Handling and Care of Dry Bird and Mammal Specimens
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Conserve O Gram September 2006 Number 11/9 Handling And Care Of Dry Bird And Mammal Specimens Introduction Organization Natural history specimens represent the bio- logical legacy of our predecessors. They are the Taxonomic arrangement tools used by researchers to assess how species are distributed in geographical and ecological There are a variety of schemes to organize bird time and space. How we care for these collec- and mammal specimens. They can range from tions today will directly affect their significance following a fully phylogenetic arrangement that and usefulness in the future. Some bird and organizes taxa to the subspecific level based on mammal specimens in North American collec- a recognized taxonomic authority to a simple tions are over two hundred years old. All speci- alphabetical arrangement by family or genus. mens, new or old, share common preservation The system followed should be logical, intuitive, and maintenance needs. The handling and care and efficient, and should allow researchers to of dry bird and mammal skins, skeletons, and easily find specimens of interest. Not all users parts is highlighted in this Conserve O Gram. of natural history collections are knowledgeable systematists, so base the scheme on how the Storage collection will be used and by whom. Always document the arrangement of the collection A well-sealed cabinet is the best protection and post a copy handy for researchers and staff. for bird and mammal specimens. The cabinet shields specimens from UV light, dust, pollut- Physical arrangement ants, insect pests and rodents, and moderates ambient temperature and relative humidity. Study skins of birds and mammals are gener- Always return specimens to the cabinet after ally placed directly in drawers or compartmen- use and close the doors after removing or talized in trays within drawers. Specimen trays installing specimens. Never leave the speci- provide a convenient way to sort specimens mens outside the cabinet overnight. Doing by sex, locality, species or subspecies. They so can expose them to damage by rodents or make it easier to remove a series of specimens insect pests such as clothes moths and dermes- at a single time for examination. All materi- tid beetles. Returning an infested specimen als should be “archival or museum quality”, a to a cabinet will expose the entire contents term connoting permanence and durability but to a potential insect infestation. For suitable for which there is no universally agreed-upon sources of vertebrate cabinets see Conserve O meaning (Cato et al. 2003). Ideally, drawers Gram 4/10. (if no trays are used) and trays should be lined National Park Service Conserve O Gram 11/9 Conserve O Gram 11/9 National Park Service with unbuffered cotton blotter paper. This and “Covers” in Rose and Torres (1992). serves a variety of functions including reduc- ing movement of specimens when opening Bird eggs and nests: Eggs need protection and closing drawers, absorbing grease and oil from breakage and to ensure they do not roll. still remaining on the skin and thus prevent- Use polyester batting to wrap each egg and ing the staining of trays, and improving the then place in a box lined with polyester or museum staff’s ability to see specimen damage cotton batting for additional protection. Nests or insect frass resulting from an insect infesta- can be stored in boxes made of clear polysty- tion. Small birds such as hummingbirds are rene or archival board. See-through boxes or often stored in round plastic tubes due to their those with Mylar® windows are practical for fragile nature. Flat skins and tanned hides of viewing the contents without opening the con- large mammals such as mountain lions and tainer. For additional protection use a layer of foxes should be stored flat in drawers. A less polyethylene foam to line the bottoms of the preferable but more common practice is to nest boxes and secure each nest with a “ring” hang skins over padded support bars with the of unbuffered blotter paper. Other sugges- weight supported evenly. This can cause skins tions are found in Cato (1986). Eggs and nests to stretch no matter how much care is taken are usually stored separate from the skin col- with the skins. lection. Mounted birds and mammals are usually Skulls and skeletons (osseous material) are stored separate from the dry skin collections. generally stored in vials or boxes. Vials can be They typically require more storage space due made of glass or polyethylene plastic (there to their irregular shape. If they are placed on are pros and cons to both), and can be round drawers in cabinets they will need additional or square (the latter shape prevents rolling). support to keep them from toppling over After prolonged exposure to some chemical when the drawer is opened. Frequently, they fumigants i.e., paradichlorobenzene (PDB), are stored on stationary shelves or specially vials made of polystyrene have been known to designed racks that accommodate differ- show signs of “crazing”, a type of deteriora- ent sized objects. If stored on open shelves tion that forms very fine cracks in the surface they should be protected with dust covers of the vial. Polyethylene caps or archival made from materials such as cotton or poly- foam rod plugs are preferred covers for vials ethylene sheeting. The dust covers protect- over corks because they reduce the amount of ing open shelving mount storage should be acidic wood products in natural history collec- opaque to add protection from light. Antlers tions. Containers should be large enough that and mounted heads of deer and elk can be specimens can be removed and replaced with- suspended from heavy gauge hardware cloth out damage. Bird skulls traditionally remain using padded supports. Do not drill holes in inside the skin; whole bird skeletons usually are the specimen to anchor it to support brackets stored separately from the skins to conserve because of the irreparable damage it causes. If space. The skins and skeletal components of space and materials are available, however, it mammals are usually stored together but in is preferable to store these specimens on open separate trays. A series of vials can be stored shelving or in closed cabinets. See additional in trays that either fit within the skin tray (but suggestions listed under “taxidermy mounts” not on top of specimens) or just outside the 2 Handling and Care of Dry Bird and Mammal Specimens Handling and Care of Dry Bird and Mammal Specimens 3 National Park Service Conserve O Gram 11/9 Conserve O Gram 11/9 National Park Service tray. To keep vials from rolling in a tray, use specimen and support the rest of the specimen stable non-acidic products such as polyethylene with the other hand. The skins of small birds foam, not wood blocks or cork. The skulls and or those with long or very fragile legs are also skeletal elements of large mammals should be sometimes prepared with a support stick in stored in boxes or trays or on padded shelves. the middle of the body to provide extra sup- The cranium and mandible of the skull should port. Handle these birds by the support stick not be stored with the teeth in direct contact but because the stick is anchored into the skull. because this can cause breakage of the teeth. Take care not twist or twirl the specimen by It is preferable to store the skull and mandibles the stick as this can loosen the anchorage point with the teeth facing up; if stored so that the of the stick. Handle wings carefully taking teeth occlude, separate them with a padded care not to slide a wing along a surface against layer of polyethylene foam. the grain which might damage the feathers. Never handle specimens by the tags or labels. Handling After returning specimens to a cabinet, be sure Wearing gloves reduces the transfer of oils there is enough space between the top of the and dirt from individuals to specimens and specimen and the bottom of the drawer above vice versa. Cotton gloves are suitable when before sliding in the drawer. Tips of ears of handling recent collections but when handling some rodents are prone to sticking up and ears older specimens, those collected before the of lagomorphs (rabbits and hares) are espe- 1970s, latex or nitrile gloves are recommended. cially high and can be easily broken when slid- The insides of skins of many older specimens, ing in a drawer with inadequate clearance. particularly taxidermy mounts, were treated with arsenic and other insecticides, or pesti- Mounted specimens of birds and mam- cides and fungicides i.e., mercuric chloride, that mals are awkward and can be heavy to handle can leach through the cotton fibers, making alone. Ask for help when moving a large latex and nitrile a better choice. Research- mount and use carts with support straps when ers are required to wear gloves when working possible. Wear gloves when handling older in NPS collections, but for many non-NPS (collected before the 1970s) specimens because natural history collections there are no restric- of the past practice to treat the insides of skins tions. If gloves are not worn, wash your hands with arsenic or other chemicals to repel insect before and after handling any specimen. pests. Skins: Handle bird and mammal skins one at Bird eggs and nests: Due to the fragility of a time by placing your hand around the main eggs, some museums allow them to be handled part of the body. Do not grasp the extremi- only in the presence of a curator or collection ties or other fragile parts of the body.