Sutro Bird Watcher: Steller’s Jay & California Scrub-Jay

August 28, 2017

Grab Your Binoculars!

 

Why is it that when walking the trails on Mt. Sutro the Steller’s Jay is seen and heard, while in neighboring gardens the California Scrub-Jay is prominent?

 

The evergreen, forested and hilly nature of Mt. Sutro is appealing to the Steller’s Jay while the more open nature of most backyard gardens appeals to the California Scrub-Jay. Both the Steller’s Jay and the California Scrub-Jay are members of the Corvidae family of birds. Corvids are known to be very inquisitive and verbal, to have complex relationships with other birds of the same species and to have an intelligence surpassing other birds and many mammals.

 

Steller's Jay

 

The Steller’s Jay is a large bird with a prominent black crest and hood, and with iridescent dark blue body feathers that shine in the sunlight. Pale blue lines above the eyes add detail to the face. The tail is long. Sixteen subspecies of Steller’s Jay have been identified. The name “Steller” is a tribute to Georg Steller a naturalist who discovered them on an Alaskan island in 1741, when exploring on a Russian explorer’s ship. 

 

California Scrub-Jay

 

The California Scrub-Jay head is rounded, lacking a crest. The adult California Scrub-Jay has a deep azure blue crown, neck, wings and tail. The throat is white. The chest is light gray with a blue necklace. A long, white eyebrow is prominent. The back is gray-brown. In shadow the blue color appears to be simply dark. This jay also has a long tail. Juveniles have more gray on the back than the adults. California Scrub-Jay and Woodhouse’s Scrub-Jay were considered a single species known as Western Scrub-Jay until 2016. The Woodhouse’s Scrub-Jay can be found in Arizona and Mexico in dry shrublands and pinyon forests. Its colors are more muted than the colors of the California Scrub-Jay.

 

Steller’s Jay

 

The Steller’s Jay is found along the north coast of California into Alaska, and far inland, in the Sierra Nevada and Rocky Mountains. The California Scrub-Jay is found along the Pacific coast from Canada to Baja. The latter jay is known for its association with the oak trees and dry scrub. The California Scrub-Jay will harvest acorns and cache them in the ground, often leading to the propagation of the oak.

 

Summertime is when both species of juvenile birds are begging for food from beleaguered parents. Listen and you might hear a baby cry that leads you to see a full sized bird that looks baffled closely following a more purposeful adult who is successfully finding food among the leaves, usually on the ground. The baby flutters, cries, is fed and demands more.

 

California Scrub-Jay

 

The bold behavior of the California Scrub-Jay is very entertaining to the human viewer, even without the benefit of binoculars. They can be seen interacting with each other, hopping and prancing about. Both jays hold a posture of attention with heads tilted at an angle. The mated pair raises young together, stay together throughout the year and can be seen defending their territory vigorously. Both jays are known for their various and distinctive calls that can pierce the surroundings. The Steller’s Jay is known as a mimic of sounds, including other birds (particularly hawks), animals and mechanical sounds.

 

Imagine my surprise when visiting Big Basin State Park near San Jose upon learning that these corvids are considered a nuisance! Why were my beloved and charming jays considered a threat? Research has shown that corvids have followed humans into picnic and camping areas of Big Basin where they had been unknown. In Big Basin State Park these corvids are now known to predate the nests of the Marbled Murlette, birds that nest in the high canopy of the redwood forest and feed in the ocean as much as 50 miles away. The Marbled Murlette was federally listed as Threatened under the Endangered Species Act in 1992. In Big Basin visitors are directed to must dispose of food trash carefully, to ensure that these corvids are not attracted by food scraps. I have learned once again, that the urban bird population is distinct from bird populations in wild and pristine areas. Read the Big Basin State Park brochure for more information >

 

P.S.; Many will erroneously call these jays a “blue jay”. In truth, the Blue Jay is only found east of the Rocky Mountains.

 

We are fortunate to share Mount Sutro, neighborhood gardens and parks with these beautiful, intelligent and entertaining birds.

 

Check out the links below for more information, including identification, life history and sounds:

https://www.allaboutbirds.org/guide/Stellers_Jay/id

https://www.allaboutbirds.org/guide/California_Scrub-Jay/id

https://www.parks.ca.gov/pages/540/files/BigBasinRedwoodsFinalWebLayout101816.pdf

Photos are from http://www.canstockphoto.com

 

 

 

 

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