Investigators have an obligation to identify and assess the consequences of their research activities on wild animals, populations and the environment. Whenever possible, action should be taken to avoid, alleviate or minimize any adverse effects. Research activities should include the collection of adequate samples to ensure valid research results, yet be balanced to minimize adverse effects. Investigators should always weigh potential gain in knowledge against the negative consequences of disturbance. Although short-term detrimental effects may result from research activities, research can ultimately yield long-term positive effects for the affected population.
Observer-related disturbance can be characterized in at least two ways. First, disturbances may create biases that affect both the gathering and analysis of data, if the actual process of measurement acts to alter the parameter being measured. Second, research activities might effect the status and well-being of the study subjects themselves. Both effects vary along a continuum from those that are overtly obvious to those that are subtle and difficult to detect.
Although they are usually less severe, many of the effects of field investigations are similar in nature to those that result from non-scientific human activities such as tourism and other general recreational pursuits.
The following provides general guidelines for minimizing the impact of research activities in the field:
Investigators must also take into consideration the response research animals may have to the sounds, the behaviours and the simple presence of humans. In addition, species that are not under study may be disturbed.
Whether one is collecting study animals for eventual release or for museum preparations, the same humane considerations should apply. These animals should not be exposed to excessive or inappropriate handling, conspecific aggression, predation, temperature extremes, or undue suffering.
Each investigator should observe and pass on to students and co-workers a strict ethic of habitat conservation. Because many essential details of life history may remain unknown until a study is well along, collecting should always be conducted so as to leave the population and habitat as undisturbed as possible.
The permanent removal of large numbers of animals from any wildlife population should be avoided, unless justified for very specific scientific reasons. Similarly, the collection of large numbers of females from any population for destructive sampling should be avoided. Systematists should investigate extant collections for suitable specimens before conducting any field work. If the purpose of an experiment is to alter behaviour, reproductive potential or survivability, the interference should be no more than is determined necessary by the investigator to accurately test the hypotheses under question.
Investigators must obtain and comply with all permits required for the capture, handling and collection of those mammals which are of the correct species and in the appropriate jurisdiction. In addition, they must be familiar with the current list of threatened and endangered species and must comply with all rules and regulations pertaining to these and all other categories of mammals.
Investigators should be familiar with traps and trapping techniques and should choose a trap type that is best suited to the species and type of study. Capture techniques should prevent or minimize injury or damage to the animal. Care should be exercised to avoid accidental capture of non-target species. Special consideration should be given to the setting of capture devices in areas that are frequented by pets and children. Trapping and handling equipment should be routinely inspected and maintained in good working order. At the end of each collecting period traps should be properly closed or removed.
Wild animals are sensitive to heat, cold, thirst, energy deprivation and stress, and investigators must make every effort to avoid trap deaths from such factors as temperature extremes, stress, shock, and capture myopathy. Animals should not be left in traps longer than is absolutely necessary, although this will vary with the species, weather, objectives of the study, and trap type. Traps should be shaded or positioned to avoid full exposure to the sun and, where possible, trapping or netting should be avoided in windy, cold and rainy weather. Captured animals can injure themselves trying to escape, even from metal walk-in traps. These injuries reduce the specimen's scientific value and cause needless suffering. Under extenuating circumstances there may be a need to position traps a long distance from the researcher. In these instances the traps should only be set when weather stresses can be minimized and they should be checked as frequently as possible.
Dependent Young: The trapping of wild animals with dependent young should, as a general principle, be avoided. When this is unavoidable, it must be accompanied by a program to either remove or kill the dependents if the parent cannot return. Every effort should be made, in advance of trapping, to locate lairs and nesting areas to minimize the inadvertent capture of these animals.
Bat Trapping: The capture of bats poses special problems which do not apply to most other mammalian species. Mist netting, in which the animals become entangled in a very fine net, is the most commonly used technique. Because the captured bats will struggle and increase their chances of serious entanglement or injury, these nets should be monitored continuously. In addition, they should be set away from large concentrations of bats, so that an unmanageable number of animals is not captured at a single time. Harp traps are preferable whenever a large number of bats is likely to be caught at a roost or cave entrance because they help to avoid the trauma that is often associated with the use of mist nets. These traps have two parallel frames supporting a series of vertical monofilament lines. For some unknown reason the bat becomes trapped between the vertical lines and is subsequently funneled into a holding bag.
Any form of trapping around maternity colonies should be avoided. In addition, researchers should avoid excessive or repeated disturbances of roost sites.
In some instances, wildlife research may necessitate the judicious collection of whole animal or tissue specimens in the field. This may be done to provide information on species identification, genetics, population structure and dynamics, comparative anatomy and physiology, evolutionary relationships, behaviour, parasites and diseases, economic factors, geographic and microhabitat distributions, and ecology in natural or disturbed habitats. The knowledge that results from these studies may be applicable to other biological sciences and may help to facilitate decisions involving management policies for all species, whether endangered or economically important, for the conservation of habitats, ecosystem analysis, pest and disease control, retrospective studies, predator control and domestication of species.
Many specimens removed from the field are used collaboratively and deposited in the collections of natural history museums or biological data banks for future studies. Museum collections are curated repositories for whole specimens and their parts, whereas biological banks are collections of histologically or cryobionically preserved organs, tissues (including live cultures), cells (including sperm and ova) or embryos. Both kinds of repositories allow qualified researchers access to study collections. It is strongly recommended that, when appropriate, voucher specimens and biological samples be retained at the conclusion of field investigations, so that they will be available for use by future investigators. Communication with researchers in other jurisdictions is recommended in order to maximize the use of and information gathered from biological samples.
Humane methods of kill trapping and shooting are techniques that kill the animal instantaneously while avoiding damage to the body parts that are required for the investigation.
Shooting may be the most effective and humane method to collect larger mammal species, but it is rarely justified or required. Researchers planning to use firearms must be experienced in their proper and safe use and must comply with laws and regulations governing their use. The firearm and ammunition load should be appropriate for the species to be collected. Every effort should be made to avoid wounding animals, not only to minimize suffering, but also to maximize the probability of retrieving rather than losing the specimen. In the event of accidental wounding, the animal must be tracked and recovered. In most cases, shooting is reserved for the collection or euthanasia of terminally ill or severely injured animals.
For smaller animals, the use of kill-traps for collecting scientific specimens must be carefully and appropriately justified. If they are to be used, they should be checked at least once daily and positioned so they avoid or minimize the inadvertent capture of non-target species. For example, snap traps, which are usually set for nocturnal animals, should be sprung early in the day in order to avoid the accidental capture of any diurnal species. Methods commonly used for kill-trapping include snap traps (e.g. Victor trap), Museum Specials (snap trap, modified to reduce skull damage), Macabee traps for pocket gophers, Harpoon traps for moles and Conibear traps for medium sized mammals. Considerable review of trap design and installation techniques is advised prior to the start of a study.
The use of steel jawed traps as kill-traps is not considered to be appropriate because these devices hold the animal rather than killing it immediately. If such traps must be used, they must be checked very frequently in order to minimize the animal's suffering. With this live trapping method, it is the investigator's responsibility to safeguard the trapped animal against the effects of heat, cold, thirst, energy deprivation and stress, and ensure appropriate methods are available to treat injuries, restrain, and release animals.
See 2.10.2 Euthanasia of Study Animals
The nature of restraint will depend upon the procedure and the mammal species involved. Restraint techniques can range from confinement in an enclosure through various types of physical restriction, to chemical immobilization. Any decision to use physical or chemical restraint in a research project should be based upon an understanding of the behavioural and physical characteristics of the species to be restrained, the field conditions under which the procedure will occur, the knowledge and skill of those persons handling the animals, the goals of the investigation, and the availability of appropriate equipment and facilities. Investigators must use the least restraint that is necessary to do the job in a humane and effective manner, with least stress to the animal.
Because many species of mammals are capable of inflicting serious injury to themselves or those handling them, some form of restraint is usually necessary. The well-being of the animal under study is of paramount importance and it must be emphasized that improper restraint, especially of frightened or stressed animals, can lead to major physiological disturbances, including hypothermia, hyperthermia, stress, shock and capture myopathy. In addition, the capture of some species of animals may alter their behaviour and predispose them to predation . Many species of mammals do not tolerate physical restraint and in some cases there is a great potential for animal or handler injury. Investigators should not allow unsupervised, inexperienced persons to handle any animal species until adequately trained to restrain, manipulate and release the animals properly. The specific handling characteristics of each taxonomic group is beyond the scope of these guidelines. The researcher should consult the current literature and experienced peers before handling an unfamiliar species. The following are general guidelines that must be considered when a researcher physically restrains a wild species:
Prolonged, distressful restraint should not occur. Administration of a tranquillizer or sedative to an animal that is physically restrained for longer periods of time may help to prevent injury to both the animal and the handlers. In some circumstances, it is advisable to use general anaesthesia for restraint in the field, particularly for larger or dangerous species. Invasive procedures may require some form of physical restraint initially, but usually require subsequent analgesia and/or chemical immobilization (see General Principles of Chemical Restraint Section).
The administration of anaesthetics to wild animals for restraint purposes can be accomplished safely; however, the use of chemicals do present risks to both animal and investigator. Field immobilization is almost always performed in less than ideal conditions. Only rarely can the investigator examine animals prior to anaesthesia, give accurate dosages in a controlled environment, and intensively monitor animals during anaesthesia events.
Although some wildlife projects may involve the use of oral or intravenous agents, most field situations utilizing chemical immobilization require the intramuscular administration of drugs. In some cases these are administered with a hand-held or jab-stick syringe to an animal which is physically restrained or confined. In other instances the drugs are given remotely with a projected syringe or dart. Drugs administered by projectiles can seriously wound or kill the target animal if a vital organ, a major blood vessel or a non-target area of the body is penetrated. Therefore, heavily muscled areas must be targeted when darting wild animals.
Researchers should be capable of monitoring an anaesthetized animal and providing general support measures should an anaesthesia emergency occur. Researchers must take great care in selecting a drug or drug combination for field use. Every anaesthetic agent has specific advantages and disadvantages, and there is no single agent that is suitable for the chemical immobilization of all mammalian species under all circumstances. Safe and effective drug dosages will vary with the species, age, sex and body condition of the animal. In addition, there can be individual and seasonal variations in the response to agents. It should also be realized that drugs used for wildlife immobilization have the potential to seriously affect both animals and humans involved.
It is essential the researcher and all field personnel be familiar with the consequences of drug exposure and be trained to take appropriate action in the event of an accident with animals or humans. The immobilization of wild animals should only be performed by trained personnel who have successfully completed a Ministry Chemical Immobilization Training Course (see Ministry Chemical Immobilization of Wildlife Policy).
There is tremendous taxonomic variation in the response to the pharmaceuticals used for chemical restraint, and dose extrapolation from one species to another should not be attempted. An outline of the numerous drug and drug combinations used for wildlife is beyond the scope of these guidelines. Detailed and current information on the recommended immobilization procedures for most North American species are published. Pertinent literature, experienced professionals, and the Ministry of Wildlife Veterinarian should be consulted before a researcher initiates a project involving the immobilization of wildlife species. Where possible, investigators should consider studies on the effects of new immobilization chemicals and procedures on captive individuals before incorporating them into field studies. (See Chemical Immobilization of Wildlife Manual).