If one late summer evening, you look out across Monterey Bay and notice a dark, churning cloud just above the water, you might be seeing sooty shearwaters. These grayish-brown seabirds swoop and splash in enormous feeding frenzies that can consist of hundreds of thousands of birds.
Sooties, as they’re also known, fly up to 40,000 miles each year in one of the longest known animal migrations on Earth. They breed in the Southern Hemisphere near New Zealand before flying a figure-eight pattern up through the Pacific, feeding in the Northern Hemisphere.
Up to a million of them stop by the Monterey Bay each year to feast in the rich waters of the California Current. In dramatic displays, they dive into the water to chase prey as deep as 200 feet below the surface.
“They’re often seen in the evenings in late July, August and September, and a bunch of other birds join them in these evening feeding frenzies, like elegant terns and parasitic jaegers, brown pelicans,” says Alex Rinkert, project director for the Breeding Bird Atlas Project with Santa Cruz Bird Club. “It’s really fun to watch.”
Sooty shearwaters are some of the most conspicuous fall visitors to pass through Santa Cruz County, but they’re hardly the only ones. The mix of rocky coastline, marshes, forests and grasslands attracts huge numbers of migrating birds to the area each year.
“We’re a small piece of California, but given how small we are, we have incredible diversity of habitat,” says Richard M. Lange, an avid bird-watcher—or birder—since 2006. “There’s almost too many birds to name in terms of what to be looking for.”
Lange enjoys finding unusual warblers in the fall and watching for birds outside their typical ranges, known as vagrants. He recalls one memorable instance in September of 2012 when birders in Watsonville found the second Common Cuckoo ever seen in North America. Unexpected moments like these keep people hooked.
“There’s always something more to learn, something more to observe,” says Nanci Adams, a lifelong birder. “We’re incredibly lucky,” she says of the areas surrounding Monterey Bay. “We get a wide variety of birds, but also we get some amazing vagrants.”
Adams started birding in South Dakota as a teenager and has continued for more than six decades. For the past several years, she has taught classes on birding basics through Watsonville/Aptos/Santa Cruz Adult Education. She has watched both bird and birder populations change.
“This year, there’s been a huge influx of new birders, and I think a lot of it has to do with Covid,” she says. “They were at home, and they started noticing their birds, and so they decided to learn about birds.”
You don’t need a fancy pair of binoculars or encyclopedic knowledge to get started. Websites like eBird show illustrated checklists of what species to look out for. And several groups around the Central Coast host guided walks and social events.
Aside from her classes, Adams recommends Watsonville Wetlands Watch and the Nature Center at Ramsay Park as resources for learning about local birds and migrations. The Santa Cruz Bird Club and the Monterey Audubon Society also arrange walks and provide good starting points.
Odd birds in odd places
Jonathan Pilch, the executive director of Watsonville Wetlands Watch, encourages anyone who’s interested to explore the nine miles of accessible trails around the Watsonville Slough System. At over 800 acres, it is one of California’s largest remaining coastal freshwater wetlands.
“There’s a lot of different access points, and each of them offers unique experiences,” he says. Both the Watsonville Wetlands Watch website and the Watsonville Public Works website offer trail maps, and the Wetlands site also includes colorful bird, plant and fish guides.
“The Monterey Bay, in general, is really unique,” he says. “There’s Watsonville sloughs, there’s also Elkhorn Slough. There are other smaller areas in northern Santa Cruz County … within Santa Cruz County, they’re an incredibly unique resource in terms of how big and expansive the habitat areas are.”
In addition to looking for seasonal bird species, Pilch enjoys watching how the overall habitats change with the seasons. In the fall, previously submerged areas of the wetlands dry down into mudflats. These changes bring in different types of plant and animal species.
“As the mudflats are exposed, you have migrating shorebirds that come into the slough system that are not there throughout other times of the year,” he says. “Different types of plovers and sandpipers and other species like that.”
The shifts happen quickly. You can walk the same trail a few weeks apart and see a completely new environment.
“Every day is different,” says Rinkert. “Even if you visit the same place at the same time, you’re always going to see something different than what you did previously. And that’s what keeps it interesting, in part at least.”
For many birders, the pursuit becomes more than a hobby. In addition to making simple walks feel like a treasure hunt, it becomes a way to build community and changes how many of them view the spaces around them.
“It’s a way to understand the world in a nonhuman way,” says Lange. “These creatures have been living in the habitat and engaging in it and manipulating it and transforming it in some ways for millions of years, and we’re more recent arrivals on the scene.” He says human activity also begins to stick out.
“You see degraded habitat and things that used to be there that are now removed, that you can only imagine the change that that brought to the birdlife. For example, huge swaths of the San Joaquin Valley were once just a giant marsh. That’s obviously been dried up and engineered for agriculture.”
Climate change and more intense wildfire seasons provide another example. Some local birders expect that last year’s fires will have an impact on this year’s migrations. Lost habitat and food resources could push birds onto new routes.
“Part of it is the possible inability to stop at a particular place to refuel and then move on,” says Adams. “If a bird is forced to fly farther distances than it ordinarily would without refueling, that can result in loss of muscle. So, it’ll be interesting to see what happens with birds like our yellow-rumped warblers or Townsend’s warblers, etc. that come from the north for the winter.”