Field Mortalities in Wildlife Research
It’s Time for a Conversation

July 21, 2014
by Jon Geller, DVM, DABVP

Rocky Mountain Park, December 2011, NPS Research Project on Chronic Wasting Disease. Click to enlarge.  Dr. John Geller

If you happened to be driving up the road alongside Moraine Park in Rocky Mountain National Park in December of 2011, as I was, you would have been surprised to first note a coyote, and then a mountain lion, in plain sight in a meadow right next to the road. Shortly after, you would have come upon an elk carcass surrounded by large crimson patches of blood-stained snow. On closer inspection, you would have seen an injectable dart lying next to the carcass, containing remnants of carfentanil and xylazine. You might have become concerned since a few drops of carfentanil could be deadly to a child who might also be exploring the carcass, not to mention the magpie perched on the exposed sternum and the other scavengers and predators observed nearby.

Principal Investigators for government-funded field research projects must submit proposed studies to the appropriate Institutional Animal Care and Use Committee, or IACUC, to ensure compliance with the Animal Welfare Act. Unfortunately, unlike institutional animal research, there is no protocol for project inspection or follow up, often leading to unfortunate outcomes that may not be reported. Unforeseen anesthetic complications, intra-species transmissions of disease, adverse effects of outdated and AWA-noncompliant protocols, and participation by underqualified and under-skilled personnel coalesce to prompt a call for an extensive review of IACUC protocols related to wildlife field research.

Mid-abdomen shot in Rocky Mountain Park. Click to enlarge.  Dr. John Geller

According to National Park Service reports1, a rafter floating down the Colorado River through the Grand Canyon in August 2012 would have been surprised to see several wildlife biologists in a motorized dory taking aim at a Desert Bighorn sheep grazing along the riverbanks. The rafter would not have heard the dart bite into the sheep’s skin and underlying muscle, but would instead have seen the sheep buckle to her knees and then collapse into recumbency. They would have witnessed a frantic effort on the part of the biologists to resuscitate the sheep, unfortunately, without the assistance of the attending veterinarian who was supposed to accompany them. The mis-aimed dart had penetrated the sheep’s abdomen, causing hemorrhage and death. The biologists had not yet secured approval for their research project, resulting in an immediate shut-down and investigation once the Park authorities were notified of the fatality. A year later, the same PI and dart shooter were allowed to recommence their project—without consequences, tighter controls or follow up.

Several capture methodologies that have been used for years require further scrutiny, because they both are ineffective and cause pain and suffering. Fans of quantum physics (aren’t we all?) are aware that the mere act of studying subatomic particles changes those particles’ behavior2. That principle applies to wildlife research subjects as well. For example, leg-hold traps used in wolf studies have evolved to include padding, triggered sedatives (phenothiazines), and remote notification of researchers in order to decrease wolves’ time in the trap. Many of the wolves are then radio-collared to study their future movements and migrations. However, trap refinements are of no benefit if the wolves under study alter their behavior, daily migrations, and travel patterns as a result of the disrupting trap-line.

Electro-fishing is popular among fish biologists and veterinarians studying fish because the resulting shock temporarily stuns all fish in the area, allowing collection of the species under study. Unfortunately, radiographic studies are showing a high number of vertebral fractures—due to the violent axial muscle contractions—causing permanent impairments. Further discussion is needed about whether this methodology complies with the AWA.

Restraining a sedated bull elk in Rocky Mountain Park.  Dr. John Geller

Many wildlife research projects involve powerful sedatives and tranquilizers with complex physiologic effects. In many cases, however, a qualified wildlife veterinarian is not present, sometimes resulting in significant morbidity and mortality. These adverse outcomes could be minimized if someone with the anesthesia training and knowledge of pharmaceutical effects on physiology had been present. IACUC’s could require that a wildlife-qualified veterinarian be present for all field anesthesia of large or endangered mammals.

The argument for putting a temporary halt to wildlife research proposals could not be stronger than in cases where man-made disease is inadvertently introduced into a population, resulting in out-of-control spread, transmission, and potential species collapse. In the late 1960s and early 1970s, researchers at Colorado State University and the Colorado Division of Wildlife collected large numbers of white-tail deer from various locations and placed them in pens in the foothills west of Fort Collins. The result, 40 years later, is unstoppable transmission and increasing incidence of Chronic Wasting Disease, now affecting deer, moose, and elk in 15 states and seven provinces of Canada. There is no current treatment or prevention. In the words of one prominent epidemiologist with the Centers for Disease Control Prevention, “I have no doubt that Chronic Wasting Disease is a man-made disease.” In his opinion, CWD was most likely introduced into this deer herd by cross-species transmission and modification of scrapie from sheep that previously inhabited the pens.

Field studies, as opposed to field research projects, gain summary IACUC approval because they presumptively do not cause pain or distress, or significantly alter the behavior of the animals being studied, and are Intended to be mostly observational in nature. Because of their potential effects on behavior and stress levels, field studies may not be as benign as depicted.

Captive bison herd at CSU Foothills Campus following rabies outbreak.  Dr. John Geller

If you were near the bison pens in the Foothills west of Fort Collins, Colo., on May 12, 2012, you would have noted a skunk wandering erratically in the pen, just as the animal caretaker did. Captive wildlife are not immune to researcher and IACUC oversights. USDA-APHIS investigators involved in a 2012 embryo transfer project with captive Yellowstone bison failed to vaccinate the herd after numerous skunk rabies confirmations in the area, and the disoriented skunk was found wandering in the pen. Three weeks later, three of the bison dropped dead, two with confirmed rabies after brain histopath. The third bison was never necropsied.3,4

It’s time for a conversation. The veterinary profession should collaborate with the Wildlife Disease Association, the American College of Zoological Medicine and other professional wildlife organizations to brainstorm refinements to the wildlife research project approval, inspection, and follow-up processes before more damage is done. An umbrella group could be charged with expediting collaboration among existing IACUC’s to accomplish this task. Let’s slow things down so we can get it right. Pending proposals for field research projects should be triaged or put on hold until these issues are addressed. The HSVMA can be an important voice in getting this accomplished.



  1. Briefing Statement, National Park Service IACUC, Sept.6, 2012,
  2. Hawking, S., Mlodinow, L., “The Grand Design”, Random House, New York 2010
  3. Larimer County Colorado Dept. of Health and Env. News Release, June 29, 2012
  4. Rhyan, C., Van Campen, H. et al, Rabies Deaths in Two Bison, Case Rep Vet Med. 2013;2013(0):906782. 1-3. 8 Refs

Dr. John Geller

Dr. Jon Geller graduated from Colorado State University College of Veterinary Medicine in 1995, and currently works full time as an emergency veterinarian and hospital director at Veterinary Emergency and Rehabilitation Hospital in Fort Collins, Colo. In 2009, he became certified by the American Board of Veterinary Practitioners in Canine and Feline medicine. In 2010 he joined the National Park Service as a member of their newly-formed IACUC committee, and also worked as a volunteer veterinarian on several field research projects with elk. He has participated with HSVMA with several RAVS trips, including international projects to help start a surgical and emergency training program for veterinarians in Mexico.