Gifford Garden Notes
Those d--- deer!
by Brad Roeller
Those d--- deer! As evidenced here at IES, coupled with the number of phone calls I've received seeking advise, the winter of 2002-2003 is going down as one of the worst I've witnessed as far as deer browsing is concerned. High deer populations, persistent and deep snow cover, and frigid temperatures frequently accompanied by strong winds, have pressured the deer herd to seek out seek out food that they would otherwise turn their respective noses at. Those of you who had the foresight to protect landscape plantings with physical barriers (boxing in plants with netting or burlap, or fencing of some type) are sure ahead of the game. Most all of the repellants that I've evaluated this winter have failed miserably. The lack of conducive weather conditions for reapplication of repellants has exasperated this situation. When was the last time we've had 40 deg. F. (i.e. the minimum temperature for spraying repellants) for any length of time? As most of you readers are aware, repellants must be applied at a 3-4 week interval to have any success in deterring deer from browsing. As of the writing of this edition of "Gifford Garden Notes", only one repellant, Plantskydd, has given me any degree of success. This product, a derivative of porcine blood, sprayed on selected plants in mid-November, has provided some protection on certain plants. Other popular products such as Deer Solution, Deer Off, Hinder, Bobbex, and Miller's Hot Sauce have all required second and third applications (which has been tricky given the persistent cold temperatures), and all have failed miserably in keeping deer from browsing on preferred landscape plants.
While I'm wringing my hands this winter over the fate of my favorite woody landscape plants, I remind myself that deer damage to landscapes is perhaps the least of our collective worries when it comes to assessing white-tailed deer impacts on other societal resources. These impacts can be categorized into the following areas: health-related, agricultural-related, deer vehicle incidents (anyone not had one of those?), impacts upon landscapes, and last, but certainly not least, the impact on our local forests by the current overabundance of deer.
Deer browsing on landscape and garden plantings affects approximately one-third of all residential households in New York State. Very conservative estimates of monetary losses due to deer browsing in New York run between $6.4 and $9.5 million per year. This equates to an average (conservative) of $475 per household spent on plant replacement due solely damage attributed to white-tailed deer. Nationally, the monetary impact of deer browsing in landscape plantings runs about $251 million annually.
While losses to landscapes is certainly not inconsequential (don't I know it!!), agricultural-related impacts attributed to white-tailed deer are similarly staggering. Deer cause more damage to crops than any other species of wildlife. Deer damage over 40 percent of our nation's crops, with conservative monetary estimates associated with this damage exceeding $100 million annually. Incidentally, some of the greatest damage occurs here in the good ole' northeast.
In recent years, public awareness of health-related problems with an overabundant deer population has grown considerably. We know that deer are an important vector for blacklegged tick-borne diseases including Lyme disease, human granulocyptic ehrlichioses, and human babesiosis. Incidences of Lyme disease have mushroomed 25 fold since 1982, with over 16,000 new cases reported annually. The public is just becoming aware of a couple of new, and potentially threatening, diseases that deer are susceptible to. Bovine tuberculosis, while rare in wildlife, has recently been reported in white-tailed deer. This bacterial disease affects the respiratory system of deer and has the potential to infect humans, livestock, and other wildlife. Chronic wasting disease, while rare east of the Mississippi, is of particular concern to wildlife biologists as well as sportsmen. It is unclear if this disease, similar to the headline-catching "Mad Cow Disease", can be spread to humans by the consumption of infected venison. Both bovine tuberculosis and chronic wasting disease are spread by nose-to-nose-contact, sneezing, and coughing. In light of this, the NYSDEC recommended proactive legislation, passed last fall, making it illegal to feed deer in NYS. Yes, deer do indeed pose a threat to human health.
At the writing of this week's "Gifford Garden Notes", my wife's SUV is in the body shop for repairs for what is technically termed a "deer-vehicle incident". Yes, I don't think there's a family in our area that hasn't had one of these. Here are some eye-opening stats: Nationally, there are over 700,000 deer-vehicle incidents reported each year. If we factor in unreported incidents, it is conservatively estimated that this number runs upwards of 1.5 million per year. Monetarily these incidents amount to over $1.1 billion (yes, that's a "b"!) per year, based on 1995 statistics. In that year, there were 29,000 reported injuries and 211 deaths attributed to deer-vehicle incidents. In NYS, there are well over 70,000 incidents reported each year.
Next week: The greatest (?) threat posed by white-tailed deer: impacts on our forests.
Gifford Garden Archives, January 2003 - present
Gifford Garden Archives, July 2001 - January 2003