Date of Award


Degree Name

Master of Science


Biological Sciences

First Advisor

Dr. Stephen Malcolm

Second Advisor

Dr. David Cowan

Third Advisor

Dr. David Karowe

Access Setting

Masters Thesis-Campus Only


Very little research has been performed on the effects of Bacillus thuringiensis maize (zea mays) on wild mammalian herbivores, yet its use has been increasing since 2000. Because of this, I examined the effects of Bt maize on white-tailed deer herbivory. This was accomplished through a field experiment in which one block consisting of Bt and non-5/ maize was planted, with half of the plants fenced during the vegetative growth phase, at nine different locations in southwest Michigan. During the vegetative growth phase, deer did not discriminate between Bt and non-5/ maize (on average, 16% and 20% experienced herbivory, respectively). After maturity, Bt and non-5/ maize did not differ in weight, but non-5/ maize was taller. Tassels from both varieties had approximately the same height and weight. Number of fruit consumed did not differ between the two varieties. Differences in fruit weight, however, were significant. Fenced plants were taller than non-fenced plants, but had equal number of fruit per plant. Overall, I found that deer do not discriminate between Bt and non-5/ maize. Additionally, non-5/ maize may have a higher growth rate, but the same crop yield, as Bt maize. Lastly, data indicate that white-tailed deer decrease plant growth.