Have you seen robins in Pacific Beach? Robins are flocking to San Diego — and no one knows why

Tens of thousands of robins have invaded San Diego County this spring. This one chows down on pyracantha berries in Ramona.
(Tammy Kokjohn photo)

Bird watchers have spotted thousands of American robins throughout the county this winter feasting on berries -- a phenomenon that hasn’t occurred for decades


“When the Red, Red Robin (Comes Bob, Bob, Bobbin’ Along)” ... A lot of San Diegans these days may be singing that catchy tune recorded by Al Jolson in 1926.

American robins, seldom seen in San Diego, now seem to be everywhere.

The NextDoor online app, where local residents post items of interest, is teeming with observations:

  • We had robins in our backyard this past week for the first time ever! (University City)
  • We are so excited by the robins. Came home to a yard full of them about a month ago. (Bay Ho)
  • Last weekend there were hundreds in our yard. It was quite a sight! (La Jolla)
  • Is this in San Diego? I didn’t know we had robins here.”
  • “I haven’t seen a robin since I left Oregon 35 years ago.”
Robins visiting Point Loma gathered at this water feature in Holly McMillan's yard.
(Holly McMillan photo)

April Schug has lived in San Diego almost 66 years and says she never spied a robin until a couple of days ago when she walked into her Bird Rock back yard and about a dozen robins swooped up from her pond. “I thought I was re-living the movie, ‘The Birds.’ It was startling, yet they are so beautiful.”

Other locals posted photos of the orange-breasted bird with brownish-gray back and black hood (males), asking: “What is this bird?”

Yes, it is the American robin. And its uncharacteristic appearance here in such huge numbers has local ornithologists stumped.

“The robin glut has been going on since December,” reports Lesley Handa, an ornithologist on the board of the San Diego Audubon Society. “Some birders in the county have seen 1,750 in certain places. This is very unusual for this species.”

On one recent morning, Paul Lehman, who was longtime editor of Birding magazine and created bird range maps for field guides, counted about 1,500 taking flight at dawn from trees at the San Diego Zoo where they had roosted overnight.

He says friends have spotted other massive flocks in the Lake Hodges area near Escondido and in the Poway/Rancho Bernardo area.

The robin population is exploding in San Diego and has increased in other areas of Southern California and Southern Arizona, as well.

Has it ever happened before? Not in recent history.

Philip Unitt, editor of “Western Birds” and curator of birds at the S.D. Natural History Museum, says it’s the largest robin incursion on record in 50 years. The last time such giant robin flocks were sighted locally was in 1972-73 and, in even greater numbers, in 1961-’62 and 1957-’58, according to the annual Christmas one-day bird count here.

He says that since 2005 we’ve had very few robin sightings — probably limited to those in the small resident breeding population that began colonizing here, primarily in the mountains, in about 1940. But that population has dwindled over the past 20 years, Unitt says.

So, imagine bird watchers’ delight when a bird count Dec. 23 in Escondido recorded 695 robins, and a Dec. 27 count in Rancho Santa Fe logged 3,789. “The robins’ long downhill slide locally makes his year’s invasion all the more surprising,” Unitt says.

The experts don’t know the exact origin of these robins, who winter in large numbers in the Pacific Northwest and northern states, or why they came.

Is it stormy weather? Cold temperatures and snow? Scarce food and water supplies? It’s anyone’s guess. It could be all these things, and more — a perfect storm.

There long have been occasional sightings in the county of single robins or a few pairs of robins, explains Lehman, who goes bird watching every day. He estimates that as many as 50 to 100 breeding pairs are scattered throughout the county.

It’s not unusual to see a robin or two at higher elevations, such as in Julian, or the Palomar, Laguna and Cuyamaca mountains, he says.

But now they are flocking to areas such as La Jolla’s coast, Balboa Park, Point Loma, Del Cerro, Encinitas, Vista, Lake Hodges, Escondido, Chula Vista, and even the Salton Sea and Anza-Borrego Desert. They’re even being spotted in Baja California.

The explosion of these birds actually has a name. “The term for this phenomenon is ‘irruption,’ ” adds Jen Hajj, San Diego Audubon Society event coordinator. An irruption is a sudden change in population density. It tends to be a migratory event when northern birds go somewhere they’re not usually expected — often in search of food.

“It seems that everyone is scratching their heads on this one,” Hajj says. “We can name the phenomenon, but can’t really say why it is happening. All we can do is stand in awe of the mystery.”

“How many? Who knows?” Lehman says. “Tens of thousands,” he guesses. Unitt agrees.

Lehman checked in with colleagues in Northern California, Washington, Oregon, Vancouver, British Columbia and northern states where robins often winter to ask if they had fewer robins this year.

No, he was informed, winter robin populations were thriving there as well.

“Wherever they should have wintered, they didn’t like this year,” theorizes Lehman. Since American robins are extremely hardy and used to cold weather, he doesn’t believe dropping temperatures or increased snow would have fazed them.

“The usual explanation is lack of food,” he says.

There could have also been a stellar breeding season last spring/summer, and now there’s just a lot more robins in these flocks (but I think this is the least likely),” adds Nick Thorpe, who works at the Zoo and S.D. Audubon Society. “There’s a lot of variables in migration patterns, so it’s hard to know for sure why a bird would end up in a particular place in one particular year.”

Unitt theorizes they may be coming from northeast of us, from the Great Basin and Rocky Mountain states where there is a heavy snow pack this winter. Perhaps some of the robins’ fruit-bearing shrubs failed to produce this year.

Claudia Allen snapped a photo on Feb. 5 of robins drinking out of a decorative water trough in her La Jolla garden.
(Claudia Allen)

As for the stereotypical image of robins in the East and Midwest eating earthworms and grubs, that’s common in the spring and summer, but robins feed principally on berries in the winter, says Unitt.

In San Diego, they are devouring berries from Brazilian pepper trees, carrotwood trees, camphor trees, Hollywood junipers, pygmy palms, pyracantha bushes and toyon shrubs. Even after our recent rains, Lehman says he rarely saw them chowing down on worms.

However, Claudia Allen, who reported more than 100 robins descending on her yard south of UC San Diego on two recent days, said that, in addition to berries, they were pecking at something in the new mulch.

A lot of folks have noticed flocks of smaller crested waxwings mixed in with the robins. That is not unusual, Lehman says, because waxwings eat the same diet as robins, and they are regular visitors here in the winter.

When will the robin visitors depart?

“Who knows,” Lehman says. “It could be tomorrow, or they could stay until March.”

Will they come back next year? “History tells us not to expect invasions in successive winters,” Unitt says.

A best bet for those who have robins on their San Diego bucket list, is to venture out to the San Diego Zoo parking lot about 6:15 a.m., Lehman suggests. If they are there, sunrise is when they take off in huge flocks to hunt for food. They’ll come back just before dusk — if they do return.