Tracking the Disappearance of a Common Stream Frog: iNaturalist Data Leads to New Discoveries

_{Photo: ODFW biologists filter water samples using a portable pump in order to collect animal DNA from the local environment. Samples are then sent to a laboratory, and DNA material is identified to species. This approach ('eDNA survey") is an efficient way to detect sensitive aquatic species like foothill yellow-legged frogs without the stress to animals from handling. ODFW biologists are using frog data from the Oregon Wildlife Conservation Project to identify additional priority areas for eDNA frog surveys.}

Foothill yellow-legged frogs (Rana boylii) are an Oregon Conservation Strategy Species currently under review for listing under the U.S. Endangered Species Act (ESA).

Relative to habitat in central and southern California, Oregon is considered a stronghold for enduring populations of frogs. However, populations have declined significantly in the northern and southwestern portions of their Oregon range. In the absence of baseline data on population trends, biologists are uncertain of the extent and magnitude of decline in theses areas where frogs were once abundant.

To support conservation goals for foothill yellow-legged frogs, ODFW and federal partners are documenting frog abundance and distribution using eDNA surveys. This data will help biologists to map occupied habitat to better inform future management actions.

iNaturalist users can take part in this effort by adding foothill yellow-legged frog observations to the Oregon Wildlife Conservation Project. There are over 100 drainages in Oregon where no one has surveyed for foothill yellow-legged frogs despite availability of appropriate habitat, and user observations in these areas could expand the known range of the species.

Staff are also looking for frog observations in over 60 priority drainages in Oregon where there are no recent observation data to confirm if historically documented populations still occur. iNaturalist users have made some excellent frog re-discoveries in these areas, such as the observation below from project member @leppinm. The observation is the first time this species had been seen in the area in over 20 years.

The observation below, submitted by user @jermerckling in Curry County, is the first foothill yellow-legged frog seen in this historically occupied drainage since 1973. Additional surveys nearby in 1999 failed to detect the species, so this is truly an outstanding observation!

For poorly documented species like foothill yellow-legged frogs, the time and effort of community scientists provides critical data needed to support conservation decisions and actions. Thank you to the iNaturalist community for sharing your wildlife observations with our project to help ODFW protect and enhance wildlife populations in Oregon.

To learn more about how to add your observations to the project, see our user guide found here.

Posted on October 27, 2021 03:44 PM by oregonconservationstrategy