Wild Animal Control
Human-wildlife conflict occurs in situations where humans and wild animals compete for resources and as the human population grows conflict is likely to increase (a topic discussed at the 2015 UFAW International Symposium: Animal populations – World resources and animal welfare).
When conflict does occur, it may be deemed necessary to control wild animal populations to: prevent damage to property (e.g. buildings, fences or ground); prevent loss and contamination of growing crops or stored foodstuffs; stop spread of disease to humans and other animals; reduce risk of injury to humans and other animals; and to protect indigenous species.
Common wild animals that are controlled by humans include: mice, rats, moles, rabbits, grey squirrels, opossums, and raccoons. However, any wild animal may be considered a nuisance, or ‘pest’ and this list is by no means exhaustive. When wild animal control is considered necessary, it is usually achieved through a combination of one or more of the following methods: exclusion, trapping and killing or release.
Which method is selected will depend on a number of factors, including: perceived humaneness (i.e. involves the minimum of pain, suffering or fear), efficacy, cost-effectiveness, target specificity, practicality, ease of application, speed of effect, durability, legality (the control of some animals, such as bats, badgers and deer is regulated or requires a licence), safety for operators and other people, environmental impact, and acceptability to the public (1).
UFAW has long been an advocate of the humane control of wild animals and in 1932 the University of London Animal Welfare Society (ULAWS, later to become UFAW) held a meeting on humane methods of trapping rabbits, which in turn led to the publication of the book ‘Man versus Rabbit’ by Dr AHB Kirkman. Dr Kirkman had carried out pioneering studies into more humane methods of controlling rabbit populations on behalf of ULAWS. The meeting, and the book, with its scientific approach, raised public awareness and helped to establish a climate for debate on the use of the leg-hold trap (a widely used trap which often led to a great deal of suffering, both in target and non-target animals). UFAW supported further research into the wild rabbit in 1938 and in 1946 UFAW initiated a research studentship to survey the mammalian fauna of Skomer Island, West Wales, to research the control of rabbits and to develop a humane poison for rats. UFAW continued to campaign against leg traps, in particular the gin trap (a mechanical leg trap) and in 1954 the Pests Act was passed which led to the phasing out and abolition of the gin trap in England, Scotland and Wales.
Since this time UFAW has funded further research into the humane control of various wild animal species and has also been involved in working groups on snaring and shooting to ensure that animal welfare is duly considered when producing best practice guidelines. In England snares continue to be employed as a means of controlling wild animals (predominantly foxes and rabbits) with the aim being to catch and restrain the target animal in the snare until it can be killed humanely. There are various guidelines for how best to use snares, such as they must be free-running (ie they loosen if the animal stops pulling, as opposed to self-locking which tighten by ratchet action); they must only be set in an area unlikely to catch non-target animals; and they should be checked once a day. Once an animal has been snared, then shooting (either using a rifle or shotgun) is the most commonly used method of dispatch eg when killing a snared fox, and is considered humane when carried out correctly.
Factors to be taken into account when aiming to achieve a humane kill with a firearm (eg when shooting a wild animal caught in a snare, or other trap, or free-running) include the following: weapon type, correct ammunition, skill of marksman, location, and potential for shot but lost rate (the likelihood of an animal being injured but not killed and therefore able to run away, which can lead to a high level of prolonged suffering).
Other animals affected by ‘pest’ control include mice and rats. Vast numbers of these animals are killed every year and the control methods currently available for these species are frequently inhumane. One of the most commonly used methods involves anticoagulant poisoning. Anticoagulant agents cause bleeding to occur into the gut, tissues, body cavities joints ad inside the skull - this is known to be very painful in humans, and is likely to be similarly painful in animals. Rats that have eaten anticoagulant poison show signs of weakness, lameness and breathing difficulties for up to 48 hours prior to death. This duration and level of suffering would not be legal in a laboratory setting, indeed the welfare of laboratory rats is tightly regulated, but the welfare of wild rats is not likewise protected. To help tackle this important issue, in 2006 UFAW held a Workshop on Rodent Control Methods and set up a Humane Rodent Control Working Group. The Working Group comprised scientists, veterinarians, and representatives from the pest control industry and the aim of the Group was to promote welfare improvements in the control of rodents. As a result of the Groups’ work, UFAW published guidance notes on humane rodent control. The guidance discusses measures that can be taken to avoid the need for control as well as the pros and cons, and legal implications where applicable, of different control options, including: preventing access; rodenticides (anticoagulants, alphachloralose, cellulose pellets); trapping (live-capture traps, spring-powered killing traps, glue boards, stretched rubber ring strangulation traps, gas traps, electrocution devices); repellents, and other methods. It is hoped that these guidance notes will result in less suffering, and ultimately improved welfare, by enabling people to either avoid control or to practice more humane methods of rat and mice control.
The scale of ‘pest’ control is huge with many millions of wild animals affected every year - the potential for suffering is therefore very great indeed. It is consequently vitally important that further research is carried out into the best ways to manage wild animal populations to ensure that where human-wildlife conflict does occur then control methods are carried out in the most humane manner possible.
References
- Baker SE, Sharp TE, Macdonald DW. Assessing Animal Welfare Impacts in the Management of European Rabbits (Oryctolagus cuniculus), European Moles (Talpa europaea) and Carrion Crows (Corvus corone). PLoS ONE. 11(1): e0146298. DOI: 10.1371/journal.pone.0146298.
Selected papers on wild animal control published in the UFAW Journal, Animal Welfare:
Hampton JO, Forsyth DM, Mackenzie DI. & Stuart IG. 2015. A simple quantitative method for assessing animal welfare outcomes in terrestrial wildlife shooting: The European rabbit as a case study. Animal Welfare. 24: 307-317. DOI: https://doi.org/10.7120/09627286.24.3.307. UFAW
Baker SE, Shaw RF, Atkinson RPD, West P, Macdonald DW. 2015. Potential welfare impacts of kill-trapping European moles (Talpa europaea) using scissor traps and Duffus traps: a post mortem examination study. Animal Welfare. 24(1): 1-14. DOI: https://doi.org/10.7120/09627286.24.1.001. UFAW
Baker SE and Macdonald DW. 2012. Letter: Not so humane mole tube traps. Animal Welfare. 21(4): 613-615.
Fraser D and MacRae AM. 2011. Four types of activities that affect animals: implications for animal welfare science and animal ethics philosophy. Animal Welfare. 20(4): 581-590. UFAW
Matthews F. 2010. Wild animal conservation and welfare in agricultural systems. Animal Welfare. 19(2): 159-170. UFAW.
Littin KE. 2010. Animal welfare and pest control: meeting both conservation and animal welfare goals. Animal Welfare. 19(2): 171-176. UFAW
Ioss G, Soulsbury CD, Harris S. 2007. Mammal trapping: a review of animal welfare standards of killing and restraining traps. Animal Welfare. 16(3): 335-352. UFAW.
Fox NC, Blay N, Greenwood AG, Wise D, Potapoy E. 2005. Wounding rates in shooting foxes (Vulpes vulpes). Animal Welfare. 14(2): 93-102. UFAW.
Mellor DJ, Littin KE. 2004. Using science to support ethical decisions promoting humane livestock slaughter and vertebrate pest control. Animal Welfare. 13(Suppl 1): 127-132. UFAW.
Reynolds JC. 2004. Trade-offs between welfare, conservation, utility and economics in wildlife management — a review of conflicts, compromises and regulation. Animal Welfare. 13(Suppl 1): 133-138. UFAW.
Mason G and Littin KE. 2003. The humaneness of rodent pest control. Animal Welfare. 12(1): 1-37. UFAW.
Other UFAW publications:
Animal populations – World resources and animal welfare. Abstract booklet of the UFAW International Animal Welfare Science Symposium, held in July 2015, Zagreb, Croatia. Available online at: https://www.ufaw.org.uk/downloads/ufaw-symposium-2015---animal-populations-programme-booklet.pdf.
Guiding principles in the humane control or rats and mice. 2008. Guidance notes produced by the UFAW Humane Rodent Control Working Group and available online at: https://www.ufaw.org.uk/rodent-welfare/rodent-welfare.
The Exploitation of Mammal Populations. Taylor VJ and Dunstone N (Eds). 1996. A selection of peer-reviewed papers from a conference jointly organised by UFAW and the Mammal Society. Published by Chapman & Hall. ISBN 0 412 64420 7.
Welfare guidelines for the re-introduction of captive bred mammals to the wild. International Academy of Animal Welfare Sciences. 1992. Published by the Universities Federation for Animal Welfare (UFAW). ISBN 0 900767 80 4.
Man versus rabbit. Kirkman AHB. 2nd Edition. 1934. ULAWS Monographs, No 4b. Published by the University of London Animal Welfare Society (ULAWS). London
