By Jack Dumbacher

We know that birds have been adapting to life in human landscapes. They change their songs to stand out against the urban background din,  they sing at times of day when they are more likely to be heard over our noise, and several recent studies have shown that they have been adapting to avoid traffic hazards.

Some 80 million birds are estimated to die each year on American roads, and two groups of avian biologists took observations from their daily commute to learn about how birds are adjusting.

Charles Brown has studied Cliff Swallows for many years in Nebraska.  Although the birds typically nest in mud banks and cliffs, they have taken to nesting in highway bridges and overpasses.  While this creates excellent nesting habitat, it may not be the safest place for flying.

For years, Brown collected dead swallows from the roadside and prepared these specimens for the local museum. Over the years, he noticed that Cliff Swallow road kill numbers were declining, but he was unable to find a correlation with their population sizes or the numbers nesting near roads.

Careful measurements showed that birds with longer wings (and therefore less agile) were more likely to be struck and killed by cars – and that overall, this natural selection was causing wing length to become shorter in this population of swallows.  Thus, he was able to show that auto traffic was killing the less agile swallows and selecting for more agile, shorter-winged swallows! [1]

Another study, just out, suggests that birds actually can tell the speed limit on local stretches of road. [2]

Pierre Lagagneux had a long commute through towns and countryside in his little Peugeot. To pass the time, he started measuring the distance from him that birds initiated their flight as he was approaching (his so-called Flight Initiation Distance, or FID).  This was easy to do, by simply multiplying his speed by the time it took to reach the place where the bird flew.  By measuring hundreds of birds in lots of different places, he was able to show that birds had longer FIDs in faster speed zones, and they had shorter FIDs in slow zone – regardless of the speed that the approaching car was going.

Thus, they were not estimating the speed of the particular oncoming car; rather, they formulated some estimate of the local speed limit.  …

By Ilana DeBare

There’s some potentially good news for the Cliff Swallows near the Highway 101 overpass in Petaluma: Caltrans may reevaluate the use of netting that has trapped and killed more than one hundred birds at that bridge.

Faced with an ongoing lawsuit by conservation groups including Golden Gate Bird Alliance, Caltrans in July asked for information about the netting’s impact on swallows and whether it is significant enough to require a more complete environmental assessment than was initially done.

“Caltrans now has a chance to get this project right, and should immediately supplement the environmental review so bird protection measures can be evaluated and in place before swallow nesting season,” said Veronica Bowers of Native Songbird Care and Conservation, the Sonoma County group that raised the initial alarm over the deadly netting. “Disturbing the nesting colony and killing swallows again this spring is not an option.”

The Petaluma overpass problem started last spring, when Caltrans began widening Highway 101. The overpass has long been a nesting destination for Cliff Swallows who have made the thousand-mile flight up from wintering grounds in South America.

The Migratory Bird Treaty Act prohibits disturbance of nests. So to prevent the swallows from nesting in the construction area, Caltrans installed netting on the bridge. Exclusion of nesting birds is often standard procedure for construction projects, but the Petaluma nets were sloppily installed and turned out to be a death trap — entangling, maiming and killing scores of birds.

Despite numerous protests by wildlife lovers, Caltrans refused to remove the nets and consider alternative, safer ways to prevent the swallows from nesting there. So in May, the Animal Legal Defense Fund, Center for Biological Diversity, Madrone Audubon, Marin Audubon, GGBA and Native Songbird Care filed suit to halt the killing.

The judge turned down our initial request for an injunction to stop the project. But now nesting season is over for the year. Caltrans has a window of several months to reevaluate this ill-starred strategy and come up with a better approach.

Will they do so? We’re keeping our fingers crossed — and the legal pressure on.

“There are some common-sense solutions Caltrans should evaluate, such as scheduling bridge construction work outside of nesting season, or (safer) methods to encourage swallows to nest elsewhere during construction,” said Susan Kirks with the Madrone Audubon Society.…

By Sam Zuckerman

In the vast array of birding guides, it’s hard to stick out. Harry Fuller’s Freeway Birding: San Francisco to Seattle (Living Gold Press, 2013) distinguishes itself with a special hook. It only covers places to bird along the 800-mile Interstate 80 and I-5 corridor from San Francisco to Seattle. If a birding spot can’t be reached by taking a detour of 20 minutes or less, it’s not in the book.

Think of it as On the Road meets National Geographic Guide to Birding Hot Spots.

That’s precisely the book’s great virtue and weakness. The San Francisco-to-Seattle freeway route is certainly a rich birding area. As Fuller notes, fifteen National Wildlife Refuge units lie near the road, many of them wintering grounds for scores of migratory waterfowl species. Obviously though, some of the most spectacular birding destinations are outside the book’s geographical limit, including those along the Pacific coast and in the Sierra Nevada and Cascade Mountains.

Within the limits he’s set for himself, Fuller — a former Golden Gate Bird Alliance field trip leader who now lives in Oregon — does a workmanlike job of cataloging birding sites. He provides generally accurate information about refuges and parks, including driving directions for reaching them, what facilities are on site, what habitats are there, and a few of the species that can typically be found.

For some of the more important areas, such as the Sacramento National Wildlife Refuge, the descriptions are lengthy and detailed.  In addition to sites that have been formally set aside as parks and protected areas, Fuller describes opportunities for birding at a few rest stops and side roads along the freeway.

Freeway Birding includes more than 100 maps of individual birding locales or the regions I-5 passes through. Although the book is not a field guide, it includes brief descriptions of a small number of species, including the Calliope Hummingbird, Wrentit, and Northern Spotted Owl. The book has some nice drawings, but no photos.

I have family in Seattle, and I travel there often. Generally I fly to Seattle so my I-5 birding experience has been limited to some of the California refuges north of Sacramento. I judged Freeway Birding by its descriptions of places I’m familiar with.…

By Ilana DeBare

It’s that time again — fall migration!

Hawks, shorebirds and songbirds are starting to filter through the Bay Area. And to keep them safe and on route, we’re asking people to join in our Lights Out for Birds fall campaign. Birds use the stars to navigate, and bright nighttime lights can disorient them, drawing them off course or into building collisions.

If you’re reading this blog, you probably know the drill by now:

• Turn off or dim lights at night, especially in tall buildings and downtown areas.
• If you have to work late, draw the blinds or use a desk lamp rather than overhead lights.

This season, we’re getting some fabulous cooperation from the City of San Francisco. Spearheaded by the SF Department of the Environment, a number of municipal buildings are committing to Lights Out.

City buildings at 555 Seventh Street, One South Van Ness, and 1650 and 1680 Mission Street have already implemented procedures to dim lights at night, one of many best practices that these buildings consider as certified ENERGY STAR buildings.

Similar efforts to reduce nighttime lighting by working with custodial staff are being planned for 25 and 30 Van Ness, as well as City Hall. Together these buildings account for the majority of city department headquarters, including the Office of Economic and Workforce Development, the Planning Department, the Municipal Transportation Agency, the Public Defender, and the Department of Public Works.

Meanwhile, the San Francisco Unified School District is starting to work with its custodians so that nighttime cleaning crews turn lights on only in the parts of buildings where they’re working. While occupying only one floor of their building, the Department of Environment turns off all of its lights every night in their new offices at 1455 Market Street.

And the San Francisco Public Utilities Commission, whose new building at 525 Golden Gate Avenue was just accredited as LEED platinum, has a sophisticated lighting system with occupancy sensors throughout the structure.

THANK YOU to our friends at SF Department of the Environment and especially to summer intern Andrew Perry in the planning department!

Meanwhile, please help us spread the word about Lights Out. We’d like to involve more owners or managers of commercial buildings in downtown San Francisco and Oakland.

We have flyers and fact sheets that you can download and share with building managers or with work colleagues. Click here for a fact sheet or poster, or see our Lights Out web page for general information about the campaign.…