Acknowledgements
We thank members of the Moreau lab, Price lab and Jablonski lab for discussions, David Jablonski and Cathy Pfister for their comments on an earlier version of the MS, and Daniel Hooper for his original insights into the possible competitive effects of ants on birds. We would also like to thank Amir Chhetri, Suresh Brar, Suresh Rana, Deepika Karmarkar, Jobin Varughese, Vinod Shankar, Priyanka Das, Ritobroto Chanda, Pranav Balasubramanian, Sumit Bawalia and Abhijit Dey for assistance in the field. We are grateful to Amruta Varudkar, Prachi Thatte, Krishnapriya Tamma, Jyothi Nair, Anubhab Khan, Kevin Feldheim, Brian Wray and Stefan Green for help with lab work. Data collection was funded by a Young Explorer grant from National Geographic Society, a Rufford Small Grant and Henry Hinds Fund for Graduate Student Research in Evolutionary Biology to K. Supriya. K. Supriya was supported by a Field Museum Women in Science Fellowship at the time of data collection and a Faculty for the Future fellowship from the Schlumberger Foundation at the time of writing this manuscript. We would also like to thank two anonymous reviewers for their comments on a previous version of this manuscript.