Here are just a few of the avian species you might catch sight of during your Yosemite vacation.
Among the more common birds that visitors see at Yosemite is the Stellar’s jay. You’ll be able to pick it out by its vivid blue feathers, which interestingly, have no blue pigment in them. How does this work? Feathers, like fingernails are made of keratin. As the keratin molecules grow inside each cell, they create a pattern, and when the cell dies, a structure of keratin interspersed with air pockets remains. As sunlight hits one of these feathers, the keratin pattern makes the red and yellow pigments cancel each other out, allowing the blue wavelengths to reflect back.
In addition to their blue color, the birds are marked by a long, thick bill with a slight hook at the end and a triangular crest of feathers on their head. They have dark brown eyes, a fan-shaped tail and live about 10 years. Their wingspan stretches 12-17 inches.
You’re likely to see these beautiful birds around picnic areas and cafeterias, where they’re hoping to steal a snack or receive a handout. Remember that it’s illegal to feed wild animals in a national park, so don’t give them a bite no matter how loud they squawk.
Both bald eagles and golden eagles live in Yosemite, and both species have a special protection status. Members of the raptor (bird of prey) family, they use their long talons and hooked bills to capture and tear food apart. They have excellent vision for locating prey.
Bald eagles are typically found near large bodies of open water with an abundant food supply and old-growth trees for their large nests (the nests are typically 5-6 feet in diameter and 2-4 feet tall). Males and females look the same, except the females tend to be 25 percent larger than the males. Their beak, feet and irises are bright yellow; their legs are feather-free; and their highly developed hind-toe talon is used to pierce the vital organs of its prey while the unlucky dinner-to-be is held immobile by the front toes. Bald eagles are most likely to be seen at lower elevations in the Yosemite region and they have been reported as nesting at Bower Cave, Mariposa County.
With a wingspan reaching 6-7 feet, the golden eagle is the largest of Sierran land birds. The birds are marked by dark brown coloring that becomes paler and more golden brown on the top and back of the head. They cry out with a single, loud note, which is sometimes repeated several times in quick succession. Look for them in the western foothill belt, rather than in the higher mountains. They are most often seen soaring near rim of Yosemite Valley.
Formerly an endangered species, peregrine falcons usually nest in granite cliffs and walls in Yosemite Valley and the Hetch Hetchy area of the park. In fact, some rock-climbing routes including Half Dome are off-limits to climbers during the falcons' nesting season, usually from March to July. About the size of a common crow, peregrine falcons (also known as duck hawks) can have a wingspan of up to four feet long. they can sometimes be observed diving at amazing speeds of up to 200mph as they hunt for prey, mostly smaller birds.
Interestingly, female peregrine falcons are typically 30 percent larger than males. Both sexes are slate gray or blue-black on their backs, with banded white underparts and a distinctive black mustache visible on their whitish cheeks. The name peregrine, which is Latin in origin, means traveler or wanderer, which probably refers to the fact that this falcon has one of the longest migration routes in the Americas.
The Western tanager provides a cheery, bright spot of color in conifer forests throughout the western U.S. With its reddish-orange head, yellow underbelly, and the brushed white and yellow markings on its blackish wings, the male of the species is easily recognized. Interestingly, the red pigment seen on its head comes not from its genes, but from its diet of mostly insects that feed on plants.
Females do not share this red pigment; also, they have duller yellow underbellies and dark gray wings. During summer, Western tanagers are found from Texas all the way up to the Northwest Territories of Canada. In winter, most migrate to Latin America, although some only fly as far as Southern California.
As you hike through the conifer forests of the Sierra Nevada, you might wonder what on earth is making all that racket! Chances are, if it's not a black bear ripping up a log looking for an insects, it's a male blue grouse calling out with low-pitched hoots for a mate as he displays nearly two dozen tail feathers and struts around, or else that same bird making whirring sounds with its wings as he hops and flies around.
About the size of a chicken, the male of the species is typically blue-gray in color with a black tail, while females are smaller and brownish colored. The habitat of the blue grouse ranges throughout the mountains of the western U.S. In Yosemite, blue grouse have been spotted up to 11,000 feet in elevation.
Great Gray Owl
An endangered species in California, great gray owls are seldom seen by park visitors, although you may hear the owl's hoots echoing through upland forests. Scientists estimate that there are only 40 great gray owls currently living in Yosemite National Park, which represents the southernmost limit of the species' habitat.
Your best chance of seeing one is in the middle elevations of the park, especially on the border between forests and meadows. You can recognize them by their gray color and the distinctive shape of their rounded faces, as well as their lack of ear tufts. They also have a small black-and-white "bowtie" directly under their facial discs. Although great gray owls are the tallest (over two feet high) and have the longest wing span (up to five feet) of any North American owl, their small feet make them less skilled hunters.