Probably one of the most frustrating things in the field of wildlife management has been the spreading of misinformation regarding Chronic Wasting Disease (CWD). Currently, everyone from rock musicians to T.V. hunters are telling the general public that CWD either isn’t real or isn’t a big deal. Meanwhile, the consensus among wildlife professionals is that CWD IS a big deal. Opinions differ among how we actually deal with the disease, but recognizing that it is the most important disease issue facing deer management is critical to slowing the spread.
I’ll start this blog by stating the often-repeated facts about CWD- It was first discovered in a mule deer in Colorado in 1967, it is a prion disease, and it is always 100% fatal. Unfortunately, even that last claim is now being questioned. The new question being posed to state agencies is “how many deer have ever died of CWD.” However, this isn’t as easy of a question to answer as it seems. CWD takes time (typically at least 16 months) to incubate before the deer even show clinical signs, yet numerous controlled experiments have the same result- it eventually kills the deer. This poses several issues to biologists attempting to determine how many deer CWD has killed. First, it may come as a shock, but biologists don’t track individual animals waiting for them to keel over from a chronic disease. We develop estimates based on research, but coming up with an exact number is less important than determining the effects that the disease has on population trends. I’ll get to that in a second, but there is another big issue when researching CWD.
I’ve heard the claim, “CWD doesn’t kill deer,” described as a half-truth, which is the reason it has gained traction recently. CWD primarily impacts the brain of the animal, which can reduce their ability to avoid predation. In fact, animals infected with CWD are more likely to be hit by cars and killed by hunters, and often these animals are killed before they develop clinical signs that they are sick. Once the animal is clinical, their body condition is such that they are likely to develop other infections that eventually kills them, such as pneumonia. Regardless, in either case CWD results in the death of the animal. Consider a person suffering from Alzheimers or a similar disease that affects the brain who walks out of their home and wanders into the street and is struck by an automobile, what would we consider the cause of death to be? Certainly, the car played a role, but the disease that put the individual at risk and compromised their decision making is really at fault. CWD works in the same way, and people should stop acting like it doesn’t kill deer. They may not live long enough to ultimately die of CWD, but it still caused them to die sooner than should have.
Another popular claim these days is that CWD isn’t having population-level effects. This is partially due to the rapid spread of the disease, as it doesn’t cause population declines until it reaches a certain prevalence rate. However, studies in elk, mule deer, and whitetails all point to the fact that the disease can cause population declines once it has been around for long enough. It isn’t likely to ever cause extirpation of different populations, but lowered survival rates mean less hunting opportunity in the future. That is something to be worried about, especially with the declining hunter recruitment rates we now see!
Choose Your Information Sources Carefully
If I could leave you with one thought, it would be to pick your sources carefully. State and federal agencies that fund research on CWD rely on hunting license sales for revenue, so it would make absolutely no sense for them to make up a disease that IS going to negatively impact hunting! Biologists around the country that have devoted their life to the animals we love are being ignored while those making money by exploiting deer are getting a platform. Conspiracy theorists have a favorite saying- follow the money. I would urge you to do the same. Those who make their money on hunting license sales should want to promote hunting and the species that are hunted. Those who make money on deer farming want to promote deer farming, and CWD threatens their ability to do that. I’m not saying that they want to spread CWD, but a document or website funded by deer farming associations should probably be questioned. Nearly every celebrity hunter that is downplaying CWD has ties to this industry. So do your own research, but understand that those who have devoted their lives to the animals we love should be given more of a voice than celebrities on television.