Introduction and Background

The Biodiversity Heritage Library (BHL) is the world’s largest open access digital library for biodiversity literature and archives.

Natural history books and archives contain information that is critical to studying biodiversity but much of this material is available in only a handful of libraries globally. Scientists have long considered this lack of access to biodiversity literature as a major impediment to the efficiency of scientific research. BHL operates as a worldwide consortium of natural history, botanical, research, and national libraries working together to address this challenge by digitizing the natural history literature held in their collections and making it freely available for open access as part of a global “biodiversity community.”  Harvard's Ernst Mayr Library and Botany Libraries are founding members of the global consortium. 

BHL provides free access to hundreds of thousands of volumes, comprising over 60 million pages, from the 15th-21st centuries. In addition to public domain content, BHL works with rights holders to obtain permission to make in-copyright materials openly available under Creative Commons licenses.  Because of its historical nature, the collection includes some materials that do not reflect the current values of the BHL. For more information, see the BHL Acknowledgment of Harmful Content.

The BHL consortium works with the international taxonomic community, publishers, bioinformaticians, and information technology professionals to develop tools and services to facilitate greater access, interoperability, and reuse of content and data. BHL provides a range of services, data exports, and APIs  (Application Program Interfaces) to allow users to download content, harvest source data files, and reuse materials for research purposes. Through the Global Names Recognition and Discovery (GNRD) service, BHL indexes the taxonomic names throughout the collection, allowing researchers to locate publications about specific taxa. The tools and services from BHL improve research methodology and save time and money for those needing biodiversity literature.  More details are available on the Biodiversity Heritage Library About page.

Examples of types of searches for BHL:

  1. Searching for original species descriptions
  2. Gaining historical perspective on an organism, person or place via original field notes or publications
  3. Obtaining high-quality freely accessible scans of 18th and 19th century works with complete illustrations (sometimes oversized)
  4. Finding publications not represented by large publishers and commercial websites, such as museum and nature society journals.

After reviewing this guide, readers should be able to:

  1. Perform basic searches in BHL
  2. Know the difference between full-text and catalog search
  3. Perform advanced searches
  4. Download PDFs
  5. Download images from the BHL website and also from the BHL Flickr site.

Acknowledgements:  This guide was originally written by Constance Rinaldo, Librarian of the Ernst Mayr Library of the MCZ from 1999-2021.  Continuing thanks to Barbara Ferry,  Polly Lasker, and Angel Aguirre of the Smithsonian Libraries for sharing their work and to Diane Rielinger at the Harvard University Botany Libraries and Mary Sears, Head of Public Services in the Harvard University Ernst Mayr Library for their contributions.