Owl research may discover threats to humans
Dr. Mark Mitchell, director of the LSU Vet School’s Wildlife Hospital of Louisiana, has discovered that through evaluating the health of wildlife populations, he can in turn detect potential dangers to human health.
Mitchell and graduate assistant Nicole Lorenz are currently conducting a study to track owls rehabilitated at the hospital to determine their mortality once back in the wild.
Ten to 15 percent of the hospitals’ patients are raptors, or birds of prey, and the barred owl is the most common of those raptors.
“We have more access to [the owls] due to the volumes of raptors we treat,” Mitchell said.
Before the owls are released back into the wild they are fitted with a radio transmitted backpack. After eight weeks the owls are recaptured and a blood sample is taken. This is used to determine if the owls were exposed to any toxins or infectious diseases, such as the West Nile Virus.
Originating in Africa, the West Nile Virus is a new, emerging, infectious disease that first appeared in this country in dead crows along the East Coast in 1999.
Mitchell said he feels that the owls can serve as sentinels, or guardians, for the human population by supplying information about the spread of infectious diseases. Another reason the birds were chosen was they “habituate more consistently near human contact,” Mitchell said. This makes it more likely if anything harmful is found in the owls, it may be harmful to humans.
“[The owls] serve as great bio monitors,” Mitchell said. “It’s easier and more effective to track the birds instead of randomly testing soil in different areas.”
Since the study started eight months ago, one owl survived and another owl died after being released back into the wild.
“We do not know the cause of [the owl’s] death,” Mitchell said.
Five other owls have uncharacteristically dispersed, making it difficult to track them, Mitchell said.
Another threat to animal and human health is the presence of naturally occurring toxins in the environment. Mitchell and Dr. Peter Jowett of the Louisiana Veterinary Medical Diagnostic Laboratory at LSU are assessing the presence the heavy metals in the raptor’s blood they may have obtained from the environment.
“Large amounts of heavy metals can be hazardous,” Mitchell said. “When they leak into the environment they can affect reproductivity in animals and their natural behavior.
Another goal of Dr. Mitchell’s study is to identify the presence of antimicrobial resistant organisms in the environment. These organisms have developed a resistance to antibiotics.
Mitchell said the raptors serve as good indicators of antimicrobial resistance because, like humans, they are at the top of the food chain. If resistance occurs in the lower animals, it will likely accumulate in higher animals as well.
If resistance to antibiotics occurred in humans, it would “create bacterial monsters” without a way to treat them, Mitchell said.
According to Mitchell, 8 percent of the raptors treated at the hospital were found to be resistant to antibiotics.
“As an epidemiologist, I am interested in toxins and infectious diseases and the impact they have on wildlife and human health,” Mitchell said.
Mitchell is planning future projects using gopher turtles to continue to evaluate such organisms in their natural environment to detect any threats to human population.
The Wildlife Hospital of Louisiana is the only full-service wildlife treatment facility in the state.
Damiane Ricks