Rare birds and rarely observed behavior: mutual preening strengthens bonds between mating pairs. The largest owl in North America, the great gray owl (Strix nebulosa) is a state endangered species, and Yosemite is one of the last sanctuaries for California’s populations. Researchers estimate there are only about 200 to 300 individuals in the state, and about 65% of that population resides in Yosemite. These majestic, stoic birds nest in the middle elevations (2,500 feet to 7,500 feet) of the park along the edges of forests and meadows. Perching quietly, they generally do not call attention to themselves as they quietly observe for prey to hunt such as voles, gophers, squirrels, and chipmunks. Learn more about great gray owls in Yosemite: https://www.nps.gov/yose/learn/nature/great-gray-owl.htm.