Winter/Spring 2001

Current Research: Quantifying Physical Characteristics of Mississippi's Deer Herd

Dr. Steve DeMaris and his students of the Forest and Wildlife Research Center at Mississippi State University are researching the physical characteristics of the Magnolia State's deer herd.

They analyzed the data from the Deer Management Assistance Program (DMAP) to determine if age-related antler and body mass development differs among the physiographic regions (Loess Bluffs, Delta, Coastal Plain, etc.) of Mississippi. If differences in antler development existed, they wanted to determine if a statewide harvest regulation (e.g., 4-point rule) could impact the composition of regional buck harvests. They calculated the proportion of young bucks protected for each physiographic region using various antler selection criteria to determine if discrepancies existed in protection rates. Additionally, they wanted to determine the effects the 4-point regulation had on age structure and average antler size of harvested bucks in Mississippi. To further an understanding of how selection criteria affect these parameters, they developed a simulation model using penned deer antler records to assess the efficacy of numerous selection criteria on the average antler score of the buck harvest through manipulation of the harvest age composition. Further, they developed a simulation model to determine if cohort (i.e., group of individuals born in the same time period) antler size can be degraded in subsequent years with selection criteria that protect smaller-antlered young bucks and permit the harvest of larger-antlered young bucks. They also analyzed Wildlife Management Area (WMA) harvest data to determine if cohort antler size had indeed changed since implementation of the 4-point rule.

DeMaris and his researchers revealed that antler and body size and the rate of growth differed by region. Therefore, they concluded that soil fertility affects the potential for antler and body mass size as well as the rate at which animals reach these potential values. Due to regional differences in antler development, the proportion of young bucks protected with the 4-point rule (and other selection criteria) differs across Mississippi.

Their modeling efforts confirmed that the average antler size of the buck harvest can be increased using selection criteria which alter the age composition of harvest by protecting yearling bucks. However, their models also revealed that these same selection criteria can degrade antler quality of the cohort in subsequent years. Analysis of harvest records from Mississippi WMAs corroborated these findings. They found that the 4-point rule had changed the age composition of the harvest and therefore changed the average antler size of the harvest. Further, there is evidence of cohort antler degradation on a WMA due to selectively removing the larger-antlered yearling bucks with the 4-point rule.