Download or read book Effects of SpayVac subscript TM on Urban White tailed Deer at Johnson Space Center written by Saul Hernandez and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: White-tailed deer (Odocoileus virginianus) populations in the United States have increased in recent years, particularly in urban and suburban landscapes where traditional measures of population control are difficult to implement. As a result of rapid urban development in the last several years, the Lyndon B. Johnson Space Center (JSC) located southeast of the Houston, Texas metroplex has become a refuge for an increasing, isolated urban white-tailed deer population. The use of the immuno contraceptive SpayVac[subscriptTM] has been proposed as a feasible measure in controlling the JSC deer population; however, the potential effects of the vaccine on deer movements are unknown. Furthermore, there is a need to estimate deer densities when using intensive management practices (e.g., contraceptive program) which requires an assessment of methods to estimate urban deer densities. The objectives of my study were to: (1) Compare female movements and ranges between deer treated with SpayVac[subscriptTM] versus non-treated (control) deer, (2) Determine if the timing of SpayVac[subscriptTM] treatment affected efficacy, and (3) Compare mark-resight and distance sampling methodologies in estimating urban deer densities. I captured and radio-marked 59 adult female deer at JSC. I found annual ranges between treated (mean 95% kernel = 82 ha, mean 50% kernel = 11 ha) and control (mean 95% kernel = 77 ha, mean 50% kernel =11 ha) deer were similar (P> 0.05). Furthermore, I found daily movements between treated (mean = 430 m) and control (mean = 403 m) deer also were similar (P> 0.05). The use of SpayVac[subscriptTM] did not alter movements and ranges of treated deer, and is unlikely to increase deer-vehicle collisions due to increased movements. I found the timing efficacy (i.e., time needed for vaccine to prevent pregnancy) of SpayVac[subscriptTM] was 0% for does treated closer to the breeding season than previously believed. For JSC, this expands the application time for SpayVac[subscriptTM] treatment to a 5-6 month window rather than the 2-3 month window as previously recommended. I found mark-resight estimates (160-174 deer) were congruent with minimum known alive estimates at JSC (158), whereas distance sampling estimates (83-114) were biased low. The use of non-random road counts likely resulted in the low estimates using distance sampling. I recommend that future efforts to monitor population densities at JSC use mark-resight estimates along with the on-going contraceptive program.

Download or read book White tailed Deer Population Dynamics and Management on the Lyndon B Johnson Space Center written by Shane Weston Whisenant and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 [trademark] 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 (>75 percent of female deer treated) were not effective in reducing population growth (R1). 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 [trademark] 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 ([approximately]25%) or a combination of sterilization and removal ([approximately]25%) to achieve the goals of JSC in maintaining current deer numbers. Removing or sterilizing50% of the female deer annually caused the JSC deer population to decrease to a level near eradication.