Commentary: Can the Sierra Nevada bighorn dodge extinction? It may mean reining in another wild animal

The high peaks of the southern and central Sierra Nevada are home to a unique and endangered animal, the Sierra Nevada bighorn sheep. John Muir called them "the bravest of all the Sierra mountaineers," and indeed they have weathered both ancient and modern climate extremes, human-introduced disease and other existential threats across the centuries. But the greatest danger they face today may be from another native species.