Carnegie Museum of Natural History

One of the Four Carnegie Museums of Pittsburgh

Patrick McShea

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Robin Watch

(above) The American Robin Box in the CMNH Educator Loan Program, with art work by John Franc. The loaning of educational materials has been suspended during the Covid-19 pandemic.

As a bird watcher, I’m out of the house early at this time of the year, listening for the calls of newly arrived migrating birds. New days begin in a still dark neighborhood with a steadily growing feathered chorus. Although the calls of a few Northern cardinals and Carolina wrens are close enough for me to guess the location of each singers’ perch, they are far outnumbered by American robins whose blended notes reach my ears from every compass point.

On recent mornings I’ve come to value the abundant presence of robins as a tonic to human nerves frazzled by the life-disrupting spread of Covid-19. The species’ horizon-wide dawn concert is a prelude to an active visible presence in the same territory all day. With minimal effort, little prior planning, and without violating protocol for social distance spacing, you can observe robins flying to and from cover, hopping over grassy feeding areas in search of worms, fighting rivals for mates and territory, and even gathering dried grass and mud for nest construction.

Photo by Amy Henrici.

Through such simple observations it’s possible to reach what naturalist Margaret Renkl, writing recently in The New York Times, termed “the alternate world we need right now, one that exists far beyond the impulse to scroll and scroll.”

A pre-pandemic, but still contemporary call for all of us to become better robin watchers can be found in A Season On The Wind, ornithologist Ken Kaufman’s 2019 account of spring bird migration near his home along the Lake Erie shore in western Ohio.

“Their songs are loud and rich and their colors are bold, from the deep yellow of the beak to the bright rufous orange of the chest. If the American robin were a rare bird, we would climb mountains or walk through fire to catch a glimpse of it. Why should we appreciate it any less just because it’s around us every day?”     (A SEASON ON THE WIND, Inside the World of Spring Migration, Houghton Mifflin Harcourt, 2019.)

A far older robin endorsement can be found in the writings of John James Audubon. In early June of 1833, when the renowned bird artist arrived on the barren coast of Labrador, he encountered a robin singing from a snow-free patch of grass.

“That song brought with it a thousand pleasing associations referring to the beloved land of my youth, and soon inspired me with resolution to persevere in my hazardous enterprise.”

Audubon’s praise for the species continues for several paragraphs, and his deep appreciation for the wide-ranging bird includes an aspect unfamiliar to modern robin watchers. After describing how wintering robins in the American south feed on “the fruits of our woods,” he reminds readers that under these circumstances “they are fat and juicy and afford excellent eating.”

For more information about robins including song recordings:

https://www.allaboutbirds.org/guide/American_Robin/id

For read a fuller account of Audubon’s praise for robins:

https://www.audubon.org/birds-of-america/american-robin

For Margaret Renkl’s full essay about the value of nature observation:

https://www.nytimes.com/2020/03/23/opinion/coronavirus-nature-outdoors.html

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Summer Dreaming

At this time of year, the sight of some battered bird-built structures can trigger summer dreams. Consider the Baltimore Oriole nest dangling from a linden branch above a Flagstaff Hill sidewalk in Pittsburgh’s Schenley Park.  Watch the bundle of plant fiber and ribbon scraps sway in a cold late winter wind and you might be able to imagine the nest partially concealed by bright green leaves and periodically visited by a bird with goldfish-orange feathers.

Baltimore Oriole pair in CMNH Bird Hall with nest and nest cross-section.

Such out of season thoughts are far from original. One hundred and sixty-one years ago, and some 500 miles northeast of Pittsburgh, naturalist Henry David Thoreau used a different common name for the species when he referenced the bright and melodic warm season residents in a winter journal entry.

What a reminiscence of summer, a fiery hangbird’s nest dangling from an elm over the road when perhaps the thermometer is down to -20, and the traveler goes beating his arms beneath it! It is hard to recall the strain of that bird then.

Henry David Thoreau – journal entry                                                                                                           December 22, 1859

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Big Foot

Studying anatomical details on taxidermy mounts can enhance field observations of wildlife. A common loon in the museum’s Discovery Basecamp, offers a great example of this benefit.

Within an acrylic-sided display box, the nearly two-foot long stuffed bird rests on a tiny simulated mud island, as if the spear-billed creature just waddled from the water on its large and widely-spaced webbed feet.

Common loons don’t do much waddling from the water in western Pennsylvania. That behavior occurs much farther north where the species’ summer range includes much of Canada and a northerly strip of the US stretching eastward from the upper Great Lakes to New England. Here the fish-eating birds push themselves from the waters of their home lakes mostly to reach immediately adjacent nests.

Photo by Steve Gosser.

Loons do make seasonal appearances on Pittsburgh area waters during migration rest stops, however. Although their big feet aren’t visible to shore-bound observers during these visits, it’s the hidden actions of the flexible spatula-sized paddles, that makes loon watching such a challenging endeavor.  

Just when you bring a resting loon into binocular focus, the bird can disappear in a minute-long feeding dive and reappear, in an unpredictable direction, many yards from its original location.

The bird’s unseen propulsion is well explained in a 2012 post in Maine Birds, a blog by Colby College biology professor Herb Wilson.

When a loon is first diving from the surface, it breaks the surface by alternating strokes with the left and right leg.  Once underwater, the legs beat synchronously.

The lateral placement of the legs makes for hydrodynamic efficiency.  If the legs were close together, the turbulent eddies created by one leg would interfere with smooth movement through the water of the other leg.  The lateral arrangement allows a loon to generate maximum thrust while minimizing hydrodynamic drag.

The feet of loons are large and webbed.  The real power in swimming is generated by the rearward movement of those webbed feet against the water.  When the loon moves its feet forward during the recovery stroke, the toes are brought together causing the web to collapse and minimizing the effort needed to get the foot ready for the next power stroke.

Spring appearances of migrating loons in western Pennsylvania normally occur between mid-March and early May. Forty miles north of Pittsburgh, common loons are known to visit the deep water sections of Lake Arthur in Moraine State Park.

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Bright Flying Mammal

museum display of mammals found in Pennsylvania
Mammals of Pennsylvania within the Hall of North American Wildlife

Can you name our region’s most colorful mammal? If the question was asked in front of the museum’s Mammals of Pennsylvania display, many people would choose the red fox near the center of the exhibit’s floor-level row.

Five feet above fox, and just inches from the tip of a raccoon’s tail, a far smaller, but equally bright alternate exists in the form of a gliding eastern red bat.

Eastern red bat
Eastern Red Bat, known to science as Lasiurus borealis

In color, red bat fur ranges from golden brown to bright rusty orange, with males typically sporting brighter shades than females. The bright fur coats of this widespread insect-eating species provide surprisingly effective camouflage when the bats are at rest. Red bats are tree bats, a term that indicates the species’ preference for spending daylight hours roosting within the foliage of deciduous and sometimes evergreen trees.

Eastern red bat
Eastern Red Bat

With wings folded, they hang upside-down from the grip of a single foot, looking, to casual observers, like dead leaves or pine cones.

Red Bats have so far escaped the devastating effects of white-nose syndrome, a fungal disease that since 2007 has caused mortality rates as high as 90% at hibernation sites of many other bat species. Remarkably, on fall migration flights to southern portions of their North American range, red bats have been known to cross long stretches of territory with flocks of migrating birds.

For more information about eastern red bats, please check the species account prepared by Bat Conservation International.

For information about the vital ecosystem contributions of the world’s 1,300 bat species please visit Merlin Tuttle’s Bat Conservation.

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Don’t Overlook the Lichens

various lichen on rock

Lichens are scenery elements in many museum dioramas. Within the Pronghorn Antelope diorama in the Hall of North American Wildlife, for example, these frequently overlooked organisms coat a foreground boulder with irregular patches of gray, red, and gold.

pronghorn antelope diorama

If you approach this artfully recreated western scene with a little background information about lichens, you might find the colorful cluster of immobile organisms in the bottom right corner just as interesting as the four galloping centerpieces.

Lichens are found on every continent and estimates of their global diversity range from 13,000 to more than 17,000 species. Every lichen is a partnership of two different organisms, a fungus whose tissue provides the physical structure to support a second organism capable of photosynthesis. For most lichens the partner with the solar energy power is some form of green algae.  The fungus/algae partnership is a living arrangement in which separate identities fade while combined abilities allow for survival in locations where neither organism could live alone.

Crustose or curst-like lichen and pronghorn antelope scat.

Three distinctive growth forms provide a means for categorizing lichen. The colorful trio sharing the pronghorn antelope diorama are termed “crustose” or crust-like lichens. Lichens with a leaf-like appearance and structure are termed “foliose,” and those with shrubby upright or dangling strands are termed “fruticose.”

Because lichens absorb so much of their nourishment from the air and rainfall, they serve as living air quality indicators. By monitoring a region’s changing balance of pollution sensitive species and pollution tolerant species, a researcher can visually chart the build-up or decrease of pollutants such as sulfur dioxide and nitrogen dioxide.

For more detailed information about lichen ecology, including information about local research efforts, please visit the site maintained by Point Park University Professor Matthew Opdyke.

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

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Frontier History Wizards

white snakeroot plant
White snakeroot blooming along the Allegheny River shoreline in early August.

Written descriptions for Carnegie Museum of Natural History summer camp, Wizard Academy, invite 8 – 10-year-old participants to experience a collision between “magic and science.” Based upon my recent experience with campers in the popular Harry Potter-themed program, the advertised subject could also include “history.”

During a discussion of poisonous plants with two dozen want-to-be wizards in the Hall of Botany, I drew the group’s attention to a display labeled “LOCAL SPECIES TO AVOID.”

The focus for my remarks was white snakeroot (Ageratina altissima) a straight-stemmed and flower-topped species in the display’s front row. I explained how the plant’s common name is an historic reference to its alleged value in treating snake bites, and that its designation as a plant to avoid was based upon on its connection to an often-fatal illness know as milk sickness.

The disease, which occurred when people drank milk from cows that had fed upon white snakeroot, was a scourge of pioneer life during the early nineteenth century, the decades-long period when settlement across what was then the American frontier dramatically altered vast forests west of the Appalachians.

One of the campers assisted my narration by reading from a handout about how Abraham Lincoln’s mother, Nancy Hanks Lincoln, died from milk sickness. When another camper asked how the plant-to-cow connection was “figured-out,” I confessed ignorance but promised to find out.

herbarium sheet of white snakeroot
White snakeroot herbarium sheet, part of the Educator Loan Collection’s “Poisonous Plants of Pennsylvania” box.

Much of the life-saving credit, I learned, belongs to a pair of women whose friendship crossed conflicting cultures of 1820’s Illinois; a frontier doctor, and an elderly fugitive of the federal government’s forced relocation of the Shawnee to territory further west. The doctor, Anna Pierce, lost family members to milk sickness and, based upon observations of disease occurrence, promoted the avoidance of milk drinking between June and the plant-killing frosts of autumn. The relocation resister, known to settlers as Aunt Shawnee, took Dr. Pierce into the woods to show her white snakeroot and explain the plant’s lethal properties. Pierce then conducted experiments to confirm the plant’s toxicity and shared her findings with other doctors.

More than 70 years later carefully controlled scientific studies documented year-to-year and geographic variations in the toxicity levels of white snakeroot, but it wasn’t until 1928 that the plant’s toxic chemical, an alcohol termed tremetol was isolated in a laboratory. Today, largely because of better pasture management, milk sickness is not a concern in commercial dairy operations.

The takeaway lesson, kindled when a ten-year-old camper’s question illuminated a nearly 200-year-old ethnobotany story, is to more fully value the indigenous knowledge of the vibrant Native cultures that continue to exist across our country.

(Information source: Natural History, July 1990, “Land of Milk and Honey” by David Duffy Cameron)

Patrick McShea works in the Education and Visitor Experience department of Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.