Exploring the Riverwalk’s invisible wetlands

Photo courtesy Barry Knott
A Virginia rail in the Riverwalk wetland reeds.

By Josh Pike
Pagosa Wetland Partners

The Pagosa Riverwalk wetlands provide a bounty of easily observed natural attractions, from the gently flowing channels and ponds filled with water birds and insects to the banks of reeds and cattails topped with songbirds and flowers. 

Many of the processes that make this area so fascinating and biologically rich are far less visible, hidden in the dense vegetation which grows in the mineral rich waters. In these thickets, birds make their nests and raise chicks, amphibians hibernate during the winter and find shelter in the summer, and insects lay eggs and feed. These activities form an “invisible wetland”: a group of organisms and interactions largely outside the perception of a casual human visitor, but critical to creating the rich and biodiverse area we enjoy as we walk the Riverwalk trail.

The foundation of the invisible wetlands are the grasses, cattails and reeds. These plants are uniquely adapted to living in environments where their roots are consistently submerged. They grow densely around channels and areas of open water, forming a deep carpet of vegetation in the summer. In winter, this carpet becomes stiff brown stalks, roughly holding their summer forms, until they finally fall and decay in the spring growing season. Within these dense banks of vegetation, the invisible wetlands flourish. 

The inhabitants of the invisible wetlands are both permanent and temporary. Some organisms live permanently within the vegetation cover while others visit occasionally. 

The plant cover has many advantages for its residents. It hides prey from the detection and attack of predators and reduces a predator’s ability to quickly and quietly move in the dense thicket to catch their prey. The vegetation also provides an excellent source of shade, allowing organisms to shelter from the summer sun and heat. Similarly, the cattails provide shelter from strong winds in both the winter and summer, reducing the challenge of flying in heavy wind and mitigating the winter wind chill. Finally, the reed banks provide an ample source of plant matter for both hungry herbivores and animals seeking to build burrows and nests.

The permanent and temporary inhabitants of the invisible wetlands include a broad spectrum of organisms that use the amenities it provides in a wide range of ways. Water birds like the Virginia rail use the reeds to hide from predators like hawks and eagles. Birds like the Canada goose also raise young deep within them, benefiting from the ample building materials and shelter these plants provide. Frogs and other amphibians use the reeds to protect themselves from heat and predation while they mate and pursue the insects they feed upon. The insects utilize the reeds to shelter from the wind, from songbirds and from predatory insects that frequent more open areas.

The amount of time organisms spend in the reed banks varies greatly. Some spend most of their lives hidden in the cattails, foraging and reproducing, while others are more infrequent or seasonal visitors, returning only when resting or raising young. But no matter how much time creatures spend there, the thickets play a critical role in the lives of most wetland organisms. 

The invisible wetlands are, by definition, difficult for the humans to observe. Here are three easy ways that you can get a glimpse into this fascinating environment. 

Find a gap in the reeds or a small stream channel and kneel down to get a similar perspective to that the wildlife experience. From this vantage point, you can often see details in the water and plants you would miss from above and can gain a new conception of how wetland animals navigate and see their environment.

Use sound to explore the invisible wetlands. Stop and listen quietly for a few minutes. After a short period of silence, many animals, such as frogs and birds, that are disturbed by passers-by will resume their activity in the reeds, allowing you to experience the calls, croaks and rustlings they make.

Use binoculars to reveal more of the invisible wetlands and the organisms that live there. Stand still and watch the edge of stand of reeds or a gap within them. It may take several minutes of observing the same location, but soon you will begin to see small animals moving in the reeds — animals that would be unnoticeable to a more casual observer. 

In these simple and unobtrusive ways, you can gain a glimpse into the lives of the organisms that inhabit the otherwise mysterious world of the invisible wetlands. All this activity goes into making the invisible wetlands an often unseen but crucial part of the Riverwalk wetlands and the extraordinary biodiversity this ecosystem supports.

If you want to learn more about our fascinating Riverwalk wetlands, or want to get involved in protecting and educating others about them, please contact Pagosa Wetland Partners at pagosawetlands@gmail.com.