Blog Posts Archive - Page 22 of 137 - Golden Gate Bird Alliance

Dr. Chela Zabin counts oysters at Pier 94

Oysters, Climate Change, and Pier 94

By Noreen Weeden

Pier 94, our habitat restoration site along San Francisco’s southeastern shoreline, is a potential oyster hotbed!

No, we’re not talking about turning Pier 94 into the next Hog Island Oyster Company. These are a different kind of oysters—tiny native oysters that make better eating for wildlife than for humans, and that could become part of our defense against climate change.

Olympia oysters (Ostrea lurida) are an important part of the cultural and natural history of San Francisco Bay. They provide valuable nutrition for birds such as sea ducks and Black Oystercatchers, as well as rock crabs, bat rays, sea otters, and other marine life.

The smallest oysters in the United States (2.4 to 3.1 inches long and 0.9 to 1.3 inches thick), Olympias are the only oyster species native to the West Coast. They were part of the diet of Native Americans and were harvested by Gold Rush newcomers, although today people prefer larger, commercially-farmed Eastern (Atlantic) and Pacific oysters (native to Asia).

Dr. Chela Zabin points out an Olympia oyster / Photo by Noreen Weeden

Olympia oysters, with a shucking knife for size comparison / Photo by Brianhe

Olympia oysters improve water quality and clarity by filtering over five gallons of water per hour while consuming microscopic plants known as phytoplankton. Despite dramatic population declines in San Francisco Bay due to over-harvesting, mining silt, pollution, and habitat loss, remnant populations of our little native oyster have survived.

A fascinating fact about Olympia oysters is that they are sequential hermaphrodites. They start out as males, develop into females, and switch back again, maybe twice in a year. The larvae float in the water and find a place to attach and grow.

All interesting… but what do Olympia oysters have to do with Pier 94?

A shoreline salt marsh restoration site owned by the Port of San Francisco, Pier 94 has been managed by Golden Gate Bird Alliance since 2002. In a 2016 report on vegetation management there, Dr. Peter Baye suggested that native oysters could provide wetland protection and rocky intertidal habitat enhancement.

Aerial view of Pier 94 in 2020 from a kite camera / Photo by Charles Benton

In 2017, we partnered with California Academy of Sciences and others on a bio-blitz at Pier 94 where volunteers documented the presence of our native oyster. Later that year, we invited Dr. Chela Zabin of the Smithsonian Environmental Research Center (SERC), Dr.…

Help enforce California’s rodenticide ban

By Dan Scali

A decade ago, Golden Gate Bird Alliance cosponsored a Don’t Take the Bait campaign that asked San Francisco businesses and residents to voluntarily avoid selling or using the most harmful rodenticides. GGBA then went on to fight rodenticides on a larger scale, alongside other grassroots nonprofits like Raptors Are the Solution (RATS), an advocacy group started by former GGBA staffer Lisa Owens Viani.

Wildlife won a victory in 2014 when California banned all retail sales of second-generation anticoagulant rodenticides (SGARs), the newest and deadliest class of poisons. A year later, the E.P.A. followed suit on a national level.

Red-tailed Hawk carrying a (hopefully unpoisoned) rodent. Photo by Patrick Coughlin.

A rodent bait box with unlabelled contents. Photo by Dan Scali.

A quick refresher: While both first- and second-generation poisons kill non-target wildlife, the latter are stronger and far more dangerous to raptors, other wild predators, pets, and even children. Anticoagulant rodenticides work by causing slow internal bleeding: It can take several days for the poisoned animal to die, during which time it may return for repeat feedings, accumulating even more poison in its body and becoming a super-deadly meal for predators and scavengers.

(For a more in-depth history of the relationship between raptors and rodenticides, check out Cathy Bell’s article in Living Bird magazine.)

The 2014 retail ban was a step in the right direction but in fact did little to reduce secondary poisonings or the accumulation of SGAR toxins in ecosystems. Commercial use by pest control companies was the much bigger problem and needed an additional legislative solution. In September 2020—after years of continued pressure from wildlife advocates—Gov. Gavin Newsom signed into law AB 1788, banning SGARs in California, with certain public health-related exceptions. The new law took effect in January of this year and is a huge victory, but we still have work to do to ensure compliance.

Thankfully, Golden Gate Bird Alliance conservation veteran and all-around rock star Noreen Weeden had our and the raptors’ backs. She brought the new law to the attention of GGBA’s San Francisco Conservation Committee this spring and shared how we can continue to advocate.

Bait stations containing SGARs should be reported to your local Agriculture Commissioner. (Yes, even urban counties like San Francisco have Ag Commissioners.) You can find a list of the prohibited SGARS on the RATS web site. Also report any box that does not label its ingredients, since that is a violation of pesticide regulations.…

Bird education becomes a bird podcast

By Georgia Silvera Seamans

Five years ago, I partnered with Street Lab to design a nature education project called Explore Birds, in which we presented pop-up exhibits of taxidermied birds in historically underserved New York City neighborhoods such as Chinatown.

A program of Washington Square Park Eco Projects, Explore Birds aims to showcase New York’s urban bird diversity using study skins, bio-facts, and other materials. The visitors to our science stations ranged in age and ethno-racial identity. I am a chronic jotter and so always carry a notebook with me. I took quick notes of most of the interactions with participants during one of our Chinatown pop-ups.

The author shares a Red-tailed Hawk specimen with a young girl in Brooklyn, part of Explore Birds with Street Lab. Photo by Street Lab.

“Are they real?” [Many people asked this question.]

Of the red-tailed hawk, a teenager asked, “Is it a falcon? I used to see many in this area but not anymore.”

“This is so cool. I love pigeons.”

“Are they dead?”

“What would happen if a real bird came by?”

“Which has the sharpest beak?”

“Where I play (in New Jersey), there is a hawk that perches and watch us. It shows the environment is better.”

“Would you find these birds in New York?”

Of the red-tailed hawk, “Is it an owl?”

“That’s disgusting!” exclaimed a young girl.

“Are they real? I’m not touching them!” shouted a teen girl.

“Birds are cool,” said a boy.

“Is that a raptor bird?” asked a young girl about the American Kestrel. “I’m guessing that’s another raptor,” as she pointed to the Red-tailed Hawk. I asked her if she studies birds in school. “I love birds a lot,” she said. “I love falcons.”

“I chase it [a pigeon] away every day from [pooping] on my car.”

“Are the birds for sale?” an older man asked in Cantonese.

Of the Tufted Titmouse, a boy asked, “Are these baby birds?”

“I thought they were sleeping.”

The author at a “Move and Walk Weekend” event in New York’s Chinatown, with Explore Birds and Street Lab. Photo by Street Lab.

The curiosity displayed in these questions, statements, and short stories are not unique to New York’s Chinatown. I have installed Explore Birds in other parts of the city, ranging from uptown Manhattan to Brooklyn, Queens, and 2,772-acre Pelham Park in the Bronx. In every location, I’ve been the fortunate recipient of New Yorkers’ bird stories.…

Re-nest Success

By Tara McIntire

I had noticed a persistent Anna’s Hummingbird zipping about our yard, collecting web from all the nooks and crannies, which made me wonder if she were building a nest nearby. Sure enough, a few weeks later our neighbor mentioned there was a very agitated bird in their yard with a nest in their lemon tree. Luckily for me, they lived next door and offered access through the side gate whenever I wished!

I grabbed my camera and headed over to check out the situation. I was delighted to find a female Anna’s Hummingbird tucked inside a perfect nest she had built on a lemon leaf. (Note: The males are absent during parenting, taking no part in nest building or rearing of young.)

Female hummingbird on her beautiful nest – Feb 26, 2021

Still working from home at that point, I was eager to fill rare moments between meetings with something other than more work. I readied my camera and identified the best angles and time of day for lighting, while making sure to not disturb the female who was potentially incubating eggs.

Another view of the nest, built on the leaf of a lemon tree

Anna’s Hummingbird egg incubation takes typically around 16 days, so on March 14th I wandered over to see if there were any changes. With mom safely away, something caught my eye through my long lens. One tiny hummingbird was barely peeking out of the nest!

First view of a hummingbird nestling – March 14

This species of hummingbird fledges roughly 20 days after hatching and since I wasn’t looking directly into the nest, I couldn’t tell how far along the nestling was. However, just six days later I spotted not one but TWO birds, and they were nearly bursting out of the stretchy, tiny nest made of lichens and spider web. I imagined the nest felt a bit like my yoga pants after a long Covid winter eating ice cream and comfort food.

Not one but TWO hummingbirds – March 20

Two days later, our neighbor called and said, “A baby bird fell out of nest!’

“I’ll be right over!” I responded, sprinting to the yard. The nestling was sitting on the concrete patio, from which I quickly scooped it up. My adrenaline valve was wide-open at this point and I went into full emergency-response mode. As I filled a bowl with tissues to make a warm temporary nest, I was also carefully inspecting the bird and visually assessing its general condition.…

Birding by Ear with help from AI

By Margot Bezrutczyk

I’ll probably never know what it was: the bird that sang such complex, liquid song in the thicket of bay laurel that morning on Bolinas Ridge. I tried and failed to come up with a mnemonic, resorting to simile: “It sounds like an Ewok and a robot fighting. It sounds like a computer drowning.” I climbed up some fallen branches hanging off the trail in an attempt to see the bird, but several crows and a wren joined the chorus and began scolding me. I was brand-new to bird identification, armed only with my field guide and binoculars, birding alone during the pandemic, and eventually I simply had to walk away. I found birding in the woods both exhilarating and frustrating, because it was so difficult for a beginner to even know what to listen for.

Then I discovered BirdNET.

BirdNET is a sound ID app developed by the Cornell Lab of Ornithology in partnership with Chemnitz University of Technology in Germany. I’ve been a bit of an evangelist for BirdNET since I started using it, and I was happy to see that similar artificial-intelligence (AI) technology has recently been integrated into the Merlin app as a “Sound ID” feature.

Both apps are free, and both work by recording spectrograms of the sounds detected by your phone. The spectrogram—a visual representation of audio frequency and signal strength or “loudness”—is processed through a neural network that returns one or more predictions based on both the spectrogram and your location. A sound may represent multiple bird species, which the app can identify simultaneously.

You have the option to share your recordings with Cornell’s Macaulay Library, where they’ll be used to improve the quality of IDs in the future. I usually don’t do this because because many of my recordings end with something like, “…it’s just a f*∆king squirrel, again.”

Shortly after downloading BirdNET, I held up my phone towards the cacophony of an oak woodland one April morning, and finally begin to distinguish signal from noise. The first test: I was able to determine that a certain call I’d been hearing for weeks was the song of a Wrentit, an untrustworthy-looking little grey bird I’d seen in my Sibley book and longed to lay eyes on: It was right here all along!

With an idea of what to look for, it wasn’t long before I was able to spot the Wrentit and learn its song by heart.…