By Robert Groos

California Scrub-Jay in flight.

Gather ye acorns while ye may,

Old Time is still a-flying…

With apologies to poet Robert Herrick, it is October in the oak woodlands: we have no rosebuds. Instead, we have acorns, and they are falling from the trees. It is an important time of the year for winged as well as quadruped acorn gatherers. Acorn Woodpeckers, Ground Squirrels, Western Gray Squirrels, as well as deer are all busy looking for acorns.

California Scrub-Jay holding a freshly-picked acorn with its bill.

California Scrub-Jays, too, are busy harvesting acorns. Their slightly curved bill is adapted specifically for harvesting and opening the seed’s hard shell. I enjoy watching them pull an acorn from a twig, hold it down on a branch with their toes, hammer it open with their sturdy bill, and pick the meat out.

California Scrub-Jay opens an acorn with its bill.

Scrub-Jays are impressive birds. Their posture is bold and aggressive. They move with purpose and determination, whether on the ground, in the trees, or in the air. Like a schoolyard bully, they swoop down to the head of the line at your seed feeder, screeching a warning to smaller birds to get out of the way. Scrub-Jays are the drill sergeants of the avian world.

California Scrub-Jay standing bold and vigilant.

Studies show that California Scrub-Jays, like other members of the Corvid family (crows, ravens, magpies, jays), are very intelligent. Watch them for awhile and you might conclude that they always seem to be up to something. And you would be correct in that conclusion. Their thoughts are not stuck in the present; they have a consciousness of passage of time, and they can plan for the future.

The storage of acorns is a good example of the California Scrub-Jay ability to plan and think ahead. They cache thousands of acorns in the ground each year. One study demonstrated that a single individual might remember the location of up to 200 different caches, weeks, even months later. If an individual believes that a competitor is watching with intent to steal the acorn (evidence of “theory of mind”), the bird is clever in the way it goes about hiding the prize: the bird might pretend to place an acorn in the ground and cover it up, but in fact it flies away with it. Or, it might come back later to retrieve the acorn and move it elsewhere.

California Scrub-Jay caching an acorn in the ground.

Many of the acorns not eaten by deer, squirrels, or the California Scrub-Jays themselves, sprout and become the next generation of oaks in our woodlands. Indeed, we can thank the California Scrub-Jay for planting acorns uphill from the parent tree, thereby increasing the acreage where oak trees grow.

So consequential is the role that California scrub-jays play in our ecosystem that they are considered a keystone species. Don’t you love those birds?

Keep birding,
Robert Groos
For more from Robert Groos, visit:
robertgroosphotography.com


Robert Groos is a published photographer and keen observer of nature who lives in Yosemite Lakes Park. He shares some of his outstanding images of our local feathered friends along with some tidbits of interesting facts about each. We hope you enjoy them as much as we do. 

Previous posts:
Killdeer
Great-tailed grackle
What’s good for the goose
It’s nesting time
Wild turkeys on parade
The Pied-Billed Grebe
Hunchback of YLP: The black-crowned night heron
The bluebird
Talking turkey
The secret world of the phainopepla
Acorn woodpecker 
Oak titmouse
Swallows
White-breasted nuthatch
California quail
Bald eagle
Western kingbird
The turkey vulture