Research on bobwhites in Texas might hold promise for the future of the species.
[by Ronald J. Kendall, PhD]
My interest in wild bobwhite quail began when I was growing up in South Carolina, being mentored by my grandfather. He was an avid outdoorsman and had particular fondness for quail hunting and bird dogs. Following him through the fields and quail coverts of the Carolina Lowcountry made me want to also follow in his footsteps as a hunter. Over the years, my interest in bobwhites grew to include their ecology. I’ve made the study of Colinus virginianus my life’s work.
In the 1960s and for decades prior, quail hunting opportunities in South Carolina and throughout the bird’s range were nearly unlimited, but they’re now diminished so that it’s hard to find even a single wild quail in the Palmetto State. In fact, since the 1980s, bobwhites have been reduced, if not eliminated, from more than 90 percent of their original range. Among many theories of their decline, the most widely accepted is habitat degradation associated with urban sprawl, dramatic changes in agricultural practices, and greater difficulty in implementing quail-friendly land-management practices, such as prescribed burning. Along with that, predators that feed on quail have grown in number, particularly raptors, and others—feral hogs, coyotes, and armadillos, for example— have increased their range. The traditional practices of habitat management—planting food plots, prescribed burning, and even predator management, particularly controlling raccoons and skunks—have not been able to reverse the dramatic drop in bobwhite numbers.
Yet during the decades of the birds’ demise, researchers and land managers kept preaching “habitat management.” People just accepted it. Prior to this decade, most scientific studies of quail addressed either habitat loss or management, and possibly predators.
Texas is home to some the last significant populations of wild bobwhites in the United States. In my opinion, the Rolling Plains ecoregion of West Texas represents the Alamo of wild bobwhites and the hunting of them in the United States. If we’re ever to restore wild populations, maintaining quail in Texas is imperative to not only Texas but also the rest of the country. If the habitat ever returns throughout the bobwhite’s traditional range, Texas is about the only place where wild bobwhite populations are healthy enough to sustain a program of trapping and transplanting, similar to the methods used to restore wild turkeys.
In the last decade, Texas suffered a sudden loss in wild bobwhites. As a result, some of the research we’re doing here in Texas might be shining light on other factors that contributed to the widespread loss of wild bobwhites.
IN 1997, AFTER NINE YEARS AT CLEMSON UNIVERSITY, where I was a professor of environmental toxicology, I took a position at Texas Tech University in Lubbock and was tasked with establishing a research institute and an academic program in the same discipline. One of the most attractive reasons for relocating to Texas from my home state was in fact the wild bobwhite quail hunting that the recruitment team talked up. I accepted the job offer.
In fall of 1997, in Borden County, which is part of the Rolling Plains ecoregion, I experienced some of the finest wild bobwhite hunting in my life. Soon thereafter, I purchased property southeast of Lubbock in Kent County. The place had great quail habitat and a healthy number of coveys. In early 1999, I established Big K Ranch, Ltd., which has served as my own field laboratory for wild bobwhite quail management, conservation, and hunting.
For 11 seasons, I had great hunting on the ranch. One memorable day my son, Ronnie, and I hunted one draw with a single setter. We moved 17 coveys of wild bobwhites in 90 minutes.
Heading into the fall of 2010, we expected another great year. That summer had brought good rains, which helped produce perfect habitat and so many quail broods that we worried we’d run over them. The operational phrase was “Drive slow and watch where you are going.” Neighbors and fellow quail hunters from around the Rolling Plains also predicted a phenomenal hunting season. It did not materialize.
By August and September, our ranch manager, who was on the property daily, began noticing fewer and fewer quail, and by October, it was hard to find one at all. We had beautiful habitat—food and cover—including sunflowers, broom weed, and ragweed—but no wild quail. That is when I crossed a bridge in my scientific thinking. I began to believe that something other than loss of habitat had been contributing to the decline of quail.
After the decline in 2010 across the Rolling Plains, which is an area approximately the size of Michigan, several subsequent hunting seasons were literally lost. This reversal of fortune, however, precipitated a large research study called Operation Idiopathic Decline (OID), which represented the largest quail-disease study ever supported in the United States. Key organizations, including the Rolling Plains Quail Research Foundation, Park Cities Quail Coalition, and Texas A&M University AgriLife Extension Service, put up funding to move OID forward. The operation comprised researchers from multiple universities who investigated viruses, bacteria, environmental contaminants, and parasites in wild quail across the Rolling Plains ecoregion of West Texas.
After thousands of work hours trapping, handling, and evaluating thousands of wild bobwhites, we concluded that parasitic infection was the most plausible cause of the die-off. We were particularly interested in two parasitic nematodes, the eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula).
In March 2012, Rick Snipes, then president of the Rolling Plains Quail Research Foundation, asked me to take a leadership role in the research. This led to the establishment of the Texas Tech Wildlife Toxicology Laboratory (WTL). I took the position of leading the lab and transferred out as director of the Institute of Environmental and Human Health and chair of the Department of Environmental Toxicology.
Now, nearly eight years later, the WTL has conducted thousands of hours of fi eld and laboratory research on parasitic infection of bobwhite quail. Our work has essentially allowed us to follow the science of parasitic infection, and to date, we have published more than 40 peer-reviewed research papers— many more are on the way through the findings that are being generated from our productive and very hardworking laboratory team. We have learned so much since we began this journey and we have more to uncover, but the scientific revelations that have unfolded are astounding.
THE PARASITES WE FOUND IN TEXAS QUAIL ARE CALLED HELMINTHS, or parasitic nematodes. We discovered that the eyeworm and caecal worm infect wild quail through an intermediate host, including certain species of grasshoppers, crickets, and beetles, which ingest parasite eggs passed in the feces of wild quail. In the intermediate host, the larvae develops to L3 larvae, which is the infective stage, in a matter of weeks. In turn, quail ingest the infective larvae when they eat these certain species of insects.
For the eyeworm, the L3 larvae exit the insect in the crop of the quail, migrate up the esophagus into the nasal sinus, and then into the eye compartment, where the larvae feed and grow to adults in just a few weeks. An adult female eyeworm in a bobwhite may be large enough to stretch across a penny, and they are egg-laying machines and may contain thousands of eggs, which ultimately are passed through the bird’s GI tract via feces, making the eggs available to the insects—which explains why these infections can spread so quickly once wild bobwhites are infected. In fact, in one of our fi eld studies, we had data showing relatively low infection rates in wild bobwhites that emerged into a pandemic, with more than 90 percent infection rates, in just a matter of weeks.
We now realize that the eyeworm is a long-lived organism that likely remains in the quail’s eye up until the death of the bird. Once infection levels exceed 20 eyeworms, we see extensive damage, particularly in the ducts in the rear of the eye. In our fi eld collections, we have noted that infection levels of 40 adult eyeworms in a quail are rare because birds usually die, either from infestation or predation, before that number can accumulate.
We have investigated the molecular biology of the eyeworm and have determined that it is 96 percent related at the DNA level to the Loa loa, an eyeworm of Central Africa that can infect and can cause blindness in humans.