Blog Posts Archive - Page 5 of 137 - Golden Gate Bird Alliance

Light Pollution on Bird Migration Behavior

By Lydia Bruno

As urban dwellers, we are only too familiar with the effects of light pollution. Rarely can we see stars at night and often we have to travel to remote locations to even glimpse the wondrous Milky Way. Add to that, studies show light pollution can disrupt our circadian rhythms, affecting our ability to get a good night’s rest.

A recent 2023 study published in Nature Communications, Artificial Light at Night is a Top Predictor of Bird Migration Stopover Density (Horton et al.), outlined how light pollution also significantly impacts birds, especially during migration. This is particularly relevant to San Francisco as the Pacific Flyway, a major migratory route, includes the San Francisco Bay Area. An estimated billion birds travel through this flyway during spring and fall migratory seasons. The majority of these migrants are songbirds and they take flight primarily at night. Skyglow, or the artificial brightening of the night sky by light pollution, affects their nighttime migration by increasing stopover.

What is stopover? Like it sounds, stopover is the act of stopping over a place, essentially a rest stop along the birds’ epic journey, a pause to refuel, rest or take refuge from adverse weather conditions. This is an important and necessary part of their journey. However, due to habitat changes, with many areas becoming drier, less forested and brighter at night, historic stopover locations are at risk.

Along the Pacific Flyway, skyglow was found to be the top driver of stopover in an area. While this may at first seem positive, there are in fact, negative consequences depending on where the stopover occurs. Urban areas, like San Francisco, generate more skyglow than less populated areas and can become ecological traps, luring birds to areas where they are at greater risk of colliding with buildings,predation, and potentially throwing them off course, disconnecting them from their migratory path..

The next step for researchers is to determine whether stopover hotspots are truly important ecological locations, the effect of skyglow luring the birds to the area or a combination of both.

What we do know is, with light pollution increasing at a disconcerting 10% per year in North America, we need to invest in advocacy, collaboration and policy change to decrease this trend and reduce skyglow.

How can you help? There are simple actions we can all take, including turning off unnecessary indoor and outdoor lights at night, closing blinds/curtains after dark, using warm colored LED bulbs (as bluer colored light has larger reach and worsens skyglow) and using dimmers and timers to minimize light usage.…

Birdathon 2024 – Our Most Successful Fundraiser Ever

By Sharol Nelson-Embry, Birdathon 2024 co-chair

Over the last couple of months, we held our largest annual fundraiser, Birdathon, to fund our education programs, advocacy work, and conservation of bird and wildlife habitats year after year. It was the most successful fundraiser we’ve ever held, raising upwards of $160,000. The best part was the fun had by the organizing committee as well as roughly 400 members of our community who participated in the nearly 50 programs offered as part of the fundraising.

The month of April, along with a couple of weeks before and after, was devoted to offering nearly 40 field trips led by our own volunteers and some special guest leaders. GGBA Board President Chris Tarr, and Board Treasurer Derek Heins led that effort. Chris and Derek’s familiarity with expert leaders and birding hotspots helped them put together a rich offering of trips throughout San Francisco and Alameda County as well as trips further afield. With nearly double the number of trips we’ve offered in the past, we exceeded our goal by raising $65,000. We had 278 people participate in the tours in total.

Bird Photographers by Rick Lewis

Bonaparte’s Gull by Nico Stuurman

Birding by Boat by Jeff Manker

At the tail-end of our Birdathon we hosted an Adventure Auction led by Daryl Goldman with help from Ilana DeBare, Patrick Meeker, and Mary Wand. Exciting auction items included “Bed and Bird” lodging packages, including a trip to Central Park in New York and a trip to the Rocky Mountains. Other “Bed and Bird” packages featured local options in Lodi, San Francisco, and further afield options, with three offered in Arizona and some on the north coast of California. We also had local adventure outings around the Bay Area such as a coffee tasting, a package of museum memberships, a guided history tour of Oakland by bicycle, and many others, all donated by generous members and businesses. This was GGBA’s best auction ever, raising over $23,000.

Sandhill Cranes in Lodi by Rick Lewis

Our Bay Birding Challenge this year featured not just two but SEVEN teams competing to see who could find the most bird species in a day as well as raise the most money. Whitney Grover, our Deputy Director, coordinated the effort. Imagine a day starting at dawn and filled with the excitement of moving from birding hotspot to hotspot until dark, trying to be the winning team.…

The Prelinger library

By Chris Tarr

An unusual field trip offered in this year’s Birdathon is a visit to the Prelinger Library. Do not miss the chance to see this amazing local hidden gem!

I first learned about the Prelinger Library when I was in the Master Birder program with Megan Prelinger. I’m a retired librarian myself, and the first thing I marveled at was the organization of the material. The library does not follow Dewey Decimal or the Library of Congress classification system, but instead is organized in a way that suited the needs of its first users, Megan and Rick. It uses a “landscape-based, geospatial arrangement system” starting in San Francisco and ending in outer space. It moves from landscape and nature through artiface (art, media, and culture), abstraction (society and philosophy) to space exploration.” Here is an overview of the arrangement, or read Megan’s explanation of the arrangement here. If you have a home library, it’s like what would happen if you had the time and space to arrange all of your materials in the way that made the most sense to you. In browsing a library collection, it’s often the materials next to the thing you are looking for that prove to be the most interesting. The arrangement itself, of course, is as revelatory as anything written with the materials contained.

The second amazing thing about the collection is the materials. In an SF Chronicle article written in 2015, Rick says, “We were not so interested in ordinary books that you would see at a public library. We were interested in books that were evidence in a lot of ways, books that had illustrations, books that had underrepresented or suppressed narratives in them.” “Books,” Megan says, “that expressed moments in history rather than told stories about moments in history.” Included in the library are materials they’ve used for research projects of their own, deaccessioned library materials found on cross country collecting trips including a complete run of the Auk, a collection of New York State forestry documents which include lithographs of every lake in the Adirondacks, all kinds of ephemera. If the idea of the arrangement is serendipity, it’s the depth and uniqueness of the collection that makes that possible. Check out this Stack Explorer to see a few examples of what’s on the shelves.

The library was started in 2004, when Rick and Megan pooled their books and records and realized that renting a space for a library would be cheaper than renting storage space.…

Six Common Mistakes in Native Gardening

By Amy Chong

Native plant gardens are a fantastic way to attract birds and pollinators to your yard — but they’re quite different from other forms of gardening you may have done in the past. Here are six common mistakes that I’ve seen beginner native gardeners make. With a little forethought and planning, you can avoid these pitfalls and create a healthy, vibrant backyard for both you and wildlife.

A native plant garden designed to attract birds and pollinators in the East Bay. Photo was taken three months after planting, leaving enough space for each to grow. Photo by Brandon Morgan.

1. Planting too close to the house.

Knowing the mature size of each species before you plant it in your yard is important to give it enough space to grow into a healthy plant. Trees like Toyon (Heteromeles arbutifolia), which produce winter berries for birds like thrushes, thrashers, and Cedar Waxwings, can reach a mature height of 30 feet. Avoid the common mistake of planting a large plant just a few feet from the house, thinking you’ll prune it back each year. Large roots can potentially damage house foundations, and moisture from irrigating the plant can cause water damage. Do what’s healthiest for the plant and for your home—plan ahead and only plant a species that you have enough space for.

This large shrub (a non-native camellia) was planted right next to the house and will need to be pruned regularly. Large plant roots can impact foundations. Photo by Amy Chong.

2. Planting too far apart.

Are you captivated by the mid-century modern look? Landscaping with modern minimalist design leaves a lot of open space between individual plants. In the wild, however, most plants don’t grow like that. Plants generally grow best when they are in close proximity to each other, as covering the soil prevents desiccation, promotes mycelial networks, and encourages healthy invertebrate life. Plants spaced far apart—even with mulch or gravel covering the ground—have to struggle more to make it on their own. Give your natives friends: know how large they will be when mature and space them appropriately near others, with vertical layers of ground cover, small perennials, larger shrubs, and trees.

These native plants are spaced well, with strawberry as ground cover, different small flowering perennials, and a small tree—manzanita—arching over in the back. Photo by Amy Chong.

3. Focusing solely on flowers and fruit.…

Birding the Bay Islands: Mare Island Shoreline & Beyond

By Helen J. Doyle and Evan Weissman

Maybe the birds knew Valentine’s Day was just two days away. Love was in the air, literally. Soon after we left the Mare Island San Pablo Bay Trail parking lot, we were stopped in our tracks by two pairs of Northern Harriers in full airborne courtship display, swooping around each other, showing off their legs and feet, and vocalizing back and forth.

Northern Harriers were also using the sky for stunning displays of romance. Both species are year-round Bay Area residents, feeding on small mammals and birds that also thrive in this marshy, grassland habitat. A thrilling start to birding on Mare Island.

Northern Harriers displayed mating behavior and hunted over the grassland habitat, Helen Doyle

First though, is Mare Island really an island? Its Spanish names suggest it was at one time – Isla de la Plana (Flat Island) around 1775 and later, around 1834, Isla de la Yegua (Mare Island), renamed by Mariano Guadeloupe Vallejo in honor of his white mare who safely swam ashore here after a boat capsized in the Bay in 1835. Soon after that, in 1854, the US Navy opened its first west coast shipyard here. The Navy and shipbuilding dominated Mare Island for almost 150 years, until 1996, changing its landscape to better suit these industrial purposes. Now Mare Island is a peninsula, bordered by the Napa River and the San Pablo Bay, but it’s easy to imagine that the Napa River once flowed more freely into the Bay, creating wetlands dotted with islands like Mare Island. Today those wetlands make up the San Pablo Bay National Wildlife Refuge. Mare Island is not technically part of this refuge, but its wetlands are also being restored as the decades-long decommissioning of the Mare Island Naval Shipyard continues.

To get here, we ferried from San Francisco to Vallejo with our bikes and rode over to Mare Island via the scrappy but solid Mare Island Causeway Bridge, built in 1934. We sited a few morning birds along the Vallejo marina and shoreline park before meeting fellow-birders Jon Altemus and Marilyn Nasatir at the San Pablo Bay Trail parking lot. Despite a reputation for single-mindedness, birders are generous about sharing knowledge and teaching others. We laughed about Marilyn’s story of becoming hooked by birds over three decades ago. After a bird walk in Golden Gate Park, for which she had opera glasses but no binoculars, she thought she’d seen just three types of birds.…