White-tailed deer population dynamics and management on the Lyndon B. Johnson Space Center

Abstract

White-tailed deer (Odocoileus virginianus) numbers on the National Aeronautics and Space Administration's (NASA) Johnson Space Center (JSC) in Houston, Texas have increased in recent years and are a cause of urban-related accidents (e.g., deer-vehicle collisions, negative interation with humans). Safety personnel for the JSC are interested in reducing human-deer interaction by a reduction in overall population numbers. My overall study objectives were to (1) estimate population parameters for JSC deer, (2) develop a computer simulation model for the JSC deer, and (3) evaluate 2 management strategies to control JSC deer numbers a priori using the JSC deer model. The 2 management strategies I evaluated were the efficacy of SpayVac immunocontraceptive vaccine (sterilization) and trap and translocation (deer removal) efforts in managing white-tailed deer on JSC. In general, single treatments of removals or sterilization (less than 75 percent of female deer treated) were not effective in reducing population growth (R greater than 1). Approximately 50% of female deer needed to be removed annually to reduce population growth whereas approximately 25% of female deer needed to be treated annually with SpayVac for the same effects. A combination of trap and removals and sterilizations was effective in reducing population growth when applied to approximately 25% of the female population annually. I recommend the use of sterilization annually (25%) or a combination of sterilization and removal (25%) to achieve the goals of JSC in maintaining current deer numbers. Removing or sterilizing > 50% of the female deer annually caused the JSC deer population to decrease to a level near eradication.