RESEARCH

SHORT-EARED OWL

REFERENCE MATERIAL

Verbail trap

The Verbail trap is a pole-mounted apparatus that has been quite successful for some in catching Short-eared Owls.  The basic principle of it is that the trap is attached to a fence post or other pole in an open area, preferably away from any other perches of similar or greater height, so that the owl will be attracted to land on it.  The trap can also be made more attractive by placing a small rodent in a protected cage at the base of the pole upon which the trap is set.  There is a small platform trigger upon which the bird lands, activating a spring release that causes a rope noose to be released and close around the bird's feet.  This is tied to a separate line that allows the bird to flutter to the ground safely, so that it is never at risk of hanging by its feet.  It is important to note that such traps may be operated only by those who have the appropriate federal permits, and that they should be watched at all times so that birds caught can be removed as soon as possible.

Below, a few photos illustrating the setup of a Verbail trap, and a brief video showing how it is triggered.  Thanks to Jim Duncan of Manitoba Conservation for providing the trap and demonstrating its operation.  All photos/videos by Marcel Gahbauer.


The first step in setting the trap is putting the spring on the post.  There are two nails on the rear of the post upon which the two ends of the spring are placed.  The rope that constitutes the noose is at this point hanging (permanently attached) to the two ends of the spring.


The next step is to raise the holding pin to lock the two ends of the spring in place until release.  Note that the top of the holding pin extends just slightly through a metal tab connected to the trigger platform, so that when the trigger is depressed, the tab rises, and the holding pin falls free, in turn releasing the spring.


The noose has now been set in place.  The metal ring surrounding the trigger platform is there simply to provide support for the noose, and as such, it has three small prongs around its circumference to support the rope (only the one on the right is visible).  Also note that the "S-ring" that was previously hanging loose at the bottom of the loop in the first photo has now been positioned behind the pole, and behind the holding pin.  Thus, when the trigger is depressed and the holding pin falls, it takes the S-ring with it, resulting in the tightening of the rope noose around the legs.


The full set up of the Verbail trap, this arrangement including an attached wire cage base within which a small mouse could be placed to attract the owls to the trap.  Note the second rope attached to the spring, which will ensure that the owl can flutter to the ground safely, but at the same time will remain confined to a short distance from the pole.


Click here for a short video illustrating the operation of the Verbail trap.
(Warning, you may want to turn down your volume, as it is loud, and not relevant to the video in any case)

 

2002- The Migration Research Foundation Inc.