Orangutans, which are endangered and protected, are found on the islands of Sumatra and Borneo.  Their skulls are decorated and sold as tourist items. Credit: USFWS

MORPHOLOGY UNIT

The Morphology Section of the Laboratory uses the classic techniques of comparative anatomy to identify animal remains to species.  “Identifying the victim” is an essential first step in wildlife crime investigations, since the identity of animal remains must be established in order to determine which, if any, laws have been violated. 

For example, the Lab’s morphologists are routinely asked to answer questions like these:

• Is this carving made from walrus ivory or cattle bone?
• Is this fur coat genuine lynx or dyed rabbit?
• Are these feathers from trumpeter swan or domestic turkey? 

In each case, the first possibility would represent a serious violation of wildlife law, while the second would be a legal use of animal products.

The Forensics Lab employs expert morphologists in three taxonomically-based disciplines:

• Herpetology:  reptiles and amphibians. 
• Ornithology:   birds. 
• Mammalogy:  mammals. 

Every year, hundreds of thousands of birds die after becoming trapped in oil and other waste fluids associated with oil production. Morphology analysts identify these oil-covered bird remains to determine if protected species are being killed. Credit: USFWS

Each specialist is an expert in the evolution, taxonomy, biogeography, and functional morphology of their group.  In addition, the nature of forensic evidence requires additional specialized expertise.  For reptiles, this means expertise in leather identification; for birds, expertise in the macroscopic and microscopic identification of detached feathers is required; and for mammals, both expertise in microscopic hair identification and in determination of the species sources for ivory are needed.

To identify animal remains, the analysts in the Morphology Section examine the physical characters that are present in the evidence.  If the entire carcass is available, then all characteristics of body size, shape, and external markings can be documented.  Much more frequently, we are presented with partial remains:  a fragmentary skeleton; or a single feather; or a tuft of fur from the jaws of a trap; or a piece of reptile skin made into a watchband.  And in a high proportion of cases, we have no reliable data on the geographic source of the evidence, thus eliminating range information as a way of restricting the list of possible species.

Sea turtle skin (from their throat, neck and flippers) was once commonly tanned and used in the leather garment industry.  Commercial trade in sea turtle parts is now prohibited, though illegal trade still occurs.  Proper identification of sea turtle leather is important to wildlife law enforcement efforts. Credit: USFWS

The fragmentary nature of the evidence received at the Forensics Lab means that characters that form the basis for standard taxonomic keys are often not available.  Thus, it is rarely possible to determine complete dental formulae for mammal remains or scale row counts for reptiles. To meet this challenge, the Laboratory’s morphologists develop detailed knowledge of their taxonomic groups, and frequently document previously unreported characters that allow unambiguous discrimination between similar forms. 

For example, Lab mammalogist Bonnie Yates has discovered microscopic characters that are diagnostic for the hairs of the endangered Tibetan Antelope.  The antelope are killed for their wool, which is woven into the luxury fabric “shahtoosh,” threatening the species’ survival.  The hair identification technique can be applied to fabric with no data on area of origin and in the absence of any other morphological features, and has allowed the successful prosecution of dealers in Hong Kong, Europe, and North America. 

The endangered Tibetan Antelope.  The antelope are killed for their wool, which is woven into the luxury fabric “shahtoosh,” threatening the species’ survival.  Credit: USFWS

Initial examination and documentation of characters are followed by detailed comparisons between the evidence and reference specimens, or standards.  The verification of diagnostic characters with reference specimens or authoritative published data is essential to the morphological identifications made at the Forensics Laboratory.  Therefore, the vertebrate specimen collections of the Morphology Section are critical for our work.  In addition to the kinds of prepared skins and skeletons that would be found in the research collections of any natural history museum, we also maintain a variety of specialized collections tailored to the particular needs of wildlife forensics.  These include hair and feather samples mounted on glass slides for microscopic examination; collections of reptile leather and loose feathers; and collections of finished products that include verified examples of protected species.  These items range from sea turtle leather boots to Amazonian feather headdresses to walrus ivory carvings from Greenland. 

In addition to their identification work, Morphology Section staff members also conduct regular training sessions in the identification of animal parts and products for Fish and Wildlife Service staff, and serve as a resource for up-to-date scientific names and taxonomic information for the Office of Law Enforcement nationwide. This is a vital service because taxonomic changes may impact legal status, and because obsolete or incorrect names often appear on permits and other paperwork.  A collection of research papers and training materials prepared by the Morphology Section can be found at Publications and ID Notes. Specifically, please view our Morphology Publications, Feather Atlas, Ivory Identification Guide, and Morphology ID Notes and Guides.

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