Traps and snares indiscriminately lure in wildlife and pets. Animal traps fall under two categories: restraining or killing. Restraining traps hold the animal until the trapper arrives to kill it. Kill traps are meant to result in immediate death and are used either on land or underwater. The terrestrial versions snap the neck or spine. Underwater traps render the animal unconscious until death. Traps do not discriminate between species and often non-target animals are caught. They can capture or kill threatened and endangered species, birds, domestic animals, and even humans.
a. Restraining Traps
Restraining traps come in five varieties: 1) stopped neck snares: wire loops which are arranged vertically with the intent of having the animal’s head enter the wire loop, which then tightens around the neck, but is stopped at a certain diameter. 2) Leg-hold snares: wire loops placed horizontally and designed to restrain an animal’s leg(s). 3) Leg-hold traps: either padded or unpadded and consisting of two jaws that open to 180 degrees and when triggered, fasten onto an animal’s leg or foot. 4) Box or cage traps: using an opening and bait to attract an animal, a box trap’s trigger causes the door to slam shut and capture the animal. 5) Pitfall traps: used to capture small terrestrial mammals into a smooth-sided container, which may contain bait.
Animals frequently sustain injuries from restraining traps such as physiological trauma, dehydration, exposure to weather, or predation by other animals or death because of restraining traps. Animals released from restraining traps may later die from injuries and/or reduced ability to hunt or forage for food.
Trapped animals respond in two ways from traps: psychological stress and or pain, and secondarily from exertion. The former can significantly alter hormones, enzymes, electrolytes and lead to long-term muscle damage.
In a review of 39 studies, Iossa et al. (2007) found that most leg-hold traps cause significant injuries. Even padded leg-hold traps caused minor and major injuries. Animals restrained in leg-hold traps suffer stress, and because of poor selectivity in captures, traps can reduce the survivability of released animals.
In a study by the USDA-National Wildlife Research Center, Shivik et al. (2000) found that traps that had the greatest success for capturing animals were the least selective, caught the most non-target species, and caused the most injuries. Non-target species may experience high amounts of mortality.
Leg-hold traps are considered inhumane by a number of countries and are banned in 80 countries, including the European Union. In the United States, traps are banned or limited in some states including in Arizona (1994 initiative), California (1998 initiative), and Colorado (1996 initiative).
b. Kill Traps
According to Iossa et al. (2007), five kinds of kill traps are utilized: 1) Deadfall traps which use gravity to kill an animal by crushing its skull, vertebrae, or vital organs. 2) Spring traps of two varieties—one has a bar that (usually) crushes the animal’s neck; and two, a trap that uses rotating jaws. 3) Killing snares of two kinds. The first, a self-locking snare that tightens as the animal pulls to escape, and the second, a power snare that uses springs to quickly tighten a noose. Both asphyxiate. 4) Drowning traps that hold the animal underwater until the animal dies from hypoxia, a shortage of oxygen in the blood. 5) Pitfall traps have water at the bottom. Rodents or small animals are induced to enter them and drown.
Some propose that if the purpose of capturing an animal is to kill it, then killing traps may be more suitable as the animal is not left in pain, shock, dehydrated, and at risk for predation (Harris et al. 2005). Kill traps are enormously faulty, however, and should not be used.
Of the 23 kill traps reviewed by Iossa et al. (2007), 18 failed to render the animals unconscious in the recommended time. Other welfare restrictions involve injured animals escaping and mis-strikes. The latter refers to metal clamping down on an unintended body part (Iossa et al. 2007). Iossa et al. (2007) found that mis-strikes occurred up to 10 percent of the time. In neck snares used on coyotes (Canis latrans), mis-strikes ranged from 8-14 percent, and the percentage of animals that remained alive in kill traps ranged from 17-86 percent. Furthermore, the authors found that coyotes escaped from kill traps from 3-13 percent of the time. These data show that kill traps are enormously inefficient at quickly killing as is intended. The AVMA echoes these sentiments. It said that kill traps are controversial because they can produce a prolonged and stressful death that is not within the AVMA’s criteria for euthanasia (2007).
Beavers (Castor canadensis) and river otters (Lontra canadensis), adapted to aquatic life, are adept are swimming and diving for long periods. Thus, death by hypoxia is slow even if the animal struggles; these animals often become distressed while attempting to escape from an underwater trap (Iossa et al. 2007).
Technologies such as water diversion devices behind beaver dams, which prevent flood events, make trapping beavers unnecessary (Muth et al. 2006).
If an animal gets trapped it may be injured, which raises welfare concerns, especially if it escapes (Iossa et al. 2007). Trappers have developed most traps, their primary concern is undamaged pelts, not quick and humane deaths (Iossa et al. 2007).
Not only does the public generally abhor trapping, so do most wildlife professionals (Muth et al. 2006). Kill traps may not actually be “quick” while killing, and they may cause suffering or injury to animals that is unacceptable under standards suggested by researchers cited here, the ISO, and the AVMA. Dozens of studies concerned with the effectiveness of traps, the welfare of animals, and the attitudes of people have come out in recent years. Therefore, we call upon Wildlife Services and states to ban traps and use more efficacious and less cruel, non-lethal means.