It is our pleasure to reach the 20^th year of Pan Africa News (PAN), which was founded in the summer of 1994. We would like to express our sincere gratitude to everyone who has generously supported us as readers, contributors, and reviewers.

The late Professor Toshisada Nishida, the first Chief Editor, launched PAN in response to an idea generated at the conference “Understanding Chimpanzees”, which took place in Chicago, in November 1986. Dr. Jane Goodall and other chimpanzee experts felt that they needed a newsletter in which fieldworkers studying wild chimpanzees at various sites could share their information and experiences. At that time, the Gombe and Mahale projects had accumulated research experience spanning more than two decades, and many other projects exploring the two Pan species had emerged across Equatorial Africa. However, researchers were not always familiar with on-going studies and the conservation status of chimpanzees at sites other than their own. All they could get was relatively limited information through papers published in certain journals with wider readerships. PAN was intended to serve as a forum where fieldworkers interested in the Pan species could communicate informally to facilitate their research and conservation efforts.

For the past two decades, PAN has successfully lived up to expectations, but its role seems to have expanded. In 1997, we adopted a new editorial system for managing the submission and peer–review process to meet the needs of fieldworkers wanting to publish small findings about the Pan species, given that other scientific journals, even primatology journals, tend not to publish papers based on a single or rare observation. Subsequently, the diversity of wild chimpanzee behaviours in different areas became a hot topic, interesting many researchers. As a result, many good papers with invaluable findings, raising important issues, have appeared in PAN and, due to our open-access policy, have circulated within the scientific community and been cited frequently in other journals.

As we enter a new decade of PAN, we feel the need to change several of its elements so that we can maximize the niche that this journal has occupied. Such changes and improvements could include the guidelines for authors, editorial policy, publishing schedule, page layout, and journal title⁄description.

We might also widen the scope of this journal. Although we will keep our old policies regarding publishing information confined to chimpanzees and bonobos in the wild or in sanctuaries in Africa, it might benefit PAN readers if we publish papers on other species and news that is relevant to research and conservation of the Pan species. Next, we might start online publication on the day of acceptance, because the current biannual publication can keep early contributors waiting for 5–6 months until they see their accepted papers. Third, we should define policies for research ethics that we should observe while studying wildlife in Africa. We want to make such improvements in time for the next issue. Any suggestions will be appreciated.

We will post an update of each change online, once it has been fixed. Please visit our website (http:⁄⁄mahale. main.jp⁄PAN⁄) before you submit your manuscript.

Some editing changes have been applied to this issue. We have changed the citation style. We have abandoned the original style of superscript numerical citations in the text and adopted the more common style of the authorfs surname and publication year. References at the end of the paper should be listed alphabetically by the author's surname.

From the next issue forward, the deadline for manuscripts will be 1 month earlier; it has changed from the end of November to the end of October, which enables us to ask authors to correct their proofs. When you submit your manuscript, you can suggest two potential expert reviewers. You can also suggest researchers to whom we should avoid sending your manuscript for reasonable reasons. For further details, please see the online information.