Monday, January 31, 2011

Big Snow Hatches Big Snowman

 Ever get the feeling you're being followed?
This towering snow beast is keeping watch over the Westminster Conservatory lawn off Hamilton Avenue.

Update, 2/27/11: The snowbeast was being heavily recruited by Princeton University's basketball program before, sad to say, it melted.

The Intelligence of Crows

One of the dropjaw moments in the recent Princeton Environmental Film Festival came in a documentary called "A Murder of Crows". Despite the title, no blood was shed, since "murder" in this situation simply refers to a group of crows, like a gaggle of geese or a pride of lions.

Crows have societies not altogether different from our own. They live on every continent except Antarctica; they mate for life, have complex family structures in which the older siblings stick around for several years, helping their parents raise the newborns; they commute to "work" each day and return to a familiar roost at night; they appear to hold funerals for lost ones, speak to one another in complex ways, and use tools.

It's the tool use that was most stunning, as one crow in the film, seeking a bit of food left in a cage by a scientist, figured out that it could retrieve a little stick from the end of a string, use the little stick to retrieve a longer stick from an enclosure, then use the longer stick to fetch out the morsel tucked otherwise out of reach in a cage.

Much of this has been known for longer than the filmmakers let on, but the photography and story of these "apes with feathers" is compelling. In Princeton, there are two kinds of crows that I know of: the American crow and the fish crow. I'm most aware of the fish crow, whose calls of "uh, uh" during the summer seem like an ongoing critique of the human activities below. Ravens, which are bigger and have a deeper voice, can be found in more mountainous terrain, such as at the Delaware Water Gap an hour north of here.

For more info on crows, click here.

Nabakov and Butterflies

Amateur lepidopterists, take heart. Turns out that Vladimir Nabokov, best known as author of Lolita, "had a parallel existence as a self-taught expert on butterflies", as described recently in the NY Times. The article describes a controversial hypothesis he proposed back in 1945 about how a kind of butterfly known as the Polyommatus blues came to the American continent in five successive waves from Asia, over a period of millions of years. Though Nabokov's hypothesis was given little credence during his lifetime, tests using modern gene-sequencing techniques have proven him correct.

Saturday, January 29, 2011

Winter Wonderland Walk To Proceed As Scheduled

The walk at Mountain Lakes tomorrow, Sunday, Jan. 30, will be aided by the pathbreaking work of all who, with slogged determination have fashioned trails through the deep snow. It helps also that the township plowed part of the Community Park North parking lot at Mountain Ave and 206. In such an alpine landscape, Mountain Brook really looks like a mountain brook. Meet at 1pm at the parking lot.

Friday, January 28, 2011

Hitchhikers In an Umbrella Tree

Safely sheltered from the snow, life beneath the spreading umbrella tree went on much as it always had, until the Keeper of the Village complained one day that her hair had gotten sticky after brushing against the leaves. 
The leaf of a healthy umbrella tree (Schefflera) looks like this.
But some of the new shoots appeared stunted and warped. A closer look revealed little black spots and sticky goo on their undersides.
Time to bring out the trusty microscope, particularly given that a journal entry was due for the Keeper of the Village's 5th grade science class the next day.

Who would have guessed that a little village of aphids had hitchhiked in when the umbrella tree came indoors for the winter.
There was much to learn, about how the aphids suck the juice from the leaves and expel the extra sugar content out their backsides as little balls of honeydew, how ants harvest the honeydew from aphids like we collect milk from cows, and how ants even go so far as to help the aphids overwinter by storing their eggs under optimal conditions underground, then redistributing them to plants come spring.

Snow Update From the Little People

Walking out on the back patio, I noticed that the little people are showing their usual resourcefulness, building homes out of locally abundant materials.
Some vehicles, left abandoned in a previous snow,
are now disappearing altogether under the deluge. Those who thought Princeton to be on high enough ground to survive the coming floods hadn't suspected they could arrive in crystalline form from above.

New playground equipment proposal: For a compact sledding experience freed from the tyranny of topography, consider Sled Swings, featuring sleds hung from chains, adjustable to match snow depth.

Tuesday, January 25, 2011

Nature Walk This Sunday, Jan. 30, 1-3pm

I'll be leading a walk at Mountain Lakes this coming Sunday, January 30, from 1-3pm. We'll do some winter identification of trees and shrubs, and check out the progress on restoring the historic dams. Meet at the Community Park North parking lot, off Mountain Avenue close to its intersection with 206. Check this website for any last-minute cancellations due to weather.

Pollinator Talks at D&R Greenway

UPDATE: The Jan. 27 talk tonight has been postponed due to yesterday's snowstorm.

Two talks on the fabulous diversity of native pollinating insects will be given on January 27th (butterflies) and February 16th (bees) at the DR Greenway's Johnson Education Center, out Rosedale Rd, on Preservation Place. Both events start at 6:30. More info can be found here.

For past posts about all the wonderful pollinators that can be catered to by planting native wildflowers and shrubs in Princeton, try typing words like "bees" into the search box at the top left of this page. The butterfly in this post was feasting on mountain mint growing in the meadows at Tusculum. Projects I've been involved in through Friends of Princeton Open Space to provide habitat for pollinators include the high school ecolab wetland, a field at Mountain Lakes, and the marsh at Rogers Refuge.

Mountain Lakes and the Panama Canal

A PBS documentary last night on the building of the Panama Canal offered a dramatic portrayal of the beginning of the 20th century, when the U.S. was emerging as a world power. Described at the time as "The greatest liberty ever taken with nature", the canal was gnawed out of swamps and mountains with a combination of dynamite, giant steam shovels (think Mike Mulligan), and brutal manual labor. Teddy Roosevelt started the project in 1904. After ten years and 5600 lives lost to landslides and epidemics of yellow fever and malaria, they blew up the last retaining dam, allowing water to fill the final segment of the canal.

Meanwhile, the pre-refrigeration age was all the rage in Princeton (why they didn't include this in the documentary I cannot say). Mountain Lakes Ice Company was harvesting blocks of ice from Mountain Lakes and distributing them to residents and businesses on carts pulled by mules. Small liberties had been taken with Mountain Brook some years prior, when the lower dam was built in 1884, and the upper dam added in 1902.

Steam power (the foundation and chimney are still visible in a thicket of invasive shrubs) was used to transfer the blocks of ice from the lake to the three-story insulated barns for storage.

Maybe this juxtaposition came to mind because just last week, a retaining dam (buried in snow to the left of the restored dam in the photo) built to protect the upper dam during its restoration was removed, albeit not with anything as exciting as dynamite. This spring, the upper dam will return to action, backing up water to refill the upper lake, now restored to its original size and depth.

While the Panama Canal represented a will to overcome nature's obstacles in the name of economic progress, a contrary movement to preserve the great American landscapes began at the same time, as Roosevelt set about protecting lands in 1902.

The Panama Canal happens to play a role in a pathbreaking drama about climate change that debuted last year at the McCarter Theater in Princeton. Called The Great Immensity, its story begins on an island in the middle of a lake created by the canal. Scientists have been conducting a longterm study there to better understand whether populations of wildlife can survive when they become isolated in small fragments of habitat, as has happened to much of New Jersey due to development.

Wouldn't it be nice if the two often conflicting drives--economic expansion and preservation of natural heritage--could converge into what's being called a green economy. Mountain Lakes Preserve is one place where a historical example of a sustainable economy (ice harvest) and land preservation find common ground.

Wednesday, January 19, 2011

A Not So True Blue Jay

Everything I know I learned from helping my 5th grader with her science reports. She asked me what she should write about this week. I said I didn't know. A little while later she was peering through a microscope at a feather, the close inspection of which led to internet searches to find out what she was seeing. 

Rows of barbules, it turned out, which branch off from rows of barbs, which branch off the central rachis of the feather. It's the rows of barbules that can be pulled apart, then preened back together, their hooked ends interknitting to keep a bird in fine feather.

Our internetting also shed light on how blue jays shed light, which is to say very deceptively. Tricksters they are. The blue we see, in sky as well as in feather, is not the sort of blue that comes from pigment, but rather from the way light is scattered.

Lit from the front, a blue jay's feather shows blue--

a blue that fades as the light comes mostly from the back,
then disappears altogether when strongly backlit.

The afternoon's research ended before we could find out if the difference in color between a blue jay and the closely related crow comes not from pigment but solely from the way light bounces off their feathers.

Tuesday, January 18, 2011

Crows, Coffee Habitat, and Olmsted Today at Library

Today at the Princeton Public Library Film Festival,
  • a movie on those highly intelligent animals called crows at 4pm. 
  • At 6pm, a short film on the importance of shade-grown coffee for migratory birds, and at 
  • 7pm, a great documentary about Frederick Law Olmsted, who designed many parks, including Central Park and Trenton's Cadwalader Park.
Pertaining to the 6pm film, coffee grows naturally in the understory of forests, but a strain was developed that could be planted in full sun, leading to the cutting down of many forests and resultant loss of bird habitat. Some coffee companies feature shade-grown coffee--a good way to support one's habit and habitat at the same time.

The Story of STRAW

I was asked to speak at the public library this past Saturday after a showing of the inspiring documentary, The Story of STRAW. Contrary to the appearance of the title, the film does not describe how grass stalks are baled, but instead tells the story of how a classroom of kids and devoted teachers changed the fate of an endangered freshwater shrimp in a California watershed. The shrimp had fallen on hard times because their stream habitat had become degraded over time. Where once there were trees to hold the soil, shade the water, and offer exposed underwater roots for the shrimp to hide among, there were now cows tromping up and down eroded banks to graze on the grass.

Out of a young student's simple question, "What can we do?", was born Students and Teachers Restoring A Watershed. Working with ranchers, they fenced off the stream and planted willows along some 20 miles. The willows grew into a wooded corridor to protect the stream, shrimp numbers rebounded, birds and other wildlife returned to the watershed, and the group won a prestigious prize. An effort, apparently successful, was made to incorporate the work into the school's curriculum, boding well for the program's longevity.

The film brought back memories of one my first formative environmental experiences. A few times as a kid, I talked my dad into driving me to various streams to fish. Each time, the vision in my mind was of a healthy stream packed with smallmouth bass. What we encountered instead were textbook cases of environmental degradation and the destructive impact of invasive species. A waterway called Turtle Creek, for instance, looked promising on the map, but when we arrived, we found a muddy stream flowing through a cow pasture. Carp had taken the place of smallmouth bass. That creek, and I'm sure many others in Wisconsin's dairyland at that time, were in need of the same restoration STRAW was able to bring about in their California watershed.

A compelling vision of healthy ecosystems drives most anyone who finds themselves cutting down invasive shrubs or hauling water down a path to newly planted trees. It's a challenge, however, to translate the movie's appealing message of reforestation to the realities of Princeton's open space. The work of reforesting Princeton's cow pastures was done decades ago by the trees themselves, when most of the farms were left to go fallow. Human effort has been channeled into saving the land from development--work that began at least 40 years ago and continues to this day.

The restoration needing to be done involves not the sort of reforestation that makes for dramatic before and after photos, but a more subtle reestablishment of non-woody plants--wildflowers, grasses and so forth--that were obliterated by the plow and have not made as successful a return as the trees.

The locations in Princeton most like the pastures in the movie are retention basins--those curious looking turfy hollows carved out to catch runoff from developments. They offer a nice clean slate into which can be planted the many native species that like wet, sunny locations. Two of these--one at the Princeton High School, the other below the soccer fields at Farmview Fields on the Great Road--we've successfully transformed from turf over to native habitat.

Another inspirational project of this sort, that like the movie includes a great deal of participation by children, is in Ann Arbor, MI, where a vast swath of unused turf in an urban park was recontoured to catch runoff and host a rich assortment of native wildflowers, grasses and sedges. Prescribed burns make for an elegant and safely executed means of cleaning the plantings up each spring.

Saturday, January 15, 2011

Fabien Cousteau

The grandson of Jacques-Yves Cousteau brought his passion for the oceans to the Princeton Environmental Film Festival last night. Flashing a boyish grin in front of an overflow crowd, he mixed stories from his family's fabled explorations of the oceans with humorous asides to the kids sitting on the floor in front, and urgent calls to action to save the oceans.

"Everything that happens on land", he said, "ends up in the oceans." Though he didn't put it quite this way, for Princeton that means that everything that runs off of our yards and streets, and all the choices we make as consumers of fish, has a small but meaningful impact on the ocean. The power of the individual was a recurring theme, as he called on us to avoid "single-use plastics",  to download info from about which fish to buy, and to use social networks to help bring about change.

An interview that captures much of what he said can be found at, though it may not mention the lifelike shark capsule he built to swim anonymously among sharks. Info on his program to bring back the oysters in the Hudson Bay are at

A couple posts describing our link to the ocean, better known as the Millstone River, can be found on this website by scrolling down to November, 2010.

Friday, January 14, 2011

Light Recycling

Shadows of late afternoon stretch across the lower Mountain Lake, emptied last summer in preparation for restoration of the dam. Snow may be a chore to shovel, but it can otherwise lift the mood by recycling winter's meager allotment of light.

I learned the value of this the hard way, through years spent in southeastern Michigan, when the mind was slowly drained of color and light by an endless progression of gray clouds above the landscape's drab offerings of brown. By February, all memories of color stored from autumn had faded, and the mind grew desperate for spring green. After two weeks of gray, a patch of blue sky would come as a revelation, and occasional snows brought the gift of recycled light, making winter seem brighter in much the same way a wall of mirrors makes a room appear larger.

Snow cover, like the polar ice caps, glaciers and white roofs, also helps reflect solar radiation back out into space--a strategically important bit of reflection on a planet growing ever more absorptive of the sun's energy.

Dam Restoration Update

Restoration of the historic upper dam at Princeton's Mountain Lakes Preserve is nearing completion, with refilling of the upper lake promised, or at least predicted, to come in March or April.
The broad spillway of the dam, capped with concrete, needs to be perfectly horizontal in order to prevent overflow from concentrating in one place. The apparent tilt of the wall has more to do with the camera lens than the actual dam.

Tuesday, January 11, 2011

Urban Beekeeping

An interesting article on growing honey bees in the city. It's now legal in some places. I know someone who has a beehive in his suburban garage, with a little hole in the back wall for them to come and go.

In particular, one beekeeper interviewed says that, if you grow bees, you start thinking like a bee and want to transform the landscape to make it more bee-friendly. If there's a beekeeper in the neighborhood, fruit trees bear more fruit, including arctic kiwi--a frost tolerant version of the fruit that grows in northern latitudes. (A friend tells me at least one Princeton resident is growing them--kiwis, that is--with very good results.) Bees, then, can help in the process of re-imagining a neighborhood.

I was surprised to learn, back in the early '90s when the honeybee population crashed due to an introduced mite, that honey bees are not native to America. The photo, from a 2008 post, shows a couple honeybees mixed with some native pollinators on the flowers of boneset, a native wildflower that becomes the insect world's favorite food court every August.

Wednesday, January 05, 2011

Upcoming Exhibit and Presentation on Farming In and Around Princeton

This coming Monday, January 10, there will be two events at the Princeton Public Library under the title: "Farming In and Around Princeton: Past, Present, and Future"

I've been invited to be on the panel that's part of a presentation at 7:30pm. Some of my comments will have to do with an out-of-culture experience I had several years ago returning to Princeton from Spain. 

MORE INFO: Judith Robinson, manager of the Princeton Farmers Market, has organized with the assistance of the Historical Society of Princeton an exhibit of photos and pages of farm ledgers from the 1800's which will be on display on January 10th at 11:00am in the community room of the Princeton Public Library. Then at 7:30pm she will be showing a short documentary on two local farmers which will be followed by a panel discussion including Elric Endersby, Stephen Hiltner, Jess Niederer, Jennifer Jang and moderated by Ms. Robinson.

"I want to make people aware of and get them interested in learning about both the history of farming in the area and in what is happening now---and what they could be active in contributing to by supporting our local farmers and even plowing up their grass yards! To see this area not only as suburbia but in its potential for creative husbandry", she says.
info 609-356-0558