By Pierre Canac-Marquis | Trap Research, Testing and Development Program, Fur Institute of Canada
The selectivity of traps and trapping methods is a very important issue in current fur-bearing animal trapping practice. The accidental capture of non-targeted species in traps set for commercial trapping and even for damage or population control has become the war horse of groups opposed to trapping, raising concerns among general public.
The growth in populations of deer and birds of prey, the urban sprawl, and therefore the presence of companion animals outside cities, are important and new realities that must be taken into account when setting traps.
Several methods and trap components are now available that make it possible to avoid such “accidents” or unintentional captures of non-targeted species. By “non-targeted species”, we mean those that are not wild furbearing animals in the targeted group.
A “target group” refers to species difficult to distinguish by their behaviour and common habitat and which risk being captured in a trap set up to catch another species. For example: otter and beaver, mink and muskrat, fox and coyote.
The non-targeted species thus consist primarily of domestic animals, livestock, deer and birds.
One of the main characteristics of modern trapping systems is their selectivity. In Canada, this issue can primarily be covered by adequately training trappers and by regulations. This is because selectivity is most of the time more closely linked to the trapping method than to the devices chosen by trappers.
The following factors influence the degree of selectivity of the various systems and methods of capture and provide guidance for achieving this very important objective:
A) Setting site:
- Devices set underwater target semiaquatic species, excluding terrestrial species;
- Traps located in certain very specific habitats limit the number of species that may be captured (e.g. boreal forest, marshes);
- Devices set in trees or high up eliminate species that cannot climb;
- Traps set in dens/huts target specifically the species that live there;
- Devices set on trails specific to one species limit the number of species that could be captured;
- The dispersion and distance of snares in relation to the attractants used (bait, lures) may make it possible to avoid the accidental capture of dogs and birds of prey;
- The positioning of killing traps (height from the ground) determines which species may potentially access the trap.
B) Trap types:
- Killing traps that are effective for several species frighten away others (e.g. Conibear type traps vs canids);
- Live capture cages allow for some species to be caught, while others systematically avoid entering them;
- Small traps avoid/prevent the capture of large animals and vice versa;
- The presence of a release system on a snare allows an unintentionally captured deer (snared by a leg) to free itself.
C) Position of the trigger mechanism:
- The configuration of the trigger in killing type traps determines which species may pass through them without triggering the trap, or without becoming caught if the trap is triggered.
D) Tension of the trigger:
- The specific tightness of the trigger’s tension adjustment screw, which is a part of certain traps, limits the capture of lighter species (pan trigger);
- An object (moss, stick) under the trap’s pan limits the capture of lighter species;
- Certain trap adjustments increase the pressure of the springs on the trap and increase the pressure required to trigger the trap (e.g. selec ting the dog notch on a Conibear type traps).
E) Types of lures and bait:
- Certain lures and bait may be specific to certain species;
- The distance between the lure/bait and the trap’s pan may be specifically adapted to the species to be captured;
- The fact that the bait is hidden or not.
F) Trap handling:
- Human odour may chase away some species/wary individuals;
- Camouflaged traps (hidden or not).
G) Time of year or cyclical abundance:
- Depending on the trapping period/time/season, we are likely to catch individuals of certain species, sex and age groups;
- Local presence and abundance of non-targeted species (abundance cycle).
H) Visual obstacles (Camouflage):
- Fencing or barriers and other obstructions may be used to limit access to certain species (avoiding entry into the trap).
Several selective trapping methods and devices are shown in different trapper’s education programs. Some are available in the content of the “Best Trapping Practices”, which is available at the following internet address: fur.ca/downloads/ms_4528.pdf
Selective trapping is an essential aspect and must be taken into consideration at all times when traps are being set to avoid accidental captures of non-targeted species. It is the responsibility and the duty of every individual to use adequate and selective trapping methods and traps so that such “accidents” do not occur.
This is even more important when cats and dogs are involved since they are as precious to some people as their children. Any unfortunate incident tarnishes the reputation of all trappers including you. Any incident is one too many!
All trap users must be vigilant for the good of everyone!