In this study, undergraduate science instructors and faculty were surveyed and interviewed to investigate the information literacy needs specific to their disciplines. Respondents shared their perspectives on IL skill development throughout science degrees and the dependence of that skill development on successful study within the field. Analysis of the results expands on current understanding of the types of resources most useful to early degree students, the most appropriate IL skills to prioritize as students progress through their degrees, and the challenges that reading and critiquing primary research pose for students. Findings from the study align with previous research on information use and literacy in the sciences and build on it by offering librarians greater insight into what underlies, drives, and impedes IL skill development for science students. Practice recommendations based on study findings are made for librarians teaching science students.