, from http://web4.si.edu/sil/scientific-identity/display_results.cfm?alpha_sort=W

According to http://www.sil.si.edu/permissions/ :

Access to and use of digital image files, text, and data used on this web site are subject to the following terms and conditions. By using these materials, the user is deemed to have consented to the terms and conditions set forth below. For Smithsonian policy on this topic see: http://www.si.edu/copyright/

The digital image files and associated text on this web site are the property of the Smithsonian Institution or of other institutions or individuals.

The Smithsonian images are made available for non-commercial educational or personal use only.

And according to http://www.si.edu/copyright/ :

CONTENT IS PROTECTED BY INTELLECTUAL PROPERTY LAWS

Text and image files, audio and video clips, and other content on this website is the property of the Smithsonian Institution and may be protected by copyright and other restrictions as well. Copyrights and other proprietary rights in the content on this website may also be owned by individuals and entities other than, and in addition to, the Smithsonian Institution. Smithsonian expressly prohibits the copying of any protected materials on this website, except for the purposes of fair use as defined in the copyright law, and as described below.

Why PD?