Special Snowy Plover Mud Stomp

By SFBBO Science Director Maddy Schwarz

On March 8 we hosted a very special Snowy Plover Mud Stomp volunteer day at Eden Landing Ecological Reserve in Hayward to install cutting edge Motus technology.

Motus tags are a type of radio transmitter that send signals to nearby radio antennas. A single Motus station was established at Eden Landing in November 2021 which receives data from any tags on birds and other wildlife and some insects it picks up within 30 kilometers.

However, because it's only one antenna, it's impossible to triangulate the exact location of the tags it registers. 

Because we wanted more than just presence/absence data and to get fine-scale movement data, at the Mud Stomp we established a grid of “nodes,” which are essentially miniature receivers that will collect data from the tags and transmit it to the full-size ​antenna. The nodes will transmit their data to the main Motus station, which will in turn post the data online, allowing us to view where tagged birds are in real time. 

At the Mud Stomp, seven volunteers and partners from H.T. Harvey and Associates and Avocet Research Associates helped our staff set up 56 nodes, using rebar and conduit sheath, on posts situated along a grid that covers the entire areas of Ponds E14 and E6B.

The next step is to finish the retrofit of the Motus tower south of Pond E14 by adding the omnidirectional antenna. Then, we'll hopefully begin tagging plovers in June! 

This is part of our first ever U.S. Western Snowy Plover Motus tagging study, which we are undertaking this year. Although this is only a small exploratory study, we are hoping to learn more about where plovers go at night, where the most popular places for broods to spend time on the ponds are, and how soon a female starts a new nest once the current one is no longer active. 

​You can read more about this technology on the Motus Wildlife Tracking System website. (photos below by Joe Montes)