Tidal Mudflats: More than Meets the Eye

Connecting the dots between our beloved shorebirds and the habitats important to their survival is essential to Audubon’s mission to  protect birds and the places they need. By exploring this relationship more closely, we learn which habitats we should conserve for our feathered friends — including tidal mudflats.

Understanding Tidal Mudflats

Mudflats: not the most charismatic word to describe a location out on the beach. But to shorebirds and seabirds alike, it’s where they find sanctuary. Whether it be a roosting site for seabirds seeking a worthy place to rest their wings or an all-you-can-eat buffet for shorebirds in search of nutritious fuel to keep them going, tidal mudflats are the answer.

Intertidal mudflats consist primarily of a mixture of clay and silt brought in by the sea deposited into bays through tidal movement. If you’ve ever had the opportunity to step foot on a mudflat, you may have noticed that the sand is mucky and saturated, almost resembling quicksand.

Foraging Grounds

When exploring a mud flat, you may notice tracks made by hungry birds going every which way, tracing their search for food. Evidence of life under the mud is obvious as the flats are filled with porous holes made by intertidal organisms like crustaceans, marine worms, mud snails, and clams. As the tide falls, revealing the sand below, vulnerable marine life becomes exposed and inevitably falls victim to the metabolic needs of eager shorebirds. Luckily for some, the tide will certainly rise again, and the shorebird-feast-survivors live to see another high tide.

Refueling Stations during Migration

Mudflats serve as “rest stops” for the millions of shorebirds that migrate across the hemispheres every spring and fall. Migratory shorebirds face a constant arsenal of life-threatening challenges throughout their journey, but the timing of migration is closely tied to food availability, making productive mudflats the essential links to a much larger migratory shorebird network. Stopover sites allow the many different species of shorebirds to replenish energy and fat reserves needed to complete the next leg of their demanding journey. Access to healthy mudflats as they travel across the hemisphere can be the difference between life and death, affecting overall species survival and future shorebird population trends.

Nursery and Breeding Support

During the summer months, when shorebirds are busy raising babies, mudflats function as training grounds for chicks learning how to forage. The abundance of resources that the flats provide makes prey accessible for parents and their young, increasing the odds of juvenile survival and supporting the most vulnerable stage of life. Recently fledged seabirds like Least Terns and Black Skimmers will also seek refuge along the exposed flats as they prepare for the difficult migratory journey ahead.

Protecting the Places Shorebirds Need

Tidal mudflats may appear unassuming at first, but beneath the surface lies a dynamic ecosystem that fuels migration, supports growing families, and sustains shorebirds throughout every stage of their annual cycle. Our team works throughout the year to monitor which sea and shorebirds use tidal mudflats in our stewarding areas so we can better protect them now and into the future. Audubon is raising our sights, and our impact, across the full length and breadth of our hemisphere — both the migratory pathways of today and the refuges birds will continue to seek out (like tidal mudflats) as climate change progresses.

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