San Francisco Chronicle

With less need to yell, birds’ singing is best in decades

- By Nora Mis­hanec

It was just af­ter sun­rise at Lo­bos Creek in the Presidio, and or­nithol­o­gist Jen­nifer Phillips was crouched low in the dunes, wait­ing for spar­rows. She inched for­ward, mi­cro­phone in hand, the early morn­ing si­lence bro­ken by bird­song and the dis­tant rum­ble of traf­fic.

On that morn­ing and many oth­ers since the start of the pan­demic, Phillips roamed the Presidio’s coastal sage scrub in search of white­crowned spar­rows, one of the Bay Area’s most com­mon avian in­hab­i­tants, known for its dis­tinc­tive, trilling war­ble.

Phillips was as­ton­ished by what she heard. The birds sang more softly in the rel­a­tive quiet of

the pan­demic-stricken city. They be­gan us­ing a lower reg­is­ter — a more se­duc­tive trill — that hadn’t been recorded lo­cally since the 1950s.

As the hum of hu­man ac­tiv­ity di­min­ished, the birds filled the si­lence with ever­more com­plex songs, their trills rein­vig­o­rated by the ab­sence of ur­ban noise.

The softer songs sig­nify just how quickly birds adapt to changes in their en­vi­ron­ment, a trait that has broader im­pli­ca­tions for their sur­vival in ur­ban spa­ces. No longer strain­ing to be heard over the din of traf­fic, the singing spar­rows were better able to at­tract mates, ward off ri­vals and de­fend their ter­ri­tory.

“When they sing softer, they can sing a wider range of notes, a sweeter song you might say,” ob­served Phillips, a re­searcher at Cal­i­for­nia Polytech­nic State Univer­sity San Luis Obispo. She col­lected sim­i­lar record­ings of the spar­rows at Point Reyes Na­tional Seashore and the Berke­ley Ma­rina, in ad­di­tion to the Presidio in San Fran­cisco.

Phillips and her col­lab­o­ra­tors at Cal Poly may be the first re­searchers to doc­u­ment the coro­n­avirus pan­demic’s im­pact on songbird be­hav­ior. Their re­search, pub­lished in the jour­nal Science this year, found that the spar­rows sang about 30% qui­eter dur­ing the pan­demic com­pared to pre­vi­ous decades.

“It’s pretty ex­cit­ing that they re­sponded so fast to the sud­den change in the sound of the city,” she said.

The find­ings could have broad im­pli­ca­tions be­yond birds. Con­ser­va­tion ef­forts have his­tor­i­cally fo­cused on restor­ing lost an­i­mal habi­tats, but have rarely con­sid­ered the detri­men­tal ef­fects of ur­ban noise. It’s a factor worth con­sid­er­ing, Phillips said, es­pe­cially as Cal­i­for­nia con­tem­plates a fu­ture full of elec­tric cars.

“Other birds that have been driven out of ur­ban ar­eas could be brought back if more peo­ple drove quiet cars,” Phillips said.

It’s not just birds that stand to gain from city plan­ning that takes noise into ac­count, said Clay An­der­son, an avid birder and youth co­or­di­na­tor for the Bay Area Audubon So­ci­ety.

“We all ben­e­fit from be­ing qui­eter,” he said.

An­der­son is a fre­quent vis­i­tor to Oak­land’s Martin Luther King Jr. Re­gional Shore­line, known in birder lingo as his “patch.” He’s no­ticed more peo­ple turn­ing to na­ture as a refuge dur­ing the pan­demic, but he wishes the Bay Area’s 7 mil­lion hu­man in­hab­i­tants thought more about their daily im­pact on the an­i­mals around them.

White­crowned spar­rows are good at adapt­ing to hu­man ac­tiv­ity, but their ubiq­uity should not be taken for granted, An­der­son said.

He cited the tri­col­ored black­bird and the pas­sen­ger pi­geon as just two ex­am­ples of bird species that ap­peared to thrive in the bus­tle of the Bay Area be­fore dy­ing off in droves. The nowex­tinct pas­sen­ger pi­geon was once the most abun­dant bird in North Amer­ica. The tri­col­ored black­bird, once a Cal­i­for­nia main­stay, is listed as an en­dan­gered species.

For now, the spar­rows are flour­ish­ing. But the re­newed com­plex­ity of their songs may be short­lived. Traf­fic has started creep­ing back to prepan­demic lev­els as Bay Area res­i­dents ven­ture out amid re­open­ing ef­forts and stay­ath­ome fa­tigue.

The spar­rows that hatched dur­ing the pan­demic, how­ever, may re­tain their full range of singing abil­ity, Phillips said. Young birds learn the war­bling trills of their par­ents and neigh­bors dur­ing the for­ma­tive months in the nest.

“They crys­tal­lize as singers and that’s the song they sing for the rest of their lives,” Phillips said.

The ques­tion is whether that will ham­per the young spar­rows come spring, when the world may have re­turned to its loud, prepan­demic rou­tine.

“Will they be able to breed suc­cess­fully singing songs mis­matched to their habi­tat?” she said. “Or will they ad­just?”

 ?? Pho­tos by Scott Straz­zante / The Chron­i­cle ?? A white­crowned spar­row takes flight. Re­searchers think the birds’ songs are more com­plex in re­sponse to qui­eter sur­round­ings.
Pho­tos by Scott Straz­zante / The Chron­i­cle A white­crowned spar­row takes flight. Re­searchers think the birds’ songs are more com­plex in re­sponse to qui­eter sur­round­ings.
 ??  ?? Clay An­der­son, youth co­or­di­na­tor for the Bay Area Audubon So­ci­ety, looks for white­crowned spar­rows while bird­ing at the Martin Luther King Jr. Re­gional Shore­line in Oak­land.
Clay An­der­son, youth co­or­di­na­tor for the Bay Area Audubon So­ci­ety, looks for white­crowned spar­rows while bird­ing at the Martin Luther King Jr. Re­gional Shore­line in Oak­land.

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