--- title: Wolves in Yellowstone, beavers in Britain and bringing nature back — a lesson of Mova's school · trees and pragmatics description: «Wolves in Yellowstone, beavers in Britain and bringing nature back», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: By the 1920s every wolf in Yellowstone Park in America had been killed, and without them the elk grew b --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Wolves in Yellowstone, beavers in Brit… # Wolves in Yellowstone, beavers in Britain and bringing nature back Lesson 283 of the biology course of Mova's primary school: 16 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/0/) — By the 1920s every wolf in Yellowstone Park in America had been killed, and without them the elk grew bold, stood by the rivers and munched the young willow and aspen trees. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/1/) — In 1995 and 1996, 31 wolves were brought back from Canada; the elk had to keep moving again, and in some places young trees could grow, which helped beavers and birds. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/3/) — The famous video says the wolves «changed the rivers», but scientists say the story is more complicated, because bears, people and weather mattered too; still, the main lesson holds: top predators shape the whole web. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/4/) — Bringing missing animals back and letting nature run itself again is called rewilding, and in Britain it has brought back beavers, white storks and nightingales. - [5](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/5/) — Wolves were killed out of Yellowstone by the 1920s, and 31 wolves were brought back from Canada in 1995 and 1996; without wolves, elk ate young trees along the rivers, and with wolves back, elk moved more and some trees could grow again. - [6](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/6/) — Wolves helped willows and aspens in some places, which helped beavers and birds; scientists say the story is more complicated than «wolves changed the rivers», because bears, people and weather also mattered. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/7/) — A trophic cascade is a change at the top of a food chain that ripples down: wolves eat elk, elk eat trees, and trees shade streams and feed beavers. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/8/) — Sea otters, sea urchins and kelp are another trophic cascade. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/9/) — Wolves sometimes kill sheep and cattle near parks; farmers are paid for losses, and guard dogs, fences and lights help keep wolves away, so that farmers and wild animals can live side by side. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/10/) — Beavers were hunted out of Britain about 400 years ago and have been returning; official releases into the wild in England were reported from 2025. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/11/) — Beaver dams slow floods, clean water and make ponds full of life, though some farmers worry about flooded fields. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/12/) — Lynx are shy wild cats that eat deer and are not known to attack people; some people want them back in Scotland, some farmers fear for their sheep, and it is debated carefully. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/13/) — Rewilding means letting nature run itself again, often by returning missing animals; at Knepp in England a farm was left to go wild, and storks, turtle doves and nightingales came back. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/14/) — White storks nested in England again in 2020 for the first time in hundreds of years, after birds were bred and released; in many countries storks on rooftops are a sign of good luck. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/15/) — Wild wolves are shy, and attacks on people are very rare; old stories like Little Red Riding Hood come from times when people feared wolves and lost livestock. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/283-wolves-in-yellowstone-beavers-in-britain-and-bringing-nature-back/16/) — Wolves howl to call their pack and warn other packs, at any time of night or day; they point their heads up because the sound carries further, and the moon has nothing to do with it. - ← previous: [Comeback stories: bald eagles, humpback whales, condors and the kakapo](https://md.mova.elamur.ai/free/en/corpora/school/biology/282-comeback-stories-bald-eagles-humpback-whales-condors-and-the-kakapo/) - next →: [Conservation heroes: Attenborough, Goodall, Carson, Maathai and the rangers](https://md.mova.elamur.ai/free/en/corpora/school/biology/284-conservation-heroes-attenborough-goodall-carson-maathai-and-the-rangers/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)