Robins are flocking to San Diego — including Point Loma-OB — and no one knows why
Bird watchers have spotted thousands of American robins throughout the county this winter feasting on berries — a phenomenon that hasn’t been seen in 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 — including the Point Loma-Ocean Beach area.
Social media is teeming with observations:
- Is this in San Diego? I didn’t know we had robins here.”
- Last weekend there were hundreds in our yard. It was quite a sight! (La Jolla)
- 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)
- “I haven’t seen a robin since I left Oregon 35 years ago.”
April Schug of Bird Rock has lived in San Diego almost 66 years and said she never spied a robin until a few days ago when she walked into her backyard and about a dozen swooped up from her pond.
“I thought I was reliving the movie ‘The Birds,’” she said. “It was startling, yet they are so beautiful.”
Claudia Allen reported more than 100 robins descending on her yard south of UC San Diego in La Jolla on two recent days.
Other locals posted photos of the orange-breasted bird with a brownish-gray back and black hood (males). “What is this bird?” they asked.
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,” said 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.”
“It seems that everyone is scratching their heads on this one. ... All we can do is stand in awe of the mystery.”
— Jen Hajj, San Diego Audubon Society event coordinator
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 said friends have seen 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.
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Has it ever happened before? Not in recent history.
Philip Unitt, editor of “Western Birds” and curator of birds at the San Diego Natural History Museum, said 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.
Since 2005, he said, there have been 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 said.
Thus, bird watchers were delighted when a Dec. 23 count in Escondido recorded 695 robins and a Dec. 27 count in Rancho Santa Fe logged 3,789.
“The robins’ long downhill slide locally makes this year’s invasion all the more surprising,” Unitt said.
Bird 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? Lower temperatures and snow? Scarce food and water supplies? It’s anyone’s guess. It could be all those things and more — a perfect storm.
There long have been occasional sightings in the county of single robins or a few pairs, said 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 said.
But now they are flocking to places such as Point Loma, La Jolla, Balboa Park, Del Cerro, Encinitas, Vista, Lake Hodges, Escondido, Chula Vista and even the Salton Sea and Anza-Borrego Desert. They’re also being spotted in Baja California.
“How many? Who knows?” Lehman said. “Tens of thousands,” he guesses. Unitt agrees.
“The term for this phenomenon is ‘irruption,’” or a sudden change in population density, said Jen Hajj, San Diego Audubon Society event coordinator. An irruption 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 said. “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.”
Lehman checked with colleagues in Northern California, Washington, Oregon, Vancouver, British Columbia, and northern states where robins often winter to ask if they’ve had fewer robins this year.
He was informed that winter robin populations are thriving there as well.
“Wherever they should have wintered, they didn’t like this year,” Lehman theorized. Since American robins are very 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 said.
“There could have also been a stellar breeding season last spring/summer and now there’s just a lot more robins in these flocks,” said Nick Thorpe, who works at the San Diego Zoo and S.D. Audubon Society, though he added that he thinks that’s the least likely reason. “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 snowpack this winter. Perhaps some of the robins’ fruit-bearing shrubs failed to produce this year.
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, Unitt said.
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 the recent rains, Lehman said, he rarely saw them chowing down on worms.
A lot of folks have noticed flocks of smaller crested waxwings mixed in with the robins. That is not unusual, Lehman said, because waxwings eat the same diet as robins and are regular visitors here in the winter.
When will the robins depart?
“Who knows?” Lehman said. “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 said. ◆
