• Butterflies on Mount Sutro in 2020

    Editor’s Note: Liam O’Brien started conducting twice-monthly butterfly surveys on Mount Sutro in 2020 as part of our wildlife monitoring for U.C.S.F.’s new Vegetation Management Plan, which was the subject of our previous blog post.

    By Liam O’Brien

    Saturday, February 13, 2021 was a glorious day. The sun was perfect, the Castro was full of people on the streets (like the old, pre-Covid days ) and low wind cemented in my mind that I needed to visit the summit of Mount Sutro.

    After an arduous hike up, I entered old Nike Road through the dappled sunlight of the eucalyptus forest. It was too early for the Western Tiger butterflies I’d seen here last year. But there dancing above the nasturtiums was a lone Cabbage White (Piers rapae)—a full month earlier than the first one I’d seen here in 2020.

    Cabbage White butterflyCabbage White butterfly / Wikipedia

    There is an annual contest held by the great butterfly professor Arthur Shapiro in Davis, California. He buys a beer for any of his students who can catch and verify the first Cabbage White of the season. A few days before my Mount Sutro visit, the first one of 2021 had been caught outside Sacramento city limits. This San Francisco sighting was my first butterfly of the new year. Folks dismiss the Cabbage White as one of those “rat” species and a rather generic butterfly. But I think it’s the perfect species to pause on in this write-up on before the flashier ones start to show up in springtime.

    I’m going to now shift things to reviewing my 2020 surveys, gleaned from the annual report I turned into Golden Gate Bird Alliance in January.

    It’s been wonderful to return to this little Eden month after month. I’ve gotten to watch the seasonality change, with different types of birds and bees passing through and the flowers—so incredibly important to butterflies—going through their life cycles.  Ultimately 2020 revealed 20 species of butterflies that dropped into the summit of Sutro over the course of the year.

    When I created the Butterflies of San Francisco pamphlet in 2010 for Nature in the City, I concluded that we had approximately 34 breeding species within our county. This would give Mount Sutro a little less than 2/3 of the known species in town.

    The summit of Sutro has a couple of things going for it when it comes to butterfly presence. …

  • Birds and Mount Sutro’s changing forest

    By Whitney Grover

    “Trees, trees, beautiful trees,” the high-pitched song of the Brown Creeper rings out from a nearby tree trunk. These well-camouflaged little birds creep up the trees, hunting insects in the bark. Brown Creepers don’t breed on San Francisco’s Mount Sutro but they often come around to forage in the spring and fall. I imagine they wish they could change their tune to something less enthusiastic when they come to this hill we call a mountain.

    For Brown Creepers, the eucalyptus that dominates the mountain is not their cup of tea. There are far more insects and spiders on the mature old oaks in Golden Gate Park or the big redwoods sprinkled through our parks. On one of my visits to Mount Sutro, a Brown Creeper was navigating the corrugated sides of a shipping container in a parking lot, giving up on the surrounding trees for some easy pickings of spiders.

    Brown CreeperBrown Creeper by Bob Lewis

    Birds adapt. Many of the traits we find beautiful about birds are also the things that make them able to fill new niches and adapt to strange new environments: flight, charisma, and intelligence. And Mount Sutro is a striking example of a new, transformed environment.

    In the late 1880s Adolf Sutro developed the grassland and dune landscape of San Francisco by densely planting some of it with eucalyptus and cypress, with the intention of harvesting it for lumber. Much of it was harvested and later developed, but certain areas like Mount Sutro were left with this tightly packed foreign forest. The now-61 acres were designated an Open Space Reserve by its current owner, U.C. San Francisco, in 1976.

    Despite the main forest being non-native, other native understory plants like ferns, elderberry, and poison oak thrive. And because of decades of hard work by groups like the Sutro Stewards and the Rotary Club, the summit area in particular is a paradise full of the native plant species our local birds love.

    Native plants in the Rotary Meadow on Mount Sutro,Native wildflowers in the Rotary Meadow on Mount Sutro, by Ildiko Polony Volunteers planting at Mount Sutro's Rotary MeadowSutro Stewards volunteers planting at Rotary Meadow, by Kelly Dodge

    In 2018 a new chapter began for the Mount Sutro Open Space Reserve. After many years of planning, UCSF published a 20-year Vegetation Management Plan. Work began by removing the dead and dying trees in target areas of the mountain. UCSF contracted Golden Gate Bird Alliance to perform a bird survey to monitor the impact of the work on bird populations, and starting in 2020, Lepidoptera (butterflies and moths) were added to the survey.…

  • Top Guns of Bay Area Birding, 2020

    By Michael Stevens

    Quite a story unfolded on the eBird Top 100 lists for 2020. After many years with the same excellent birders at the top of the heap, newcomers emerged as Champion Birder of the Year in both San Francisco and Alameda Counties. It seemed remarkable because of the combination it takes to get that sort of lofty year list—time, commitment, skill, and experience. How would not one but two rookies emerge who could compete at that level? The short answer is the obvious one: Both Rachel Lawrence and Alex Henry are fine birders who arrived in the Bay Area, separately, toward the end of 2019.

    Rachel, the top San Francisco eBirder, was a parasite immunologist and faculty member at the Royal Veterinary College of The University of London who decided to convert a long-distance relationship to a marriage. When the wedding bells finished chiming, she found herself living in Bernal Heights.

    Alex, the top Alameda County eBirder, was a recent University of Michigan graduate who achieved the fondest wish of pretty much every recent grad when he landed a job in the East Bay and a place to crash in Berkeley.

    [Editor’s Note: Alex will be presenting a Birdathon Virtual Field Trip on “Finding Rarities in the East Bay” on Wednesday evening, April 21st. Click here for details and sign-up for this Zoom event.]

    Let’s hear directly from these two.

    Rachel Lawrence and Alex HenryRachel Lawrence and Alex Henry. Photo by Michael Stevens

    Q: How about a quick origin story – how did you become a birder?

    Alex: That’s easy – I was an eight-year-old living outside of Boston when a pair of Broad-winged Hawks built a nest in some nearby woods. Suddenly there were rodent and songbird scraps all over the neighborhood and I was fascinated. My parents really were supportive and pretty soon I was traveling all over Massachusetts looking at birds.

    Rachel: I grew up in Dorset on the south coast of England with parents who were sailors, so we were outdoors with binoculars a lot. I have a story like Alex’s – we were a couple of miles offshore when a Peregrine Falcon exploded onto a Black-headed Gull. It took a few moments to settle it in and then turned around and just headed for shore!

    Q: Nice, very “circle of life!” Speaking of apex predators… it’s the end of 2019 and you’re new in town. At what point did you realize you were going to totally go nuts in 2020?…

  • Osprey Cam launches fifth nesting season

    By Craig Griffeath

    A little over seventy-five years ago, a visitor to the naval shipyards at Richmond’s Point Potrero would have encountered an impressive bustle of activity, with thousands of tough, dedicated “Rosie the Riveters” putting in long days on the heavy equipment at the yard in order to provide for their families. Today, at the historic Naval Shipyard No. 3, you can still see the last of the huge Whirley Cranes that once built the WWII Victory Ships there. And there’s still one tough, smart, dedicated Rosie there too, working hard atop the crane to raise her children. She’s an Osprey, and she’s also an Internet star whose fans are at the forefront of research into San Francisco Bay’s Osprey population.

    Rosie on Whirley CraneRosie on the Whirley Crane last year, in March 2020

    Just a few weeks ago, on February 18, Rosie completed her annual migration and returned to the Point Potrero Whirley Crane to reunite with her endearingly quirky mate Richmond, an event greeted with jubilation by the thousands of fans who follow the couple’s adventures on the Golden Gate Bird Alliance Osprey Cam at sfbayospreys.org. Fierce and charismatic in equal measure, Rosie and Richmond now command their own Facebook page, their own YouTube channel, and a remarkable network of volunteers and supporters who make up their broader human family.

    Richmond is one of just a few Ospreys around the Bay who don’t migrate in the fall. Instead he stays close to his namesake town for carefree winters of fishing on the Bay, paying occasional visits to the nest site while awaiting his mate’s return. This year’s reunion marked the start of Rosie and Richmond’s fifth season of nesting together at the Whirley Crane. The pair have fledged ten chicks since 2017, all banded for identification, and at least two of those banded offspring have been seen around the Bay after their own first return migrations.
    Rosie and RichmondRosie (left) and Richmond, together again, on March 4, 2021. You can identify Rosie by her speckled “necklace.”
    Rosie and RichmondRichmond with his wings up and Rosie on the cable, March 13, 2021

    Rosie and Richmond’s success is emblematic of the larger success their species has enjoyed in recent decades. Among the most widely distributed of all bird species, Ospreys are voracious fishers who historically built their nests in the tops of trees next to water. In the 20th century, Ospreys faced existential threats from habitat reduction and pesticides such as DDT, but they’ve made a strong global recovery since the 1980s.

    …

  • Sage-Grouse Courtship Season

    Editor’s note: On Wednesday, March 24, Bruce Mast will be leading a Virtual Field Trip via Zoom to see Greater Sage-Grouse courtship dances, as well as Sage Thrasher and Sagebrush Sparrow—a Sage Trifecta. As a preview, we’re reprinting Bruce’s 2019 blog post about his annual Sage-Grouse trip to Lassen County. You’re invited to join us for his March 24th Zoom presentation, which is part of our annual Birdathon fundraising month: Details and registration at goldengatebirdalliance.org/birdathon_trips/43301/.

    By Bruce Mast

    The eastern sky was just beginning to glow pink. We were cold. It was early spring in the eastern Sierras and we were cold. And under-caffeinated. We had been up since 4 a.m., bundling into our down and fleece, driving since 5 a.m. past the High Desert State Prison, and then trudging up the flank of Shaffer Mountain to shiver expectantly on the side of a rutted jeep road. We were 20 hardy souls from Golden Gate Bird Alliance, under the veteran leadership of Dave Quady. Why had we journeyed northeast to Susanville to visit such a desolate place? The answer came soon enough.

    Grouse watching at Shaffer Lek

    The answer came quietly—low, muffled plopping sounds from the north. A binocular scan revealed an expanse of yellow, lava-strewn grass interrupting the sagebrush sea. But some of the rocks were moving! As morning light spread over the landscape, the tableau came into focus. Greater Sage-Grouse, those enigmatic denizens of Basin and Range sagebrush country, were gathering for their annual lekking ritual. Wikipedia tells us that a lek is an aggregation of male animals gathered to engage in competitive displays to entice visiting females, which are surveying prospective mates. The term derives from the Swedish “lek”, a noun that typically translates as “play”. The term was originally used for Black Grouse (Swedish: “orrlek”) and for Western Capercaillie (Swedish: “tjäderlek”).

    Sage Grouse, Shaffer Lek, Lassen Co., March 19, 2016

    On this morning, multiple male Sage-Grouse strutted regally, their spiky tails fanned, white feathering on the sides and back of their necks forming a royal ruff. Large air sacs on their breasts suggested avian bagpipes. Scope views revealed large yellow bare patches on their breasts, a yellow fleshy comb above the eye, and wispy filoplumes extending from their nape.

    The dominant males held court in the center of the lek, challenging newcomers for status and position. Most interactions involved choreographed strutting and posturing but occasionally a wing fight was required to put a young male in his place.…