Disappearance of bovine fetuses in northwestern Wyoming

Brucellosis is a bacterial disease of cattle that has become established in elk (Cervus elaphus nelsoni) and bison (Bos bison) of the Greater Yellowstone Area. It causes pregnant elk and bison to abort, and the aborted fetus has the potential to transmit the pathogen to disease-free domestic cattle. We examined how long healthy bovine fetuses, as surrogates for aborted bison or elk fetuses, remained in the environment and could be available for contact by elk, bison, and cattle. Disease-free bovine fetuses were placed on Wyoming's National Elk Refuge, state of Wyoming elk feedgrounds, and Grand Teton National Park to simulate aborted elk or bison fetuses. We monitored the fetuses until they disappeared due to scavenging. Fetuses disappeared on average in 26.8 hours (SD=25.3 hours) from the National Elk Refuge, 40.7 hours (SD=31.1 hours) at state elk feed-grounds, and 57.5 hours (SD=48.0 hours) at Grand Teton National Park. Ninety percent of fetuses can be expected to disappear from the National E...