Editor’s Note: The U.S. Fish & Wildlife Service is considering using rodenticides to eliminate non-native mice from the Farallon Islands. While Golden Gate Bird Alliance generally opposes the use of rodenticides, we are supporting the use in this case because it is the only way to protect the native species of the Farallones. This post is reprinted from the newsletter of Marin Audubon, which also supports the mouse eradication campaign.

In August, the U.S. Fish and Wildlife Service released its draft Environmental Impact Statement (DEIS) on eradicating introduced house mice on the South Farallon Islands. MAS supports eradication of the non-native house mice to restore the ecosystem of the Farallones. If action is not taken to rid the island of mice soon, all of the Ashy Storm-Petrels and probably Leach’s Storm-Petrels could be lost.

The Farallon Islands National Wildlife Refuge, 30 miles outside of the Golden Gate, is a seabird breeding habitat of worldwide significance. The Refuge comprises the largest nesting seabird colony in the contiguous U.S. outside of Alaska, including half of the Ashy Storm-Petrels in the world and the world’s largest breeding populations of Brandt’s Cormorants and Western Gulls. Removing non-native mice would restore the island’s ecosystem for native species. The primary beneficiaries would be Ashy and Leach’s Storm-Petrels.

Ashy Storm-Petrel and Farallon Islands / Courtesy of US FWS

House mice originated in Asia and were brought to the islands, along with cats and rabbits, via ships during egg gathering and during lighthouse and military operations in the early 1900s. The cats and rabbits were removed in the 1970s, leaving the house mice as the only non-native mammals. Mice are omnivorous. On the island they eat the Maritime goldfield (a plant), the endemic Farallon camel cricket, and the Farallon arboreal salamander, reducing the populations of these native species and further disrupting the island ecosystem. Scientists have also found evidence of mice preying on petrels (missing toes and legs).

Farallon arboreal salamander / Photo from Point Blue's Los Farallones blog

In spring on the South Farallones, house mice can reach plague-like densities of 490 mice per acre, among the highest found on any island in the world. Scientists have observed that it can appear as though the ground itself is moving.

Burrowing Owls are among 400 different land bird species recorded on the islands since 1968, when PRBO/Point Blue began to study birds on the islands. Most of the owls stop to rest and depart within a few days.…

By Frances Dupont

The Burrowing Owls are back!

And this year, Golden Gate Bird Alliance is expanding its Burrowing Owl docent program beyond Berkeley to cover a 30-mile stretch of the East Bay – from Point Pinole to Hayward.

Over 30 enthusiastic volunteers attended the annual Burrowing Owl Docent Training Workshop at the Shorebird Nature Center in the Berkeley Marina on Sept. 28.  GGBA now has twenty new docents and 19 experienced docents to cover the expanded area during the 2013-2014 season.

The first owl of the season was officially spotted the day after the workshop by our youngest docent ever – a nine-year-old bird lover who had just been through our training!

The owl showed up within the boundaries of the art installation at the northeast corner of Cesar Chavez Park, where owls have now been observed for up to 10 years.  The area includes protective walls and fencing that discourage dogs and people from disturbing the owl, and signs that talk about the Burrowing Owls and other wildlife that inhabit this former dump site.

First Burrowing Owl to arrive at Chavez Park in fall 2013 / Photo by Lyell Nesbitt

Golden Gate Bird Alliance docents visit this area regularly to help people find and observe the well-camouflaged little owls, using binoculars, scopes, or cameras with large lenses. Docents answer questions about the owls and offer suggestions about how to protect them, including gentle reminders about the importance of keeping dogs on leash along the shoreline trails.

Frances Dupont speaks to Burrowing Owl docents at the annual training / Photo by Della Dash

The Burrowing Owls come to Chavez Park around the 1^st of October after a busy summer raising families somewhere farther north.  One banded owl was found to have come from Idaho.  A recent study of Burrowing Owls in Washington state concluded that it is mainly the females who come as far south as California, while most of the males stay closer to home.

Because Burrowing Owls are found all along the East Bay shoreline, the GGBA Burrowing Owl program is expanding its scope by attempting to locate and document as many as possible of the shoreline owls between Point Pinole and Hayward.  This will be a tough task, considering how well hidden they can be, and that some of the sites where they might be hiding out are inaccessible.

Burrowing Owl in January 2013 by Doug Donaldson First Burrowing Owl of the 2013-14 season / Photo by Doug Donaldson Burrowing Owl in December 2012 by Doug Donaldson

We know that the owls come to Chavez Park in Berkeley, Martin Luther King Jr.…

By Ilana DeBare

Good news for California Condors, Golden Eagles and other raptors — Gov. Jerry Brown has signed AB 711, the Audubon-backed bill that will ban lead ammunition in hunting!

In his signing message released on Friday, Brown said:

“The risks to California’s incredibly diverse wildlife are many. We must manage our state’s wildlife for the use and enjoyment of all Californians. It is time to begin this transition and provide hunters with ammunition that will allow them to continue the conservation heritage of Califorina.”

Lead ammunition is a significant source of mortality for condors and other predators that eat carcasses or prey contaminated by fragments of lead bullets. Elevated levels of lead have also been documented in people who eat wild game.

Audubon and other conservation and health organizations made AB 711 a priority for the 2013 legislative session. But it was strongly opposed by the gun lobby. In a letter to the governor, a group of Republican legislators charged that AB 711 would “effectively destroy a vital component of rural life in California.”

AB 711 will take effect in 2019, providing plenty of time for hunters to switch to other forms of ammunition. Meanwhile, Audubon California Executive Director Bridget McCormick said that Audubon “will work closely with the State Fish and Game Commission to ensure that the new rules are implemented properly.”

Gov. Brown did not sign all of the gun-related bills that were sent to him by the Legislature this year. For instance, he vetoed a bill to classify all semi-automatic rifles with detachable magazines as illegal assault weapons, as well as an effort to let Oakland draft its own, stricter gun regulations.

Why did he approve AB 711? Certainly it’s an important bill for wildlife and public health.

But the governor may also have felt the pressure of thousands of Audubon members who wrote and sent emails in support of AB 711.

Did you speak out in support of this measure? THANK YOU for helping make it a reality!

Golden Eagle / Photo by Joe DiDonato

 

And while we’re on the topic of raptors… join us this coming Thursday October 17 for a presentation in San Francisco by Doug Bell on Golden Eagles of the East Bay.

The East Bay harbors one of the densest nesting populations of Golden Eagles in the world. Yet development is squeezing eagle habitat, and the Altamont Pass wind farms continue to kill eagles at an unsustainable rate.…

By Ilana DeBare

It’s the time of year when some old, out-of-use chimneys at a San Rafael brickyard become a site of avian wonder.

Tens of thousands of Vaux’s Swifts migrate south through California each fall, stopping to sleep overnight in brick chimneys, a modern version of their traditional hollow-tree roost. There are only a couple of places where the swifts are known to stop, and these sites draw up to thousands — sometimes as many as 19,000 — birds on a single night.

One of their roosting sites is the McNear Brickyard in San Rafael, discovered in 2010 by Golden Gate Bird Alliance field trip leader and birding instructor Rusty Scalf.

Rusty continues to visit the brickyards several times each week, counting the number of swifts for a citizen-science tracking effort led by Washington state biologist Larry Schwitters.

This year’s numbers in San Rafael have been generally lower than last year. Since this year’s initial sighting on September 18, they’ve ranged from 855 to 4,000. Last fall, by comparison, the low was about 3,500 and the high was over 19,000.

McNear Brickyard in San Rafael, before dusk. The swifts prefer the chimney on the left. / Photo by Ilana DeBare

I went out with Rusty on Wednesday and we counted just over 1,200. That sounds meager in comparison to last year, but it was still an amazing sight.

We waited. And waited. Saw some quail, bluebirds, House Finches, but no swifts. We waited some more, almost ready to give up. Were the swifts done with their migration already?

And then at 6:27 p.m. we saw a few, swooping near the chimney top. And then some more. And then suddenly it was a swarm, a blanket of black dots, looping and twirling in the wind.

Swifts start to arrive / Photo by Ilana DeBare Swifts in San Rafael / Photo by Ilana DeBare

The swifts flirt with the chimney. They circle broadly around it, as if toying with the idea of entering, and then swirl away out of sight with a gust of wind. They return and circle, and again swirl away. They could be a blizzard of dark snowflakes. They are like dancers doing some wild, fluid choreography in the wind. They are like children having too much fun to go to bed.

Finally some start popping into the chimney — one, two, ten, twenty, fifty. Hundreds continue swirling around, dozens are entering.…

By Burr Heneman and Janet Visick

We did our first high country trip in a long time in early August, and we took three of the best possible companions along with us: Ted Beedy, Ed Pandolfino, and Keith Hansen. They accompanied us in the form of their entertaining, informative, and beautifully illustrated and produced new Birds of the Sierra Nevada – Their Natural History, Status, and Distribution.* Thus armed, we set off in search of the elusive Gray-crowned Rosy-finch.

Let’s get out of the way what this book is not. If you have a copy of Discovering Sierra Birds** and know that Birds of the Sierra Nevada started out as a revision of the earlier book, you should forget there is any connection. This is an entirely new work with new and expanded information covering more species and a greater geographical area. The Introduction explains its “stronger focus on status, distribution, and conservation of Sierra birds.”

Birds of the Sierra Nevada

And it is graced by Keith Hansen’s illustrations of each of the 276 species that occur most regularly in the Sierra Nevada. (In his preface to the book, Rich Stallcup said of Keith’s artwork, “the precision of every detail is simply amazing. How does he do that?”)

Birds of the Sierra Nevada is not a field guide. If you’re not interested in the mass of behavioral, status, and habitat information in Birds of the Sierra Nevada, just stick with your Sibley guide or whatever you use. If you’re like us, you won’t lug this book into the field. It’s for enjoying in the car on your way to and from the high country, and in the evening as you recover from a day’s exploration at higher elevations than you may be used to.

Three features — the species accounts (310 of the book’s 430 pages), the strong chapter on ecological zones of the Sierra, and the unique chapter on population trends of many species over the past 40 years — make it an excellent resource on the Sierra Nevada avifauna.

The chapter on Ecological Zones and Bird Habitats is more informative than most such chapters in natural history guides. Example: it has long been known that blue oaks are not regenerating well in the oak savannas of the Sierra foothills, and grazing has received the blame. But did you know that recent research shows competition with non-native weed species may be as important, and that simply removing cattle can make that problem even worse?…