Pasadena’s bird-watching enthusiasts may be unable to gather in-person to mark National Bird Day on Tuesday, but they’ll be treated to more complex and intricate bird songs than ever, as avians have expanded their repertoires to fill the relative quiet created by the pandemic.

As the pandemic stretches on, its impact on bird life is being “widely studied,” according to Pasadena Audubon Society Program Director Lois Brunet.

Based on recent studies, “It seems birds are able to sing more complex songs with wider dynamic ranges now that urban noise is reduced,” she said.

And the change occurred quickly, Brunet added. “They adjusted right away.”

Unfortunately, local birders have been unable to meet up to go bird watching as a group since the start of the pandemic, she said.

“Pasadena Audubon typically runs about 100 field trips a year. These free public events are the heart and soul of our organization,” Brunet said. “New members typically come to us to find others to bird with. It’s the best way to learn about birds and to discover great birding haunts. We’ve of course had to call these off and we all miss the company of other birders.”

Monthly lectures on birds and conservation-related topics continued, but have moved online.

“We’ve had terrific attendance, with the added bonus of reconnecting with old members from out of state,” she said.

The organization’s elementary school Bird Science Program, which previously included two classroom visits and a field trip, has also been adapted to…