9/11 Tribute in Light: bird monitoring.

You can see them from sixty miles away: twin beams of light reaching from lower Manhattan into the highest visible reaches of the sky. The beams burn through the night on September 11th, a memory, a tribute in light made from 88 7000W xenon bulbs.

Also in the New York skies in mid-September: hundreds of thousands of migrating birds. From afar, the beams look to the birds like…we don’t know…perhaps moonlight, or a gleam of sun out of place, or a streak of magnetic weirdness across the birds’ inner eye. The birds are drawn to the beams, then snared by the light. Look up from the ground and you see hundreds of circling birds. Through binoculars, the higher parts of the beams are so full of birds that the clouds of illuminated bodies look like the Milky Way in motion. Thousands of warblers, orioles, woodpeckers, and thrushes, each turned to a silvery mote.

I joined NYC Audubon to monitor and count birds at the tribute. We watched from the Battery Rooftop Garden, a terrace filled with fruit trees and vegetable beds 34 stories above the street, right next to the beams.

When the bird count got too high, the operators of the 9/11 memorial extinguished the beams for a few minutes, allowing the birds to escape from their photonic prison. Winged creatures in motion, animating the memorial beams, then released.

Looking directly up from a few blocks east of ground zero: The Tribute in Light lancing the sky. The bright spot along each beam is a thin cloud layer.

Closer to the lights, the birds are visible in each beam.

Twin beams. They’re parallel, but seem to converge high in the sky.

From the rooftop gardens on a building near One World Trade.

Counting birds in the beams. We’re 34 stories above the street.

A 1/6 second exposure: the flight path of each bird is revealed.

 

Red (white and blue) carpet for migrant birds

They’re forest beacons, glowing come-hithers to migrant birds. These gene catapults, each carrying a plant’s hope for another generation, are ripening this week in Sewanee and across the eastern US. Not coincidentally, thrushes and other south-bound birds are also on the move (see BirdCast for the feathered forecast near you).

Some fruits from the woods near Sewanee:

 

The Songs of Trees: airwaves

PRI and the BBC have recently run a couple of short interviews combined with my field recordings of trees. I hope you’ll enjoy these acoustic experiences. They’re best listened to with earbuds or speakers, but the vibe comes through even on a phone.

BBC World Service’s Outlook. I was in a studio in Nashville talking via satellite with Joel Cox in the UK. Joel then layered sounds into clips of the interview. I love the changing sonic texture, drawn from many of the trees that I write about in the book.

PRI’s The World. I recorded this interview in Boston, in studio and at the Arnold Arboretum. Carolyn Beeler and I talked about the book and about the process of listening. She then wove some of my field recordings into our conversation, along with pictures for the webpage. She does a fabulous job of using multiple avenues into the story of people-tree connections.

It’s a great honor to be featured on these shows. I hope you’ll enjoy the great work of the presenters and editors.

Update on upcoming events:

Asheville, NC: Malaprop’s Bookstore. May 31st, 2017.

New York, NY: Metropolitan Society of Natural Historians. June 3rd, 2017. Register here. [Other NYC events TBA. I’m in the city for much of the summer and open to venue suggestions.]

Easton, MD: Adkins Arboretum. June 8th, 2017. 4pm – 6pm at the Academy Art Museum 106 South Street.

Millbrook, NY: Cary Institute of Ecosystem Studies. June 9th.

Sewanee, TN: School of Letters. 4:30pm June 28th, 2017.

Clermont, KY: SONICBernheim. July 9th, 2017.

Sewanee, TN: Young Writers’ Conference. July 10th, 2017.

Life is network. (And book update.)

My musings on leaf biology, familiar to Ramble readers who might remember my fungus experiment, are featured in this month’s NPR blog. I wrote a guest article discussing the networked nature of maple leaves (and all life…).

I’ve been on the road giving readings from The Songs of Trees. Thank you to all who’ve come out! Upcoming venues include Nashville, Portland (OR), Corvallis, San Francisco, Denver, and Pasadena. I’ll be in Asheville, St Louis, Millbrook (NY), and Maryland later in the season. I hope to have one or more NYC events as well.

If you’ve read the book and have thoughts about its stories and voice, please submit comments/review at Amazon’s book page!

 

 

 

 

 

The Songs of Trees, published today

New book, published today:

After five years of growth in the underground humus of writing and editing, The Songs of Trees: Stories from Nature’s Great Connectors has lifted its leaves into the sunlight.

Ed Yong, writing this morning in The Atlantic.com, gives a great overview of the book.

You can purchase the book at bookstores or online. Many libraries have copies on the shelves. Links to bookstores:

IndieBound (connect to local bookstores), Amazon, Barnes and Noble, Books-A-Million, iBooks

Over several years I visited a dozen trees, sitting with each to listen to its story. The trees are located in very different places – the Amazon rainforest, Shakerag Hollow in Sewanee, the Damascus Gate in Jerusalem, a city park in Denver, an ancient hearth in Scotland – but they all, in their own ways, tell of life’s surprising interconnections.

The book’s web pages have more information about the book, including sound clips, photographs, a Q&A, and advance praise from writers and scientists. Outside Magazine just published a profile of my work by Paul Kvinta, featuring the Manhattan street tree that I befriend in one of the book’s chapters.

I hope you’ll enjoy these tales of biology and human culture. I’d be very grateful if you’d consider sharing news of the book’s publication with friends and family.

With my gratitude,

David

Lectures and readings:

I’ll be speaking at the following venues in the coming months, with more to be announced soon. I’d love to see you there. If you have friends or family who might be interested, please pass along the date.

Tacoma, WA: Slater Museum, University of Puget Sound. April 7th, 2pm.

Tacoma, WA: King’s Books. April 7th, 7pm.

Seattle: Town Hall Seattle, 1119 8th Ave, Seattle, WA. April 8th, 7:30pm.

Cambridge/Boston, MA: Arnold Arboretum and Harvard Museums of Science and Culture. 6pm, April 12th, 2017.

Sewanee, TN: University of the South. Convocation Hall. 4:30pm, April 17th.

Chattanooga, TN: Benwood Auditorium, University of Tennessee Chattanooga. April 18th, 7pm. Lecture to benefit Tennessee River Gorge Trust. Hosted by the UTC Department of Biology, Geology and Environmental Science.

Oxford, MS: University of Mississippi. April 20th, 2017.

Atlanta, GA: Atlanta Audubon and Chattahoochee Nature Center. 6pm, April 22nd, 2017, reservation required. (Location: Chattahoochee Nature Center, 9135 Willeo Road, Roswell, GA 30075)

Nashville, TN: Parnassus Books. April 30th, 2pm.

Portland, OR: Powell’s Books. May 3rd, 2017. (7:30pm, Powell’s City of Books, 1005 W. Burnside St., Portland.)

Denver, CO: Tattered Cover Bookstore. 7pm May 4th, 2017. (LoDo store: 1628 16th Street, Denver)

Point Reyes Station, CA: Point Reyes Books. May 7th, 2017.

San Francisco, CA: California Institute of Integral Studies. May 10th, 2017.

Pasadena, CA: Vroman’s Bookstore. 7pm, May 11th, 2017.

Asheville, NC: Malaprop’s Bookstore. May 31st, 2017.

Easton, MD: Adkins Arboretum. June 8th, 2017. 4pm – 6pm at the Academy Art Museum 106 South Street.

Millbrook, NY: Cary Institute of Ecosystem Studies. June 9th.

Sewanee, TN: Young Writers’ Conference. July 10th, 2017.

St Louis, MO: Missouri Botanical Garden. July 25th, 2017. Wild Ideas Worth Sharing Speaker Series and Visualizing Biodiversity for a Better World.

Byron Bay, Australia: Byron Bay Writers Festival. August 4-6, 2017.

Canberra, Australia: National Library of Australia. August 9th, 2017.

Bendigo, Australia: Bendigo Writers Festival. August 11-13, 2017.

Nashville, TN: Southern Festival of Books, Nashville, TN. Oct 13th and 14th, 2017.

Fairlee, VT: Northern Woodlands Conference. The Hulbert Outdoor Center. Oct 20th-22nd, 2017.

Birmingham, AL: Audubon Society. Dec 7th, 2017.

The bolt of natural selection

Oberon:

“Yet mark’d I where the bolt of Cupid fell:
It fell upon a little western flower,
Before milk-white, now purple with love’s wound”


Hepatica unfurls its advertisements in both white and purple. This is true of North American species and those in Asia. Why the variation? Natural selection or genetic drift eliminates variation in a population unless some force keeps these purgative pressures at bay. In the case of Hepatica, the costs and benefits of white and purple flowers have not been measured in the wild (readers, correct me if I’m wrong here, please!).  Midwestern populations are more purple than their eastern cousins.

Could pollinators or the light environment be creating different selection pressures? Many populations contain a mix of colors (white is the most common here in Sewanee, but purples are scattered among them in significant numbers), so selection does not seem to favor just one color in each location.

In spring beauty flowers (Claytonia), flowers come in red, white, and intermediate. Natural selection acts on flower color in this species complex ways. Redder flowers are more attractive to pollinators, but whiter flowers have more flavonols, chemicals that act as herbivore deterrents. So, white flowers receive fewer pollinators but red flowers get more damage from slugs. Damage from herbivory changes from year to year and from place to place. So two opposing forces — pollination and herbivory — vary in space and time, resulting in a mix of flower colors. Perhaps a similar turbulent, Puckish convergence of forces also acts on Hepatica?