It is our great pleasure to present the Proceedings of the 26th International Ornithological Congress (IOC), which was held at Rikkyo University in Tokyo from 18 to 24 August 2014.

The International Ornithological Congress has a strong tradition of bringing together the latest and best research on birds, with a mixture of review papers presenting an overview of their fields, and topical contributions on recent findings. The 26th IOC has continued this tradition and provided not only a highly enjoyable but also a scientifically rewarding environment, where researchers have been able to meet, share ideas and insights, and strengthen collaborations in the global science that ornithology has always been. It was the second ever IOC to be held in Asia, the 2002 Beijing conference being the first. The Congress had over one thousand attendants with 907 presentations (including 518 posters), as well as 15 round table meetings and several working group meetings.

These Proceedings are published online as a supplement to the Journal of Ornithology. They include papers by plenary speakers and invited keynote presentations in the Symposia. These papers span all of the fields in which ornithological research is conducted and give a representative view of the current state of ornithology.

We would like to sincerely thank the contributions of all authors and reviewers, and the support from the editorial staff at Springer.

Erik Matthysen—Chair of the Scientific Program Committee*

Keisuke Ueda—Secretary General of the 26th IOC*

Franz Bairlein—President of the 26th IOC

*Invited Guest-Editors of the Journal of Ornithology