The Ecological Impacts of Wild Horses
I want to start off this post by saying that the core mission of our project is to provide an unbiased synopsis of the wild horse problem. All three of us love horses, so sometimes it’s hard to look at their negative impacts, but without looking at all sides of the story, we can’t provide you (and ourselves) with the real story of what’s going on. So today we’re discussing the ecological impacts of wild horses and, as you can probably already tell, they’re not all that positive. I’d like to make it perfectly clear: we’re not trying to take sides on this issue. We want to give you all of the facts so that you can make your own informed decision on how you feel about this complicated issue. Alright, let’s dive in.
Effects on Vegetation
Let’s start with how wild horses impact plant life: in general, horses can change the type and density of plants where they graze. According a 2018 study, horses have a larger impact on forage than cattle, likely caused by the fact that they eat more than cattle. Additionally, the study found that horses tend to graze the forage down lower than cattle and wildlife, which alters the species richness and plant cover. Basically, it was found that horses have the greatest impact when it comes to forage height, meaning they graze their food lower and at higher rates than wildlife and cattle.
Horses and cattle can both have significant and harmful impacts when their populations are too high. With controlled grazing, effective management can be accomplished but this is difficult in areas with wild horses because they graze year-round and their population levels are hard to manage.
Area where horses were allowed to graze on the right, excluded from grazing on the left. This study was done in Sheldon National Wildlife Refuge in Nevada, in June 2012. The study specifically states that “horse use at this location was heavy and should not be interpreted to represent horse use across the entire area occupied by horses, because their forage use is highly [varied]”.
A Sagebrush Sparrow’s nest. Wild horses can negatively impact the health of sagebrush, which these birds rely on as their homes.
Effects on Soils
So because horses eat so much, they may travel more than cattle or wildlife to find food, increasing trampling on soils. Several studies have shown increased soil compaction and soil surface penetration resistance, and decreased soil stability, due to wild horses. This increases the risk of soil movement which can create bare ground and is more likely to be impacted by erosion. This change in the soil makes it easier for exotic plants to invade. Additionally, soil erosion can cause irreversible damage to plant communities. Essentially, due to the impact wild horses have on soil they could, over time, permanently affect the productivity and function of the rangeland.
Effects on Wildlife
The negative impacts that wild horses have on vegetation and soils can also negatively affect wildlife habitat. One study found that wildlife are attracted to high quality foraging areas over degraded habitats, providing evidence that wild horses have an indirect effect on wildlife by creating these degraded areas. The horses’ negative impacts on wildlife likely have less to do with them eating the same forage and more to do with the horses causing disturbance to the land through trampling. Horses also tend to limit the recovery of shrubs like sagebrush. In areas where horse numbers are unmanaged, they can negatively affect wildlife that rely on sagebrush for food or nesting.
Horses may also cause stress to wildlife through competition for water. Many studies have found that horses will prevent elk, pronghorn, and bighorn sheep from accessing water.
In the end, wild horses don’t appear to have a positive ecological impact. A lot of this has to do with a lack of proper management, which is ultimately due to our emotional stake in the issue: if we didn’t have an emotional connection to horses, we might manage them the same way we manage livestock or wildlife: by allotting them a certain amount of acreage and hunting, respectively. But horses are not livestock nor wildlife - I can’t imagine many people would want to kill or eat a wild horse. So they reside in a different category altogether, one that we’re not really sure how to manage. While the facts may not be easy information to take in, the science doesn’t lie and real change needs to happen before it’s too late to repair the land. We hope a solution can be found to responsibly manage horse numbers to maintain the health of the land and, ultimately, happily share the space we all want to use. No one owns public land, it is shared by ranchers, wildlife, hikers, bikers, and wild horses alike. One of the great beauties of living in America is our access to public land, but this space was created to be shared and we must view it that way.
We’re curious to hear your thoughts. Leave your comments below!
xoxo, the Wild Women