Just outside the San Diego Natural History Museum at Balboa Park, Ryan Terrill approaches the nearest tree and calls out to birds using a sound called “pishing.”
Almost immediately, several small, olive-green songbirds reveal themselves from the leafy branches.
“So this here is an Orange-crowned Warbler,” Terrill said, pointing to one that hopped furthest down a tree branch. “What we believe is that (pishing) mimics noises that baby birds make in the nest when there’s a predator nearby. So other birds will all come and look for the predator, or they’ll try to gang up on it.”
Birding in Balboa Park isn’t necessarily part of Terrill’s new job as The Nat’s curator of ornithology. But as a lifelong bird-watcher, he prefers to start the workday that way.
“Most mornings, you know, (I) show up early and bird around the park a bit before work for my own enjoyment. But also to document what’s around,” he said on Tuesday before the museum opened to the public. “I’ve already seen almost 75 species of birds just here in the park.”
Terrill joined The Nat’s 116-year-old Department of Ornithology about a month ago, where he oversees a collection of nearly 53,000 bird specimens. He replaced longtime curator Philip Unitt, who retired in February.
“Phil built a lot of really cool stuff that I’d like to preserve,” he said.
Organizing species by plumage, the way Unitt did, is among them.
“You have all the young birds together, all the adult males, all the adult females, each subspecies together,” said Terrill. “And that's really cool for me actually, because each plumage is together.”
He said he’s excited to add new collections, including cataloging birds with their wings spread. Otherwise, you miss a lot of data, Terrill said.
“You notice the wings are closed, and there's a lot of feathers on the wing, and a lot of the interesting stuff that happens with a lot of these, like, different molt strategies,” he said. “The variation is within the wing.”
Terrill previously served as the science director for Oregon’s Klamath Bird Observatory and has spent his career studying birds of the West Coast and parts of the Americas. Of all his research, feathers are his muse.
“Studying the evolution of feathers, especially studying their functions, can tell us a lot about how birds live.”
In San Diego County, often called the “birdiest county in America,” there are plenty of places to see how birds live.
“Right here in San Diego, we can go up to the mountains, we can go over to the desert, we can go to the coastal chaparral, we can go to the ocean,” said Terrill. “And it would be completely different communities of birds. And Baja is very much the same way.”
His new role is also a change for the museum. Ornithology is now its own department at The Nat. Unitt had overseen ornithology and mammalogy. The museum said the change is part of its commitment to studying the hundreds of species recorded in the region.
“This is a really special region for birds,” Terrill said. “A lot of it is because of the diversity.”
With a warming planet, it’s perhaps more important than ever to learn how and where birds fly.
“This one here was collected in Death Valley at Stovepipe Wells, on the sewage pond,” Terrill said while holding a specimen of a tiny seabird called a Wedge-rumped Storm-Petrel. “Certainly not where that bird wants to be, which is why it died. And this is one difference we’re seeing with climate change is these hurricanes starting to make more landfall and bringing these weird, you know, tropical seabirds inland. There's one of these here, at least one of these heat waves Salton Sea right now.”
Marine heatwaves, including an ongoing one in the Pacific Ocean, have been wreaking havoc on seabirds. For months, temperatures all along the West Coast have risen 3 to 4 degrees Fahrenheit above normal. On Tuesday, the ocean surface temperature off the La Jolla coast was 73 degrees Fahrenheit, one of the hottest on record for that day, according to the Shore Stations program at UC San Diego's Scripps Institution of Oceanography.
Those warm ocean temperatures are leading to large bird die-offs, and with a “super” El Niño winter, Terrill said he expects to see more.
“One of the reasons California is such a seabird hot spot is because we have this cold water current running north to south on the coast and a lot of upwelling,” he said. “So this deep, cold, nutrient-rich water gets brought to the surface and there's a lot of food. As the water gets warmer, less of that happens and there's less food.”
Seabirds have to wander farther to try to find food, he added, as he picked up a Nazca booby, or a large seabird, from the department’s collection. “This is a bird that was completely unrecorded in California prior to 10 years ago.”
Terrill said he hopes to continue his research into how climate change influences birds in Southern California and Baja California. He also plans to build a feather lab at the museum and study where birds fly to grow new feathers in the border region.
“What is the evolutionary history of these different strategies birds used for molt,” he said. “What are some of the ecological reasons, like why do different birds replace their feathers in different ways? And I realized that there was not a lot of research into those sort of why questions.”
To see some of the museum’s bird collections, he suggests booking a backstage tour. The Nat’s Expedition Baja and Coast to Cactus exhibits also include bird content.
And, he added, he’s also thinking about bringing public bird walks to Balboa Park.