We work hard to track news stories and research about deer management and Lyme disease issues. Time and time again, we see misleading information resurface. This particular article has some great points, but also perpetuates some of the misinformation that create decision-making inefficiencies when communities deal with deer management concerns and tick borne illnesses.
Here's the article: http://bit.ly/1q0SfTF. It might be good to read it or have it handy as you scan this post.
“Most deer culls don’t do anything to affect Lyme because they don’t get numbers low enough.”
This is sadly true. In looking at the overall effectiveness of culling and Lyme disease reduction, we agree with Allen Rutberg. It is difficult, with traditional recreational hunting strategies, to get deer densities low enough to break the tick life cycle and impact Lyme disease risk. However, with non-traditional strategies, like managed hunts and sharpshooting, that are very goal focused, we’ve seen the impact on Lyme disease first hand. On Monhegan Island, ME and Great Island, MA, all of the deer were removed, and Lyme disease became virtually non-existent. In Mumford Cove, CT, the deer population was dropped to 10 deer per square mile, and the number of Lyme cases dropped from a peak of 30 per year down to 2 or less. The correlation between deer density and tick abundance is consistently demonstrated time and time again when you exclude deer from areas larger than 5 acres. Overall, models point to a drop in Lyme disease cases at ~8-10 deer per square mile. It does take a lot of work to get to 8-10 deer per square mile, and of course, ongoing work to keep it there. Rutberg is right. It isn’t fun and it is hard work, but it can be done. Culling is a proven tactic to combat Lyme disease when used strategically. Given the Lyme disease problem, and the strong correlation between deer and tick abundance, we will continue to pursue a variety of strategies to help curb deer densities in areas with Lyme disease risk.
“Fertility control will be an ineffective way to control Lyme.”
It depends. In our mind, the jury is still out on fertility control, but we want to continue the research. There are two fertility control methods available, immuno-contraceptives and surgical sterilization. At this point, after a great deal of vaccine research, we’ve moved to mostly surgical sterilization. The vaccines simply aren’t as effective as the surgery. When we conduct surgery, we only need to handle the animal once. The challenge with contraceptives like PZP and GonaCon is that they require subsequent revaccination, not all animals respond to the vaccine, and each animal will need to be handled multiple times. We’ve looked at the vaccine technology, been hopeful, but ultimately have turned to surgical sterilization as an alternative.
The cost of fertility control is typically more than culling. There are a variety of additional needs in a fertility control program. While there is no immediate reduction in herd size, at least the effects are permanent. We continue to look for ways to reduce the cost of this method and pair it with other methods to improve reduction timelines. We agree, 10 deer per square mile is a difficult achievement, unless the effort is organized, ongoing and measured. Given the concerns voiced by the public, we believe we need to forge ahead with this approach. We are hopeful, but are still in the research stage, that if we limit reproductive output, we will see subsequent declines in population. If a community needs a faster outcome, we can pair sterilization with managed hunts. There are a variety of considerations to determine the best method, ranging from budget to desired outcome.
“Block Island considered spending $500,000 last year to hire a sharpshooter.”
Misleading. As an aside, to make sure folks know we aren’t getting rich from wildlife work, Block Island was budgeted to spend about $90k in 2014 for White Buffalo’s support. There was no long-term contract and the costs would have dropped precipitously in future years, as the bulk of the work would have been completed in Year 1. We are not exactly sure where the $500k figure came from, but our fees go to support direct expenses, labor, and if there is profit, it gets reinvested into research and education on management tools, techniques and Lyme disease. We aren’t just sharpshooters, but sharpshooting is one of a variety of methods we use to achieve a community’s goals. We are biologists, veterinarians and ecologists. We are working on a variety of research projects, including surgical sterilization, humane darting techniques, and protocols to improve humaneness of field euthanasia in wildlife.
“Deer population will rebound after a cull due to compensatory reproduction.”
Misleading. The notion of a “rebound” or “population explosion” is not accurate. There won’t really be more incidents of twins or triplets. There may be a slight increase in survivorship of fawns, but it would only be noticeable in situations where the deer were in poor physical condition prior to management efforts. Of course, there will be new fawns each year. Reproduction doesn’t stop. In order to maintain the population at desired levels, there will need to be continued management (culling or sterilization). Triplets are infrequent and most healthy adult females already have twins. We always wonder exactly what an explosion would look like in areas where the deer are already healthy. So, the population will grow in subsequent years, but there really isn’t a dramatic “rebound” or “explosion.”
“The Centers for Disease Control and Prevention and national health authorities do not recommend deer hunting to control Lyme disease.”
““It’s a whole different host ecology,” “To compare Monhegan Island to Jamestown would be “like apples and bananas.””
Misleading. We don’t think Monhegan Island is all that different from Jamestown, RI. We did the work on Monhegan, and it was difficult. As Wildlife Ecologists using sharpshooting as a management tool, we eliminated deer from Monhegan in the 1990s, and Lyme disease disappeared. While Jamestown is closer to the mainland and deer do swim, it is unlikely that the island would rapidly be repopulated. Deer may never be completely removed, but you could keep the population down to recommended levels with ongoing management. Obviously, the host ecology on Monhegan initially worked to support Lyme disease without a population of mice. Monhegan had rats that acted as a surrogate for mice in supporting the disease cycle. Not sure how the host ecology matters in this instance. Lyme disease existed in both cases.
“People discuss Lyme disease as if it’s a huge problem, but then are not willing to spend any money.”
True. We do agree that addressing Lyme disease and other tick borne illnesses will cost communities money, and there isn’t enough being done. Lyme is the most commonly reported vector-borne disease in the US. It is our version of Malaria and we must figure out how to combat it. If you think about it, Florida alone spends about $160M annually for mosquito control, and communities should not be surprised that managing for this illness becomes a line item in their budget.
As always, feel free to email us at email@example.com. We are striving to put forth the best available science to help drive considered change for humans and wildlife.