The two-year deer telemetry study spearheaded by the Louisiana Department of Wildlife and Fisheries (LDWF) and the Louisiana State University’s (LSU) School of Natural Resources was completed in early April.
LSU grad student Justin Thayer’s thesis entitled “Population Characteristics of a White-tailed Deer Herd in a Bottomland Hardwood Forest of South-central Louisiana” is now available at http://etd.lsu.edu/docs/available/etd-04142009-092649/.
The primary objectives of the study were to assess range and movements, evaluate age and sex-specific harvest rates and evaluate survival and causes of death among white-tailed deer in a Louisiana bottomland hardwood forest under a quality deer management plan.
A total of 65 deer were captured in West Baton Rouge and Iberville parishes during 2007 and 2008. The research team radio-marked 37 males and 11 females and earmarked an additional 10 males and seven females.
The study found that home ranges for adult males during the spring were 380 acres, during the summer were 174 acres and during the fall were 291 acres. Female home ranges were 166 acres during the spring, 133 acres during the summer and 62 acres during the fall. Juvenile (1.5 year-old) males increased space use 169 percent in the spring (572 acres) relative to the summer (213 acres) and maintained 50 percent larger home ranges than adults during the spring.
The study group observed smaller home ranges than anticipated or seen previously, suggesting that landowners managing smaller tracts of property may be able to practice quality deer management at scales thought to be ineffective at improving herd dynamics.
Survival estimates for adult males was 100 percent during the spring, 95 percent during the summer and 55 percent during the fall. Mean annual survival for adult males was 53 percent. No mortalities were observed in spring or summer for juvenile males, but ear-tag returns and harvest records indicated juvenile males were being harvested at a rate approaching 20 percent.
The mean annual mortality rates from harvest were 40 percent and non-harvest sources of mortality were 16 percent. Non-hunting mortality included both natural causes (8 percent) and deer-vehicle-collisions (8 percent).
According to the thesis, due to low non-hunting mortality, young males (less than 2.5 years) are likely to survive to the next age class if protected from harvest, but ultimately have a small chance of reaching maturity (5.5 plus years) because males are generally harvested as they approach the antler restriction in place. Managers should seek to increase fall survival for males, if management objectives include increasing the frequency of harvesting males over 3.5 years old.
The study was conducted on approximately 40,000 acres of bottomland hardwood forest located west of Baton Rouge and east of the Atchafalaya Basin. The study area was leased to more than 30 private hunting clubs, and each club belonged to a cooperative that promotes quality deer management on the property. A. Wilbert’s Sons L.L.C. is the primary landowner and cooperator and also provided technical, logistical and housing support for the researchers.
White-tailed deer are an important economic and recreational resource across their entire range. In Louisiana and other southeastern states, land managers are choosing strategies geared toward developing quality deer herds. Because this management regime involves restricting harvest of younger-age-class bucks and increasing the harvest of females to lower herd density, substantial interest exists in understanding the effects of quality deer management on population characteristics.