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How Wolves Change Rivers

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When wolves were reintroduced to Yellowstone National Park after a seventy-year absence,

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the most remarkable thing happened.

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They changed the behavior of the rivers.

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The wolves hunted the deer, which had been overgrazing the valleys.

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Vegetation grew back. Trees grew. Songbirds returned.

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The roots of trees stabilized the riverbanks.

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The rivers began to meander less. The channels deepened.

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The wolves, small in number, transformed the entire physical geography of the park.

How Wolves Change Rivers

Learn English with Sustainable Human (2014). Watch, read the transcript, practice pronunciation and complete grammar exercises. How Wolves Change Rivers

Full Transcript

When wolves were reintroduced to Yellowstone National Park after a seventy-year absence, the most remarkable thing happened. They changed the behavior of the rivers. The wolves hunted the deer, which had been overgrazing the valleys. Vegetation grew back. Trees grew. Songbirds returned. The roots of trees stabilized the riverbanks. The rivers began to meander less. The channels deepened. The wolves, small in number, transformed the entire physical geography of the park.

Traducao (Portugues)

Quando os lobos foram reintroduzidos no Parque Yellowstone após setenta anos de ausência, a coisa mais notável aconteceu. Eles mudaram o comportamento dos rios. Os lobos caçaram os cervos, que estavam pastando demais nos vales. A vegetação voltou. Árvores cresceram. Pássaros canoros retornaram. As raízes das árvores estabilizaram as margens dos rios. Os rios começaram a serpentear menos. Os canais se aprofundaram. Os lobos, poucos em número, transformaram toda a geografia física do parque.

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