Keystone Species: How Wolves Saved Yellowstone & Why Mammoths Still Matter

Added: 2026-05-09

[00:00:00]What do Yellowstone's wolves and Ice Age mammoths [music] have in common? They were both capable of reshaping entire ecosystems and when they disappeared, everything changed.

[00:00:10]Throughout March of 1995, three packs of wolves would leave their acclimation pens in [music] Yellowstone's Lamar Valley. These 14 gray wolves relocated from Canada marked the return of an animal that had not stepped foot here in over 50 years. [music] In the early 1900s, people rapidly removed predators from ecosystems. At the time it was about safety and protection. [music] They didn't necessarily think about what these actions would lead to. The animals like elk that the wolves used to hunt saw rapid population explosions due to the sudden loss of the wild animals that kept them [music] in check. They overgrazed the landscape, especially young willow, aspen, and cottonwood trees near rivers and streams. The extended time spent near those riverbanks led to more trampled soil and disrupted root systems, [music] eventually leading to increased erosion, widened streams, and less clear, more sediment-filled water. And it didn't stop there. According to the National Park Service, the first beaver survey in 1921 counted 25 active colonies. [music] In 1953, they reported eight colonies.

[00:01:09]These numbers would continue dropping until the eventual reintroduction of beavers. Birds saw similar impacts due to the decrease [music] of their vegetation, and fish and insects were impacted by the changes to the rivers as well. For millions of years, predator and prey relationships shaped each [music] other, an evolutionary arms race that carved ecosystems into balance.

[00:01:28]When we removed the ones that scared us, bears, [music] wolves, cats, the consequences were felt across the entire food web. It's been over 30 years since the wolves were welcomed back to Yellowstone, and today the park is thriving. [music] Elk numbers have balanced out. Trees are growing tall again.

[00:01:46]Beavers are back, rivers are clear, and biodiversity is on the [music] rise.

[00:01:52]Even the local economy has benefited with thousands of visitors coming every year for a chance to [music] see the beauty that is this ecosystem. One keystone species reintroduced and the entire [music] system begins to recover.

[00:02:05]Yellowstone's story is one of healing, but just beyond the edge of history lies a story of silence, of giants gone and a landscape that faded with them.

[00:02:15]12,000 years ago, much of the northern hemisphere looked very different than it does today. The mammoth steppe was a cold, dry grassland where herds of mammoths roamed alongside steppe bison, wild horses, saiga antelope, camels, and their large counterparts like cave lions, dire wolves, saber-toothed cats, and giant short-faced bears helped keep that ecosystem [music] in balance. In the eastern stretches, you could even find cold-adapted hyenas and woolly rhinos. The mammoth steppe wasn't barren, it was full of life. [music] But no system, no matter how vast or diverse, is immune to disruption, and the mammoth steppe was standing on the edge of one. No single moment marks its collapse, but over time the giants began to vanish. Some point to the warming climate at the end of the last glacial maximum, but that it happened before and the animals in [music] the ecosystems had persisted. So, what made this time different? Perhaps it was the people, growing numbers, moving further into the regions, more sophisticated [music] hunting methods making them better able to take down larger animals.

[00:03:19]It's possible. Me, personally, I think it's more likely a combination of the two, [music] the two acting as a one-two punch that prevented the eventual recovery of these animals and that mammoth steppe ecosystem. Regardless, the mammoths were lost and the ecosystem, the mammoth steppe, it began to change. Without herds of giant megafauna to trample the snow, churn the soil, and knock down young trees, shrubs and forest began to spread. Grasses, once dominant, started to disappear. The permafrost, no longer as insulated and protected, began to melt a little bit faster. And slowly, the cold grassy plains that had stretched across continents transformed into what we see today, a patchwork of tundra, taiga, and silence. We didn't just lose the mammoth, we lost the world they helped build.

[00:04:08]But at Colossal, scientists are working to change that, and not just for the mammoth's sake. Asian elephants are the closest cousins of the woolly mammoth, sharing around 99.6% of their DNA. And they're keystone species in their own right. Where elephants thrive, ecosystems thrive.

[00:04:23][music] They knock down trees, creating open grasslands that support the grazing animals. They dig water holes that other species rely on during the dry season.

[00:04:32]Their dung spreads seeds and fertilizes the soil. That's important. Elephants are landscapers, gardeners, and engineers of their environment. [music] And yet, they're in trouble. Habitat loss, poaching, and climate change are all putting pressure on elephant populations. [music] But here's the hopeful part. The same technology is being developed to bring back mammoth traits [music] could help protect and preserve the elephants that we still have here today. When we talk about the past, it's not just about what we lost. It's about what we still have and the responsibility we have to protect it. Because when we protect keystone species, we protect entire ecosystems, [music] even our own. Wolves in Yellowstone, sea otters in kelp forests, beavers in wetlands, elephants across Asia and Africa, these animals are more than just symbols of the wild. They're the pillars that hold it up.