HIGHLIGHTING A NEED FOR GREATER ANALYSIS OF STRONTIUM IN BONE FOR USE IN PROVENANCE DETERMINATION, ESPECIALLY FOR WILDBORN ZOO SPECIMENS AND ANALYSIS OF THE ISOTOPIC EFFECTS OF CAPTIVE DIET

Analyzing isotopes in bone has become standard practice, though the selection of elements varies. Carbon and nitrogen are typical, used to study herbivorous diets and trophic level respectively. But the often left out element strontium is highly indicative of provenance. Origin location is one of the most important pieces of metadata for an animal. As an animal grows, hard parts such as bones and shells create a record of diet through isotopic values. Environmental strontium ratios are reflected in bones and shells as those creatures consume from their environment. As environmental isotope ratios reflect regional bedrock geology, determining the exact location is nearly impossible. Still, a region of origin is useful information for research, especially in animals with regional differences.

Deceased zoo animals make up large portions of many museum collections, but the tag note “wild born” is not a substitute for location. More strontium isotope values would allow for geographic pinpointing, even helpful for researchers on a regional scale (e.g. Northeast, Southwest regions of America). Grey wolves in particular exhibit regional differences, though not to the extent of subspecies. These regional groups have names like Eastern grey wolves and Plains wolves. “Wildborn” specimens or those missing origin cannot be accurately places into these regional groups. Strontium isotopes need to be analyzed more in osteological museum specimens in order to assist researchers in determining provenance. Nuances in regional differences could be better studied with stronger location information. Furthermore, most zoo animals drink tap or well water same as the humans in the area, but oftentimes the food is imported, bringing a different isotopic signature. With more strontium data, these dietary effects could be better studied both in wild-born and captive-born zoo animals.