Frequently Asked Questions about the CNDDB


What is the difference between the CNDDB, RareFind, and BIOS?

The California Natural Diversity Database (CNDDB) is a database that records information about California’s most imperiled plants, animals, and natural communities.

RareFind is a web application that allows you to query and run reports on the text information in the CNDDB.

The Biogeographic Information and Observation System (BIOS) is a web map viewer that can be used to view thousands of biogeographical datasets. CNDDB data make up a few of those datasets in BIOS and may be viewed spatially through the BIOS map viewer.

What is an element?

The CNDDB uses the term "element" to define what we track in our database. Elements are often species, but depending on the situation, an element may also take the form of a subspecies, a plant variety, an animal evolutionarily significant unit (ESU), a distinct population segment (DPS), an aquatic community, or a terrestrial community. The CNDDB manages data for imperiled elements and maps occurrences for many of those elements.

What is an element occurrence (EO)?

An element occurrence is a summary of the textual and spatial information the CNDDB knows about an element in an area. The text portion of the occurrence is viewable through RareFind. Occurrences are represented spatially as polygons on a map, viewable with the BIOS map viewer or GIS software. As the CNDDB receives more information, element occurrences may change in size and shape over time, and the text portion of the occurrence will summarize more years of information.

Submitting Data

Who does the CNDDB accept data from?

Anyone can submit data to the CNDDB. You do not have to be a professional scientist to submit data to us. Most of the data submitted to the CNDDB comes from researchers, agency biologists, biological consultants, and non-profit organizations. CNDDB staff follow up on questionable submissions if submitted data appears out of range for a particular element, is detected during the wrong time of the year, or could have been mistaken for a similar species that occurs in the same area.

The CNDDB does not map all detections (such as bird flyovers). Should I bother submitting data if the CNDDB does not plan to map it into occurrences?

Yes; please send in all your data. We would rather have too much data than not enough. Some data may not warrant being mapped as element occurrences on their own but can still be useful as supporting information when put in context with other data. If you submit your positive or negative data through our Online Field Survey Form web application, the information will be available for CNDDB subscribers to view in BIOS the following month.

The Online Field Survey Form only allows you to input data for one observation/species at a time. Is there a way to submit information for multiple species at the same time, or bulk upload it?

There is not currently a way to bulk upload data, but we are always working towards making it easier for people to submit data to us. In the meantime, we accept data in multiple formats, and if you email us with details about the format your data is in, we can work with you to determine the best way to submit your data. More information is available on our Submitting Data page.

Tools and Products

What is a 9-quad search?

Can you run a 9-quad search using RareFind?

9-quad searches should only be done using the CNDDB QuickView Tool and should not be done in RareFind. RareFind only reflects data that has been mapped into the CNDDB as element occurrences, whereas the CNDDB QuickView Tool displays data that has been processed and mapped as element occurrences as well as data that is unprocessed and waiting to be mapped. In addition, the CNDDB QuickView Tool incorporates data from the Spotted Owl Observations Database, which RareFind does not.

Using CNDDB Data

How do I access CNDDB data?

CNDDB data may be viewed spatially with the BIOS map viewer, or as text and reports through RareFind. The two web applications are connected; you may select occurrences in BIOS and pass that selection into RareFind to look at the specific text information associated with those occurrences, or query for occurrences in RareFind and pass the results into BIOS to view those occurrences spatially.

For those with access to GIS software, CNDDB and Spotted Owl Observations Database spatial data are available for downloading. More information is located on our Monthly CNDDB Data Download page.

How do I get information for suppressed records?

Please email us your justification for requesting suppressed data. If you have a project in a quad with a suppressed element, please email us the location of your project, and we will provide you with more information on the suppressed records near your project.

How do I get the point data for CNDDB occurrences?

The CNDDB used to distribute both point and polygon data files but the point data was frequently misused; we currently only distribute polygon data. Users with GIS capabilities can convert the CNDDB polygon spatial data into point data if needed. Please contact the CNDDB program for additional information on the proper use of point data and for instructions on how to do this.

Is there observation data available for CNDDB occurrences?

While CNDDB observation data is not available at this time, the Biogeographic Data Branch (BDB) manages and hosts a number of observation datasets. These include the Unprocessed Data from the CNDDB Online Field Survey Form web app and the Spotted Owl Observations dataset which are available to CNDDB subscribers in the BIOS Viewer. Our spotted owl data is located solely in the Spotted Owl Observations Database.


Why is the CNDDB a subscription database when I can find rare species locations on GBIF, iNaturalist, etc. for free?

The legislation which founded the CNDDB program requires that users share a portion of the costs of maintaining the CNDDB. The money gathered by CNDDB subscriptions helps us fund the most comprehensive database of California's imperiled species. The CNDDB includes data from diverse sources, some of which are already in the public domain, but much of our data is submitted directly to the CNDDB and not readily available anywhere else.

Is there a way to view CNDDB data without being a subscriber?

You may view CNDDB data in a generalized manner using the CNDDB QuickView Tool. The CNDDB QuickView Tool is a free tool in the BIOS map viewer that will generate a list of species for which the CNDDB has mapped data and/or unprocessed data in specified quads or counties. You can also search by species.

What is the difference between the Commercial and Government versions of the CNDDB data?

The Commercial and Government versions of the CNDDB data are generally the same, but 1% of the data is suppressed for the Commercial version. This 1% represent the most rare and imperiled elements or occurrences. Please contact the CNDDB program if you need more information on a suppressed record.

Training and Updates

How do I learn more about using the CNDDB?

You may learn about the CNDDB and our tools and products through the Biogeographic Data Branch's Training page. There, you can find training videos, user guides, and the schedule for upcoming training sessions.

How can I stay updated on changes in the CNDDB?

Any major changes to the CNDDB will be conveyed to our subscribers through email and posted on the CNDDB News Blog.

CNDDB Feedback

How can incorrect records be fixed or removed from the CNDDB?

The CNDDB program strives to make our data as accurate and complete as possible. Please send us an email describing which occurrence(s) you believe are in error and provide us with any documentation you may have.

Why does the CNDDB appear to have gaps in information? There are some populations I know of that are not mapped.

The CNDDB works hard to maintain a high-quality database of imperiled elements in California with the staff and resources available to us. If you see data gaps, please reach out to us. We may have not received the data, or the data could be in our files waiting to be processed. If you want to submit data, please refer to our Submitting Data page to see the various ways data can be submitted to us.

Why does it appear that Community occurrences in the CNDDB are outdated?

The CNDDB is not currently updating Natural Community occurrences, but the legacy information is still available. For more up-to-date community information, please see the Vegetation Classification and Mapping Program (VegCAMP) page.

If you have a question that is not answered on this page, please send us an email and we will be in touch.