Moving like a buffaloIn a sentence: The North American bison (Bison bison) shapes their habitats through grazing and impact movements (wallowing, herding), resulting in landscape topographic structural changes, vegetation redistribution, and restructuring that impacts other species of vertebrates and invertebrates on the landscape. In an image:  Longer form thoughts: The North American bison is one of the more surprising species on my list of Aquatic Architects. These terrestrial megafauna create open water ponds on the prairie from wallowing behavior. Therefore, they have made it onto my list of animals that engineer or create aquatic structures. However, their behavior, their impacts on the landscape, the effects on other species, and their absolutely fascinating history require, I think, a broader explanation than simply speaking to aquatic architecture. As far as I know, bison don't go about their day considering how and what they will engineer. They engineer just through moving. They have two key behaviors that result in ecosystem engineering: 1) Discriminatory grazing (Towne & Hartnett, 1995; Knapp et al., 1999).and 2) wallowing (McMillan et al., 2000; Truett et al., 2001).. Discriminatory grazing - being a picky eater. Wallowing - bathing in dirt. Bison prefer green grass. As they navigate grasslands, they select the greenest stems, clipping the grass with their teeth. Grasses have different greening times and a tiny window of greening in the Great Plains. In chasing after the green, bison move rather quickly. Not spending too much time in any particular location for grazing, bison move vast distances, minimizing grazing impacts locally. This preference for green and the speed at which they move create a heterogeneous distribution of grasses. Short grass, tall grass, shrubs, and a diversity of species develop a diversity of microhabitats that specialists, such as many grassland bird species, can take advantage of. Many of these birds use bison hair to construct their nests (Coppedge, 2009; Wisentproject Kraansvlak, 2019). The warm, elastic bison fur is probably excellent for eggs for insulation and mechanical protection. I think a fun research study would be to access the thermo-mechanical properties of a bird's nest made out of bison hair to see how that might impact chick survival rates. Where are my ornithologists who took too many physics courses? The increase in small vertebrates also invites small predators - such as foxes and coyotes. Larger predators (grizzly bears, wolves, humans) also move in, attracted by large ungulates (deer, elk, pronghorn antelope, moose) who have benefited from the newly restructured grasslands. As bison move through the landscape, their shaggy coats pick up seeds. This allows them to gather and plant vegetation across the landscape. Many of these natural grasses have deep root systems. These deep root systems act as carbon sinks and stabilize the soil. I'm not a climatologist, but I am aware enough of the conversation surrounding our climate to confidently claim that the restoration of grasslands and reintroducing one of its key engineers could be a practical and critical step in cooling and stabilizing our climate. Our climate catastrophe is a many-pronged problem, and so must our solutions be. Behavioral side note: The biomechanics of how bison eat make them distinct from cattle (Bos taurus) that currently dominate our North American grasslands. Cattle grip and tear up grass root systems, killing the grass. While, as far as I can tell, this is primarily anecdotal, it is a pervasive claim amongst bison managers/ranches, meriting some note and probably more study. Studies on the Eurasian bison (a cousin of the N. American bison) have shown that because of their wide muzzles and muscular tongues, Eurasian bison can clip grasses closer to the ground, preventing disturbance to the root systems. Behaviorally, cattle are less discriminatory (making them easier to raise, but harder on the land) because they graze more uniformly, which decreases biodiversity. Bison also engage in wallowing behavior - particularly males in rut. Bison roll on the ground, bathing themselves in dirt. Through rolling, they often remove all vegetation from that location. These depressions then capture rainwater, fill, and usually become small ponds. These open-water ponds benefit other vertebrates on the landscape, allowing them to drink water. These small ponds (~ 1 m. to 2 m. wide, and ~ 20 cm deep, become microhabitats. These small ponds are home to frogs, snakes, birds, and insects. Because of the higher water content, the vegetation directly around and within the pond differs from the surrounding grassland. These small ponds also support groundwater recharge. While there are practical reasons why bison populations will not fully return to all of their natural ranges in our lifetime, perhaps one way we can compensate for this is by creating buffalo wallows throughout our prairies. Bison biomimicry can extend to more than just excavating ponds in the middle of grasslands; there has also been work done on moving cattle between pastures to mimic the natural movement dynamics of bison to achieve the same heterogeneous grazing patterns bison produce. Not only does the soundscape of a bison-engineered habitat have grassland birds, but it also has the croaks of frogs. Just listen to this video of a Bison wallow. Absolutely lovely. Eat more bison: One of the best ways, I would argue, to promote bison back onto their natural landscapes to engage in the engineering of grasslands and resulting trophic cascades, is to consume more bison. References:
1 Comment
12/19/2025 10:12:15 pm
Fascinating explanation of bison as powerful, underrated ecosystem engineers truly. Leave a Reply. |
AuthorJordan is a technologist, an Indigenous futurist, a beaver futurist, an animal enthusiast, a curious scientist, a compulsive engineer, and science storyteller. 
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