure tends to be delicate. Consequently it doesn’t require great force to kill or cripple a bird.
- Many birds are migratory, and/or flock together for much of the year. There are opportunities to grab multiple individuals in one location.
- Bird feeding locations tend to be easily visible and you can count on birds returning there to feed repeatedly so trap locations can be scouted out.
- Birds don’t tend to be the sharpest tools in the shed. It can be far more difficult to trap mammals than birds. “Bird Brain” is not a compliment.
The trap I am going to write about in this post is the Clap Trap. It is quite simple to construct and is suitable for use on larger birds as long as you use stronger material. It lies flat on the ground and requires little metal or wood so it is not conspicuous. It can be operated by one person, but probably will be most successfully used with two people. If there is only one person available, you will have to make a slight accommodation for that.
First up let me give a tip of the hat to the University of Nebraska – Lincoln. They produced a report called “Techniques Employed to Capture Whooping Cranes in Central Florida” for presentation at the 2008 North American Crane Workshop Proceedings.
Whooping Cranes were being reintroduced to Central Florida. This necessitated periodic trapping to band, attach transmitters, check the health of and more or less monitor the birds. The report mentions that they used six different methods of crane capture. The clap trap was responsible for 42% of their captures.
This six page document, with complete instructions on building and use is available here.
Below is an example of how the trap looks after operation and also some lower resolution images of the trap construction.
As you can see the materials used for construction are quite simple. The netting they used in their efforts was multifilament nylon gill netting with a string diameter of 0.55 mm. They also used two 15 metre long braided nylon ropes, threaded through the top and bottom of the net sections. In addition, to form the trap they used four 1.2 m long, 1.3 cm diameter ( 1/2″) dowels. In the illustration above the dowels are in pairs, standing vertically. The white pieces of rope stand out from the gill net by virtue of their greater diameter. The two diagrams below show the arrangement of the pieces.
The component parts of the Clap Trap bird trap.
As you can see in the photograph, and as indicated in the drawing, the trap must be operated by an observer, who must maintain tension on the trigger wires to keep the top edges of the trap closed. If the trigger person was near a solid object ( a sapling, sturdy stake in the ground etc.) then a couple of quick turns could secure the trigger wires and the observer could leave cover to collect the bird. Otherwise, a second person is necessary.
The trap works on tension and geometry and is simple to replicate in different sizes. Several stakes are required to be driven into the ground to hold the bottom ropes and dowels in place, but everything is explained in the report. I encourage you to download it.
The authors report, when speaking of the clap trap design “One of its most appealing features was its ability to safely catch multiple cranes at once. The traps were fairly easy to build and inexpensive (each under $40)…”
They further note, “Though productive, the clap trap was not perfect. Traps
were time consuming to set up, and if we did not take great care to set them up properly, the traps would not trigger correctly.”
The traps proved to be their most successful method of capturing birds. “We triggered the clap trap a total of 17 times. Six of those 17 times we caught 1 bird, 5 we caught 2 birds, and 4 we caught 3 birds. On 2 attempts we caught nothing. Of the 17 attempts made, we caught birds on 15, resulting in an
88% capture probability. ”
I have several thoughts on this trap. First, it seems as if it could be made with expedient materials. If you had a volleyball net or a tennis net or protective netting for a fruit tree or possibly even lightweight wire mesh, I think you could construct one of these. The authors note that they did colour the net and rope to camouflage it. I expect that leaf litter or other vegetative material could be used.
I also wonder about the ability to put two of these traps in a line, both connected to the same trigger wire. The opportunity to capture multiple birds is one of the very attractive features of this arrangement. The speed with which the trigger wires are pulled must be fast enough to trap the birds. Perhaps a spring mechanism and release would improve over a simple tug from a trigger person.
I hope you have found this post on the Clap Trap informative. Keep your eye out for more in the near future.