Twitter is a cold medium that allows users to deliver content-rich but small packets of information to other users, and provides an opportunity for active and collaborative communication. In an education setting, this social media tool has potential to increase active learning opportunities, and increase student engagement with course content. The effects of Twitter on learning dynamics was tested in a field biology course offered by a large Canadian University: 29 students agreed to take part in the Twitter project and quantitative and qualitative data were collected, including survey data from 18 students. Students published 200% more public Tweets than what was required, and interacted frequently with the instructor and teaching assistant, their peers, and users external to the course. Almost 80% of students stated that Twitter increased opportunities for among-group communication, and 94% of students felt this kind of collaborative communication was beneficial to their learning. Although students did not think they would use Twitter after the course was over, 77% of the students still felt it was a good learning tool, and 67% of students felt Twitter had a positive impact on how they engaged with course content. These results suggest social media tools such as Twitter can help achieve active and collaborative learning in higher education.