Rails, Camera, Action!
February 29, 2024
The tidal marsh field season is happening as you read this! Tidal marshes are a type of wetland that is found along salty bodies of water, are composed of plants and organisms that are specifically adapted to salty environments, and that provide many benefits to wildlife and people. For the 28th year, Point Blue biologists have their rubber boots out in the soggy, squishy, salty, pickleweed-covered mud monitoring sensitive bird species like the federally endangered Ridgway’s Rails. Last year, we began a new pilot study to investigate how extreme high tides are really affecting these secretive marsh birds.
We’re putting cameras out during the winter high tides to spy on the rails without disturbing them. On the highest of tides, the water covers much of the pickleweed and other low-growing marsh plants that the rails can take cover under–which makes it a lot harder for them to hide from predators. We are capturing and analyzing the interaction of tides, predators, and plant cover, and we’re already seeing a significant result: the denser the vegetation in the marsh, the safer the rails are from predators during high tide and storm events.
This may seem obvious, but it matters when we think about science-driven conservation action. Information like this informs how our programs like STRAW (Students and Teachers Restoring A Watershed) and other restoration efforts by agencies around the San Francisco Bay design their habitat restorations in and around tidal salt marshes.
Climate change is increasing the frequency and severity of the storms, and rising sea levels. While sea level rise is a slow but steady threat, storm events are very real and tangible, and are happening right now. From our data we’ve seen that rail populations seem to have swings in population numbers from year to year. So, one ill-timed storm event in a low population season could be disastrous for this species. Our last population count estimate, as of 2021, was around 1,400 individual Ridgway’s Rails. We’re aiming for a steady population number closer to 5,400. So, we’ve still got a lot of work to do. When rail plant cover options are only 30-50 cm tall in their tidal marsh home, a relative sea level rise rate of almost 2 mm per year makes a big difference! That’s why it’s critical for conservationists, policy makers, and the public to do all they can now to support this species’ survival.
And why should you care about tidal marshes and rails? Because we are connected in the same ecosystem web. Tidal marshes also provide critical benefits to human populations. They soak up carbon out of the atmosphere, filter pollutants out of the water, produce oxygen, and provide sheltered nurseries for fish and crabs that fuel the seafood industry. Because the rails’ survival is so tied to the health and availability of the tidal marsh, the status of their populations tells us about the health of tidal marshes across the San Francisco Bay. To summarize, healthy rail populations equal healthy SF Bay human populations!
So, what can the average San Francisco Bay Area resident do? Remember our mention of predators? Those include domesticated animals and common wild animals that we can unknowingly be supporting. Keeping cats indoors, dogs on leashes, and trash covered makes a huge difference to reduce stress and pressure on this already stressed species. Those simple actions along with supporting policy and organizations that restore and protect tidal marsh will really move the needle towards a stable future for rails and the rest of our communities.
Want to learn more and get involved? Send us questions via info@pointblue.org. Donate to Point Blue to support our long-term tidal marsh research via www.pointblue.org/donate. And stay tuned for our art and science collaboration on tidal marsh species with Observation Society!