In February 2017, 290 white-tailed deer biologists and other serious deer advocates congregated in St. Louis, Mo., where not 30 minutes from Daniel Boone’s home in Defiance they attended the 40th annual meeting of the Southeast Deer Study Group. The theme for this year’s meeting was disease. Science, politics, management and CWD took center stage.
According to Michael W. Miller with Colorado Parks and Wildlife and John R. Fischer of the Southeastern Cooperative Wildlife Disease Study, chronic wasting disease (CWD) has evolved from a minor curiosity to a national crisis since it surfaced in the late 1960s. As of November 2016, it has been reported in captive and/or wild herds in 24 states, three Canadian provinces, South Korea and Norway, and once established it continues to persist regardless of eradication attempts.
Although much has been learned about the biology and ecology of CWD, the authors stated that scientific information on effective management and control remains incomplete, rendering the eradication of it infeasible at present. They emphasized that CWD is here to stay, but must be continuously monitored in order to reduce if not eliminate its metastasizing capabilities, not only in the states where it presently occurs, but more importantly across state lines.
Nick Pinizzotto, President/CEO of the National Deer Alliance, stated that one of the organization’s top priorities focuses on deer diseases, particularly CWD. It has formed a working group that will provide information to the USDA concerning CWD program standards for management of captive cervids in addition to ensuring that the threat of CWD is better understood on Capitol Hill and amongst state legislators. One thing for sure, this biopolitical disease will remain under the microscope.
One of the principal concerns for the spread of CWD is the importation of cervid parts from known infested states. Merril Cook and Maria Palamar (North Carolina Wildlife Resources Commission) stressed the importance of developing and enforcing regulations that will reduce the risk of introducing the disease. They found only four of the 41 states they reviewed required reporting imported carcasses. Based on 326 North Carolina taxidermists who accept cervid carcasses and carcass parts, 45 percent believed their customers had minimal knowledge of the state’s carcass importation regulations, but 73 percent requested educational material.
As a result, North Carolina has initiated an outreach program to collaborate with other state agencies as well as North Carolina taxidermists to provide much needed information about regulations and the disease itself to hunters and processors. Their goal is to develop a model where various parties take interest in working together to reduce the risk of CWD spreading throughout the nation.
DEER IMPACT ON NATIVE HABITAT
The impact deer have on native habitat has always been a concern for deer managers and hunters alike. Graduate student Justin P. Young and his associates from the Caesar Kleberg Wildlife Research Institute and the Comanche Ranch in South Texas investigated the impact deer had on three different brush species in four 200-acre enclosures inhabited by 0, 20, 40 and 60 deer.
Each July and October, researchers collected leaf and stem samples from a different group of plants of each shrub species targeted, which included blackbrush acacia, twisted acacia and spiny hackberry, for nutritional quality analysis of fiber, protein and tannins. Based on preliminary findings, all three browse species exhibited compensatory growth and increased branching with up to 40 deer per 200 acres, or one deer per 5 acres, without developing any decline in nutritional quality or increases in thorns or tannin, which would inhibit their use by deer.
UNDERSTANDING DEER DEMOGRAPHICS
As in years past, Kip Adams and his associates at the Quality Deer Management Association delivered statewide harvest and management trends. Comparing antlered buck and antlerless harvests in 2015 to the previous five-year average for each state in the Midwest, Northeast and Southeast, shed some light on how the harvest has changed.
According to Adams, an overall decline in the buck harvest of 1 percent occurred in 2015 from the five-year average. The Midwest averaged a decline of 1.3, the Southwest 1.6, and the Northeast 2.2 bucks per square mile. More importantly, they found the average percentage of bucks harvested that were 1 1⁄2 and 3 1⁄2 years old or older was 34 percent and 35 percent, respectively.
The harvest of 3 1⁄2+ -year-old bucks was the highest recorded to date, indicating the desire of sportsmen to employ quality deer management strategies to improve their hunting experience. They also reported a 12 percent decrease in does harvested. According to Adams, age structure for bucks continues to increase and deer herds continue to be balanced, which reflect a bright future for deer hunters.
Although baited camera surveys are important for estimating deer populations, the time of year they are conducted can impact results. According to University of Georgia graduate student James T. Johnson, most surveys are conducted during late summer or early fall when sexual segregation is strongest and before buck groups separate.
In order to determine the effectiveness of preseason surveys when it comes to determining harvest, Johnson and his associates conducted a preseason baited survey employing one camera per 100 acres followed by passive camera surveys using one camera per 50 acres during the hunting season. They also did a post-season baited survey using one camera per 100 acres on three 2,500-acre camera grids in southwestern Georgia.
A total of 139,519 images were collected before, during and after the 2014-15 hunting season from both baited and passive cameras. Within the grids, preseason baited surveys had estimated densities of 47, 61 and 126 adult deer per square mile with 82, 75 and 214 unique bucks identified, respectively. Uniquely, 12 percent, 25 percent and 20 percent of the bucks identified during the preseason survey were not observed during the other surveys.
Also, unique bucks were identified during the passive and post season surveys that were not observed during the preseason. This indicated that preseason baited surveys might not be the most effective method of estimating the population available for harvest during the hunting season. This information also can be used by hunters as to when they conduct their scouting activities employing cameras.
ALL IN THE FAMILY
The genetic contribution of Northern lineages to free-range populations of white-tailed deer in South Central United States was investigated by Mississippi State University graduate student Jordan L. Youngmann and his associates from Mississippi State and Texas A&M University-Kingsville.
Youngmann investigated the long-term contribution of genetic stock from across the country, including Northern deer from Michigan, Wisconsin and New York translocated during the mid-1900s to boost declining populations in the Southeast. The author and his colleagues sampled free-ranging populations across Louisiana, Mississippi and Alabama at sites with a history of translocations of Northern deer using 15 microsatellite DNA markers. Southeast populations, according to Youngmann, were admixed and loosely divided east to west along the Mississippi River with further substructure apparent in populations receiving deer from North Carolina and native Alabama populations that were not stocked.
Based on their findings, only one area, the Black Warrior Wildlife Management Area in Alabama, revealed a relationship with deer from Iron Mountain, Michigan, which provided 105 (74 percent) translocated deer to that area. This was the only evidence of Northern lineages still present in Southeastern populations, which indicates that much consideration should be exercised when choosing stock sources for restoration efforts. It’s also my opinion that much scrutiny should be exercised in the captive cervid industry when it comes to attempting to augment genetic traits such as larger-racked bucks in Southern deer herds.
CULLING TO IMPROVE ANTLER QUALITY
Culling, or the removal of what sportsmen consider less than desirable antler traits, is a technique that is as popular as it is controversial. Texas A&M University-Kingsville graduate student Masahiro Ohnishi and his colleagues addressed culling effects based on a long-term study on the Comanche Ranch in South Texas. Three treatments, including intensive culling on 3,500 acres, moderate culling on 18,000 acres and a control area composed of 5,000 acres were reviewed.
Each fall, from 2006 through 2015, bucks were captured, age determined and antlers measured, and deer that didn’t meet culling criteria were sacrificed from 2006 to 2012. A total of 4,264 captures of 2,503 individual bucks were accomplished with 1,333 animals culled. Although most bucks were sired by males that exceeded the culling criteria, culling intensity of the yearling age class in the intensive treatment area ranged from 50 percent to 100 percent. Forty-eight percent of yearlings classified as culls transitioned from cull to accept- able at 2 1⁄2 years of age, while 33 percent would revert from acceptable to culls. Based on these findings, culling might not be as effective as most would like to believe for improving antler quality.
I am extremely impressed by the research conducted by the young researchers, who presented 16 of the 35 presentations, along with 18 exceptionally descriptive posters. It’s good to know that the future of white-tailed deer remains in good hands.
The Prestigious Career Achievement Award was presented at the annual banquet. The recipient was University of Georgia’s Karl Miller, who has inspired all with his knowledge, willingness to help students, and more importantly for his years of research conducted on white-tailed deer.