Researchers find donkeys and wild horses dig desert watering holes, vital for the entire ecosystem
Research on wild horses and wild donkeys in the American Southwest shows that they dig desert wells with their hooves in the soft sand of riverbeds, creating a network of additional freshwater sources for creatures native to the region.
This discovery threw a key into the mainstream wisdom that wild equines, which were introduced by the Spaniards, are pests that should be eliminated – as the scientist behind the research suggests they could perform a vital function once performed by mammals now extinct from the Pleistocene.
In modern conservation, if an animal shows up where it did not live a few hundred years ago and thrives there, it is generally considered invasive. Invasive species are almost always seen as a threat, with animals like foxes, cats, goats, mice, sheep, pigs, cane toads, rats, carp and others terrorizing delicate ecosystems to Madagascar, the Galapagos and Australia, to name a few examples. .
The ecosystems of the Sonoran and Mojave desert currently host 95000 horses and wild donkeys, which are considered invasive pests that outperform other native herbivores, and suppress or trample native plants.
The conservation doctrine would say they should be exterminated or removed, but sometimes it’s more complex than that, and Erick Lundgren of Aarhus University in Denmark has shown that the eagerness of desert wildlife to drink of these equine wells should be taken into account before making decisions about the future of the species.
Lundgren found that 59 different species frequented the waterholes and that the species diversity around them was 64% higher than the ecosystem’s average of one square kilometer.
“Equine wells greatly reduced the isolation of water features, reducing mean nearest neighbor distances between water features by an average of 65%, and at most 99%,” wrote Lundgren and his co-authors in the article they Posted in Science.
Monitoring four different sites in the Sonoran and Mojave Deserts, and sampling over 3,258 trap nights from 2015 to 2017, Lundgren found bobcats, javelina, mule deer, scrub jays, and 55 other vertebrates. having a drink.
“There was a cacophony of organisms,” he said New scientist.
Digging water is a common behavior among large mammals around the world, and in Africa, elephant water wells are a gift to the surrounding species. Some animals, such as the elephant, beaver, and bison, are called “ecosystem engineers” because they shape their environment so dramatically that the flora and fauna that live there depend on it and await their impact. and have adapted to accommodate or operate it.
In his article, Lundgren postulates that American wild equines should be categorized as ecosystem engineers.
AFTER: Farms in the UK have saved this magnificent Duke of Burgundy butterfly from extinction
“By altering the abiotic environment around them, some organisms can really greatly facilitate other species and processes,” Lundgren said in a recent interview with Science. “The most notable aspect of deserts is the scarcity of water, and these animals can really improve its availability during droughts and during hot summers when natural water sources tend to dry up.
A role to play
Questions like if the presence of wild equines has changed the landscape in a positive way, what really constitutes an invasion and how far is it measured, and if our role is to constantly try to preserve what is there now, knowing that 99% of all species are extinct, and Earth’s history has seen constant change, are common in mammalian conservation.
RELATED: World’s oldest wild bird named Wisdom hatches another chick at 70 (WATCH)
In another of Lundgren’s papers, the author points out that since the Pleistocene, a wide variety of global megafauna have disappeared in many types of ecosystems. The services, or engineering of these species performed on the landscape for the benefit of the many animals and plants that still exist today, are largely a mystery.
Yet in numbers, the introduced megafauna have restored about 15% of the estimated Pleistocene megafauna populations worldwide.
Nowhere is this perhaps more distinct than in North America, which had not only prehistoric pachyderms in the form of the juggernaut, but also hyenas, sprinting cougars, the largest bear of all time, and, interestingly, several species of wild horses.
“The recent and ancient extinctions and range contractions of megafauna, along with the loss of their distinct ecological functions, have led to much modified modern landscapes,” he writes. “Although the introduced megafauna has primarily been studied as a threat to conservation objectives, a growing body of evidence suggests that it counteracts past losses and could replace lost ecological functions.”
CHECK: Check out this interactive map showing all of the conservation lands near you in the United States
Could the desert animals seen in Lundgren’s study be reacting to a function that the ancestors of these modern donkeys and horses performed on the landscape tens of thousands of years ago? It’s a question that makes you think, a question that Smithsonian the details touched the community in different ways, with some choosing to stay with current doctrine, and others reconsidering the pest status of wild American equines.
SHARE this story with friends who are thirsty for good news …