Changing Planet

BioBlitz on Alcatraz: Hundreds of Species Logged for Island Gardens

Alcatraz in San Francisco Bay is a part of the the Golden Gate National Recreation Area best known for its birds and the penitentiary from which no successful escape was recorded. But it is also the home of historic gardens rooted in times when the island was first a military base and then a forbidding prison, planted and tended by personnel and their families, often with the help of inmates. Rehabilitated after decades of neglect, the Gardens of Alcatraz are now a tourist attraction — and they were a big source of species observed for the 2014 BioBlitz in Golden Gate National Parks.

Alcatraz Garden Manager Shelagh Fritz was at one stage during last week’s BioBlitz the most prolific uploader of data to the iNaturalist app, the official vehicle for tracking and recording the observation of species across the sprawling parks. We contacted her for some details.

What’s your background and what you do at Alcatraz?

My title at Alcatraz is Garden Manager. I am a horticulturist and I’ve been working to rehabilitate the historic gardens of Alcatraz for the past seven years. I have a Bachelor of Science in Agriculture, specializing in Horticulture and Business from the University of Guelph, in Ontario, Canada. I have had pretty interesting jobs, including a one-year internship at Longwood Gardens in Pennsylvania and caring for the gardens at the Duke of Northumberland’s estate in London. But the Alcatraz gardens are by far the most interesting job I’ve held.

My job includes everything from getting my hands dirty in the gardens, training and working with volunteer gardeners and docents, researching the historic gardens that were once tended by inmates and families of the guards, and then submitting garden plans for approval by the National Park Service. I keep detailed records of the work we have done as previous gardeners did not leave much for us to go on. I also give garden tours, keep our website up to date, and speak at garden clubs.

You were at one stage the most prolific species observer in the BioBlitz. Did it remain that way through the end? Were your reporting only plants on iNaturalist, or were you also recording animals?

I was very surprised to receive a text from an office colleague that I was in the lead by Friday early evening. I know it’s not a contest, but I do like winning! My battery died and then I ran out of daylight. I packed my sleeping bag and slept in the greenhouse so I could stay late and finish up in the morning. I did stop in at the data center on my way home Saturday morning and I was still in the lead by quite a bit. But eventually one other person posted more observations. I was posting only plants.

Tell a little about the gardens on Alcatraz, how they came into being and how they were restored.

The gardens started with the military residents around the 1860s. Soldiers stationed there had their families with them, and the wives naturally wanted to make a home for themselves. When the island became a military prison after the start of the Civil War, the inmates were kept busy gardening and even had vocational training as gardeners. When the military left the island in the early 1930s, the prison guards had their families with them and they tended the gardens. Even maximum security inmates were allowed to garden. Probably most of them were seeking an escape, and in a way, they did find an escape through horticulture.

There are different levels of landscape preservation. The Alcatraz gardens had enough documentation for a rehabilitation, not an exact restoration. Our goal was to create the look and feel of the historic gardens, and to educate the public about the importance of gardening to the island’s residents. We began in 2003 and the first two years were spent removing 40 years of overgrowth from the neglected gardens. We also gathered historic records and photos to piece together the garden story. Staff worked with volunteers to dive into the work, and we have grown since then. Many visitors comment on the gardens being the best part of their trip to Alcatraz, and certainly the most unexpected.


Photograph courtesy of Shelagh Fritz.
Photograph courtesy of Shelagh Fritz.


Watering the garden is a challenge, and especially in the recent drought. How is that accomplished?

Irrigation is always a concern. We knew it didn’t make sense to plant gardens that needed a lot of water on an island that has no source of fresh water. The gardens were designed to be drought-tolerant and we have a catchment system that collects 12,000 gallons of rainwater from the cell house roof. We do the majority of our planting during the rainy season. This year, we have held off on planting until we received more rain. Our catchment is filled to capacity right now, but the soil in the gardens is still dry. In past years, the water would soak down at least one foot; this year, it is still dry four inches down. Most of the gardens will be fine with less water and we will not be planting annuals that need weekly watering this year.

How many native species are in the gardens, and can you give some examples of them?

We only have handful of native species in the gardens, but I’m working to increase this. To list a few: Achillea, Erigeron, Eriogonum, Salvia clevelandii, Rhomneya, Ceonothus, Baccharis, Dudleya, California fuchsia, yellow bush lupine, California poppy, four different ferns, Monterrey cypress, and Rhamnus californica.

What kinds of birds and other animals live on the island?

Alcatraz is a bird haven! We are a major site for seabird nesting. There is the Western gull, Brandt’s cormorant, pigeon guillemots, black oyster catcher, California gull, snowy egret, and oddly, blue heron, Canada goose, plus a mallard duck or two. During the winter there are lots of songbirds and hummingbirds zipping around. I don’t believe the insect life has ever been studied, but there are deer mice, banana slugs and snails.

Is it fair to say that Alcatraz is a haven of biodiversity?

I would say yes. There is so much life on this little 22.5-acre island. Just from the gardens we have plants from every continent except Antarctica. We have such a great climate and even microclimates on the island that we can grow the typical roses and irises, but then we can also grow Fuchsia that are native to the cloud rain forests of central America and succulents from South Africa that thrive in poor soil with no water.

Are there any issues with invasive species?

That’s a tough question. With the gardens being a cultural resource, all of these nonnative plants were brought to the island on purpose. If these same plants were in the habitat areas of the Marin Headlands, for example, they would be invasive. But just as the worst of the worst were sent to Alcatraz, we have our own worst-of-the-worst invasive plants. Cape ivy and Oxalis are constant battles. We have managed the Oxalis in several of the gardens but the ivy is in an area that is closed eight months of the year for the birds to nest, so it is difficult to manage. We don’t use Roundup, but manually weed everything with our crew of volunteers.

How many observations did you contribute to the BioBlitz count, and how many were native?

I had 373 observations and only 10 or so were of the same species. I counted 22 plants native to California.

12418031_10153900711084116_8462971761216697621_nDavid Braun is director of outreach with the digital and social media team illuminating the National Geographic Society’s explorer, science, and education programs.

He edits National Geographic Voices, hosting a global discussion on issues resonating with the Society’s mission and major initiatives. Contributors include grantees and Society partners, as well as universities, foundations, interest groups, and individuals dedicated to a sustainable world. More than 50,000 readers have participated in 10,000 conversations.

Braun also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship

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Forty years in U.S., UK, and South African media gives David Braun global perspective and experience across multiple storytelling platforms. His coverage of science, nature, politics, and technology has been published/broadcast by the BBC, CNN, NPR, AP, UPI, National Geographic, TechWeb, De Telegraaf, Travel World, and Argus South African Newspapers. He has published two books and won several journalism awards. He has 120,000 followers on social media. David Braun edits the National Geographic Society blog, hosting a global discussion on issues resonating with the Society's mission and initiatives. He also directs the Society side of the Fulbright-National Geographic Digital Storytelling Fellowship, awarded to Americans seeking the opportunity to spend nine months abroad, engaging local communities and sharing stories from the field with a global audience. Follow David on Facebook  Twitter  LinkedIn
  • Marko Marrero

    Just to add to the “What kinds of birds and other animals live on the island” question; UC Davis Entomology Club has worked closely with NPS to survey the insects (and other inverts) on Alcatraz in the past with the most recent trip taking place this last January. We work with the Bohart Museum of Entomology at UC Davis to identify and store all of the gathered specimens. This has turned into a somewhat yearly trip as we also help NPS to also run a rat survey and to check for signs powderpost beetles on the island.

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