What is Causing the Decline of Bobwhite Quail in West Texas?
For generations, the whistle of the Northern bobwhite has been an iconic sound in the Rolling Plains region of Texas. However, in 2010, a mystery began to unfold across millions of acres of Texas grasslands. Despite ideal rainfall and lush habitat, quail populations failed to rebound as expected, remaining as low as in drought years. This population decline led to the launch of Operation Idiopathic Decline.
At the Texas Tech University Wildlife Toxicology Lab, our researchers stepped into the field to solve this ecological puzzle. We discovered that the culprit wasn’t just the weather or habitat loss; it was also a silent, widespread epidemic of parasitic infections that left the birds vulnerable and struggling to survive.
The Hidden Culprit: A Closer Look at the Quail Eye Infection
Through years of rigorous wildlife toxicology research, our team identified a one of the primary drivers of the documented population crashes: the parasitic eye worm Oxyspirura petrowi.
Relative to the quail, these parasitic worms are far from “tiny.” An adult female eye worm can grow to be as long as the diameter of a penny, and dozens of worms can be found in a single quail eye. In a human, this would be the size equivalent of having dozens of toothpick-sized worms crawling behind the eyeball. These parasites reside in the Harderian gland and tear ducts, where they feed on blood and can cause severe inflammation, corneal scarring, and hemorrhaging.
For a wild bobwhite, clear vision is a matter of life and death. We found that birds suffering from heavy eye worm infection often lose their ability to detect predators such as Cooper’s hawks or to navigate their environment. This explains the heartbreaking reports from ranchers of quail flying full speed into stationary objects like barns, fences, and even parked trucks.
The Role of the Cecal Worm in Quail Decline
While the eye worm captures headlines due to its visibility in harvested birds, the Department of Environmental Toxicology also uncovered a secondary threat: the cecal worm, Aulonocephalus pennula. Found in a portion of the lower digestive tract called the ceca, these parasites were present in up to 90% of the birds sampled in the Rolling Plains.
High cecal worm burdens steal vital nutrients from the quail, leading to weight loss, muscle emaciation, reduced fat stores, and thus, reduced energy. This makes it significantly harder for the birds to survive the winter or successfully raise a brood during the breeding season. Together, the eyeworm and cecal worm create a dual assault that can decimate a population even when the Texas habitat is perfect for quail.
A Science-Backed Solution: QuailGuard®
The mission of the Wildlife Toxicology Lab is not just to document decline, but to find a solution. After over a decade of research and collaboration with the U.S. Food and Drug Administration, Dr. Ron Kendall and his team developed QuailGuard®, a medicated quail-specific feed containing fenbendazole, an anthelmintic.
This breakthrough represents the first FDA-approved medication for wild quail available to the public. In field trials on demonstration ranches, we have seen sustainable quail populations grow by as much as 500% after suppressing these parasitic infections. By breaking the cycle of infection spread by intermediate hosts like crickets and grasshoppers, we are giving the bobwhite a fighting chance to reclaim the Rolling Plains.
Join the Mission to Save the Bobwhite Quail
The survival of the northern bobwhite is vital to the culture and economy of West Texas. At the Texas Tech Wildlife Toxicology Lab, we are committed to using world-class science to protect our natural heritage.
We invite you to be a part of this success story. Whether you are a landowner interested in distributing medicated feed or a conservationist looking to support our ongoing research through a donation, your involvement makes a difference.
Contact the Texas Tech Wildlife Toxicology Lab today to learn more about our research or to find out how you can contribute to the recovery of Texas quail.
