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APPENDIX 2
OBSERVATION AND COLLECTION OF MAMMALS

Whether as a layperson or as a professional scientist, the observation and collection of mammals can be an exciting occupation. Below we have outlined some methods commonly used in these endeavors. Prior to getting started with your observation or collecting project, several factors should be considered. First, be cognizant of any permit that might be required. In most cases, permits can be obtained through the Texas Parks and Wildlife Department (TPWD); however, federal permits through the US Fish and Wildlife Service may be required in some instances. Second, be knowledgeable of state and private properties relative to permission for access. Third, be cautious, as many species of mammals can carry a variety of wildlife diseases that are transmittable to humans (e.g., rabies, plague, and hantaviruses). The Centers for Disease Control and Prevention has literature available relative to zoonotic diseases and safe handling procedures. In addition, there are scientific articles that address this issue (in appendix 3, see Kelt et al. 2007, 2010; Mills et al. 1995a, 1995b, 2002). Fourth, be knowledgeable of guidelines concerning the proper and ethical methods of collecting mammals (see Sikes et al. 2011). Fifth, if you are an amateur collector, we encourage you to consider depositing your collection with an accredited natural history museum. Although no one would question a private collection of the occasional skull for personal enjoyment, extensive collections should be made available to the scientific community. Most natural history museum personnel would be pleased to assist in providing conservation-quality materials and direction for obtaining scientific data associated with the specimens.

If questions arise concerning any of these or other factors pertaining to observing and collecting mammals, you might consider contacting TPWD personnel or biologists employed by state colleges or universities. These individuals will be knowledgeable and generally would be eager to assist you in your endeavors.

OBSERVATION OF MAMMALS. Practically all that is needed to make interesting and useful observations of mammals is a good pair of binoculars and the inclination to rise early and stay late. Unlike birds, most mammals are either crepuscular (twilight active) or nocturnal (night active) in nature, making prolonged observation of behavior, feeding habits, and other aspects of natural history more difficult. Additionally, many species are fossorial (dwell underground) and cannot be directly observed except during the rare and brief moments these animals may appear at their burrow entrances or are dispersing from the maternal burrow. Finally, many species occur in our bays and oceans and require access to either a boat or airplane to observe, unless they strand on our beaches.

The observation of mammals is often done indirectly by evaluating the tracks, scats, scrapes, rubs, and other such sign that mammals leave behind as evidence of their activities. Locating sign and drawing accurate deductions of animal activity is an art that for the most part has been lost as people rely less and less on understanding nature to fulfill basic needs. Nevertheless, reading sign is a fascinating occupation, many aspects of which can be learned simply through interest and perseverance. Acquiring one or more of the numerous field guides or referring to Internet websites now available on this subject will speed up the learning process and allow for a more complete understanding of the outdoors.

COLLECTION OF MAMMALS. For scientific purposes, collections of mammals are needed. The collection and the subsequent preparation as museum specimens is a complicated process that often requires a great deal of equipment and planning. Numerous techniques and types of traps are available, depending on the animals to be taken, the region studied, and the type of information being sought. For smaller mammals, such as mice, mouse traps of the variety that snap shut on the animal can be purchased in almost every hardware store; however, the larger Museum Special trap is best because the wire that strikes and kills the mouse is far enough from the treadle to keep the head of the mouse from being struck and crushed. For study purposes, broken skulls are less desirable than unbroken ones. Several types of live traps are available for purchase or can be built with minimal instruction. These live traps are effective for capture–mark–release studies that allow for long-term observations.

The still larger rat trap is stocked in most hardware stores and is suitable for taking animals the size of woodrats and small ground squirrels. Steel traps in sizes 0 to 4 are used in many areas to secure other animals. Macabee gopher traps are the best yet devised for taking pocket gophers. Several mole traps are on the market; the stabbing variety is preferred by most collectors. Some live traps for gophers are available.

Many specimens are most effectively taken by firearms. For smaller and medium-sized mammals, a shotgun is recommended, but shot of small size should be used to avoid unnecessary mutilation of the animal. Nets of silk or nylon may be useful to the mammal collector, especially in capturing bats. Pitfall traps are often set for shrews by burying a can up to the rim in mammal runways and other likely spots.

In addition to traps that kill the mammal, numerous styles and sizes of live traps are offered for sale by various manufacturers. These include the popular Sherman live trap, frequently used for mouse- and rat-sized mammals, and the equally popular Havahart traps, useful for capturing raccoon-sized mammals. Large drive nets, drop nets, and similar traps, often used in conjunction with other equipment such as helicopters and immobilizing drugs, are used by specialists to capture larger mammals for study, such as deer and elk. Properly preparing mammals as museum specimens requires skill, patience, and training. The labeling, skinning, and stuffing of mammal skins, as well as the preparation of skeletal material, are demanding, sometimes tedious tasks that require attention to detail and a lot of practice. Several handbooks and guides are available to introduce the mammal enthusiast to this necessary aspect of mammalogy.

For safely storing prepared mammal specimens in accessible fashion, a museum cabinet that excludes insects, dust, and light is essential. A visit or a letter of inquiry to the nearest museum known to maintain a collection of study specimens of mammals will yield all needed information about the type of container best suited to the needs of the collector. Advice concerning the preparation of mammals as specimens, including the preparing of skins and cleaning of skeletal material, can be obtained from the same sources.

The trapping of mammals, even for scientific purposes, requires a scientific collecting permit. Every state has its own laws relating to hunting and trapping, and the collector should obtain and read the applicable laws so as to carry on collecting in conformance with the law. In Texas, scientific collecting permits are issued by the TPWD; advice and clarification on collecting regulations can also be obtained from that department. Collecting on federal lands, such as national parks and monuments, requires a permit from federal authorities. Government personnel at the site to be studied should be contacted for information on obtaining federal collecting permits. Of course, if mammal collecting is to be done on private lands, the permission of the landowner also is required. Next to conducting mammal collection and observation activities in a lawful and responsible manner, the most important obligation of the mammalogist is to take accurate and complete field notes. Only in this way can new information eventually be provided for the benefit of others. Field notes can usefully be divided into three sections: a catalog of specimens, a field journal, and accounts of species. For convenience, all three sections ordinarily are kept in a single binder, but separate binders may be used. Enter the name of the collector and the year in the upper left-hand corner of every page but far enough from the margin to permit binding of the pages. Each page should be filled before another page is started. Write full notes, even at the risk of entering much information of seemingly little value. One cannot anticipate the needs of the future when notes and collections are processed. The following are suggested topics, but do not restrict yourself to these alone. Be alert for new ideas and new facts. Special data sheets may be helpful.

SPECIMEN CATALOG. In the specimen catalog (see figure below) all specimens of vertebrate animals should be given consecutive numbers. Never repeat a number; for instance, do not begin a new series each year. At least one line of each entry should be devoted to the precise locality. Begin this line with the country, if applicable, followed by the state, county, and precise locality description. If possible, use a global positioning system to determine the exact universal transverse Mercator coordinates for each specimen collected. Also include airline distance and direction from some well-established town as well as elevation, county, and state. After the locality data, describe each specimen. The description should include the scientific name, sex, and standard measurements of the specimen. Use the vernacular name of the species if you are not sure of the scientific name. If not a conventional specimen, indicate the nature of the preparation type, whether it is, for instance, a skeleton, the skull only, the skin only, or in alcohol. Toward the end of the line it may be desirable to enter, on occasion, the color of iris and soft parts.

Given the advent of modern techniques and disciplines such as molecular genetics, toxicology, epidemiology, zoonosis, and archival natural history research, it is crucial to collect tissue or blood samples. A special number (referencing the tissues and karyotypes) should be assigned to these samples and recorded in each catalog entry, as shown in the illustration. It is recommended that samples of heart, liver, kidney, spleen, lung, muscle, and blood be obtained from each specimen. These samples should be frozen in the field on either dry ice or liquid nitrogen and stored long term, preferably at −80°C or colder. The value of such tissue collections is only now being realized, and it is expected that their value will only increase in the future.

Specimen catalog

Figure 368. Example of a specimen catalog page.

FIELD JOURNAL. On the first line of the field journal enter date and locality. Follow with a concise account of route and travel area and habitats studied and record number and kinds of traps set, distance between traps, number of vertebrates collected, as well as other pertinent information. For example, record the number of traps set in each type of vegetation and numbers and kinds of animals caught therein. Describe vegetation (saving plant-press samples of species not positively known), nature of ground, slope, exposure, and drainage in each belt of animal life sampled. Describe the exact location of trap lines, referring to your topographic maps, and also enter a sketch, in profile or surface view or both, to illustrate the locations and relations of the different habitats crossed. Properly marked maps for each region worked should ultimately be bound in with the field notes of at least one member of your field party.

Keep a record of distance between traps, area covered, and results of each night's trappings; give the number and type of traps put out in each habitat and number of animals of each species captured in each habitat (whether or not preserved). It is advisable to record the sex, age, and breeding condition of each animal. Special data sheets are helpful.

Keep a full record of breeding data, including number and approximate size (crown–rump length) of embryos or of young found in nests. Dig out burrows if practicable; make drawings to scale, plan, and elevation; describe fully.

Record food plants; keep specimens for identification when not known by a definite name; preserve contents of cheek pouches and stomachs. If contents are not saved, identify and record the contents.

Note regularly in notebook all ancillary finds, that is, odd skulls or fragments of animals of whatever sort or source, serially numbered along with specimens of the more usual sort. Give full information, as with odd skulls secured from trappers. Label all such specimens adequately, as elsewhere described. Keep frequent censuses of diurnal mammals, with habitat preferences indicated. These censuses, if short, need not be entered on formal census sheets. When leaving a well-worked locality, enter a summary of species observed, with remarks of a general nature, such as those that relate to local conditions of terrain, human activities, and other pertinent conditions.

Where feasible interview residents, trappers, state wildlife biologists, and national forest or park rangers at each locality visited. Always record accurately the name, official position, or occupation and address of each person giving information; give also your opinion as to his or her reliability. Note general attitude of person interviewed as to game laws, conservation, and effects of settlement by humans and record specific comments, complaints, and criticisms. Ascertain present numbers and distribution of large mammals as compared with former status. As far as possible, get definite statements expressing ratio of abundance now to abundance a definite number of years back. Seek such information when feasible by indirect query; do not risk influencing your informant's statements with leading questions. Record fully all evidence as to human influence on original or natural balance. Record present economic relations of vertebrate animal life (that is, the effect on agriculture and stock raising) with full details. Note opinions of persons interviewed as to whether species should be protected or destroyed. Describe local methods of capture or destruction; give your opinion as to their effectiveness and justification.

Opportunity offering, record detailed observations on the effects on mammals of severe storms; floods; forest, brush, or prairie fires; overgrazing; tree cutting; road building; or tree planting.

SPECIES ACCOUNTS. Accounts of species should be headed with either the scientific or common name, as preferred. The date and locality for the account should be given on the first line. Only one species should be written about on a single page. Include not only facts but also interpretations and generalizations. The accounts should be written in a style suitable for quoting in any publication. Accounts of species need not be restricted to those collected. If the account is about animals collected, it is wise to refer to the animals by your field numbers.

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From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.

Natural Science Research Laboratory