This article reports the results of a study with 70 senior undergraduate biological science majors enrolled in a required course on "Writing and Speaking in the Biological Sciences". Students enrolled in this course were expected to develop oral scientific presentations of their research projects that exemplified the norms of speaking in the biological sciences. Rather than gathering information from experts or providing explicit instruction on the conventions and structure of this particular genre, we surveyed the students enrolled in this class about their self-perceived communication challenges. Students overwhelmingly identified general issues of organization and concerns about delivery as their primary challenges and communication workshops were developed to address these concerns. According to the reports of the biology faculty who evaluated these students' presentations and grade data for the oral component of this course compared to previous sections of it, students demonstrated significant expertise in enacting a highly discipline-specific oral communication task. We attribute these students' ability to successfully deploy such discipline-specific discourse to their own tacit knowledge of their field combined with instruction in both the disciplines of rhetoric and biology.