Sometimes it's hard to imagine that we humans are part of the natural world. We think we are outside of Nature, instead we are intricately entwined. This special exhibit at the Carnegie Museum of Natural History shows how we affect Nature and are affected by it.
We Are Nature: Living in the Anthropocene tells many stories of our impact on Earth by focusing on five areas: pollution, extinction, PostNatural (intentionally altered organisms), climate change, and habitat alteration.
Some of our effects are so common we forget they wouldn't exist without us. Dogs, for example. They're in the PostNatural category.
We also tinker with wild things like wolves. The plaque below this animal says:
"A Trickle-Down Effect (Trophic Cascade): Humans eliminated gray wolves from Yellowstone National Park in the 1920s. In 1995, 31 gray wolves were reintroduced to the park from Canada; the wolf population is now considered stable. While some ranchers may not agree, the return of wolves to Yellowstone, coupled with other ecological factors, has had positive effects on biodiversity and the health of the park."
But most of our effects occur when we aren't paying attention.
Acid rain is a byproduct of burning coal to generate electricity. We had no idea this made a difference until we noticed that our downwind lakes were becoming acidic. More than a water problem, acid rain makes land snails scarce and causes declines in ovenbird breeding success. An exhibit of tiger snails says:
Tiger Snail + Acid Rain: Acid rain from human pollution harms some of Pennsylvania's smallest animals: tiger snails. ... Museum scientist Tim Pearce found that before 2000, the tiger snail was found in 53 Pennsylvania counties. After 2000, that number was cut by more than half.
There's one object in the room that's the perfect emblem of our aimless effect on earth -- a shopping cart coated in zebra mussels.
The shopping cart says, "Humans were here."
Humans manufactured something not found in nature.
The cart ended up in one of the Great Lakes through human negligence (it rolled) or purpose (dumped).
As it lay submerged zebra mussels attached themselves to the cart. Zebra mussels are an invasive species accidentally introduced to the Great Lakes in the 1980s. They got there on the bottoms of boats.
Without humans, nothing about this object would exist.
p.s. In the Post-Gazette I learned that this is the first exhibition about the Anthropocene in North America. (Go, Pittsburgh!) It will run for a year, include additional programming, and the museum plans to hire a curator of the Anthropocene in January.
In its first year of life, the plant is a basal rosette of velvety blue-green leaves, 4-16 inches long.
In its second year the rosette sprouts a flower spike, blooms in the summer, sets seed, and then dies.
Here it is in the spring of its second year. The basal rosette is beginning to flower.
And here's a closeup of the flowers:
Though common mullein only reproduces by seed it's very good at doing it. Each plant produces 100,000 to 180,000 seeds that are dispersed by wind or animals. If the seeds don't land in a hospitable place, no problem. They're viable for 100 years!
Because it only spreads by seed, this plant can be eradicated by hand pulling before the seed sets, then bagging it and disposing of it. Unfortunately, it's too late in the season to do that now and other methods, such as poison, will only spread its seeds when the plant falls.
We'll just have to enjoy its flowers and wait until next year.
A bird this unusual must surely be from the tropics, but not this one.
The Eurasian spoonbill (Platalea leucorodia) is a large white wading bird with black legs and a spatulate bill that's black with a yellow tip. In breeding plumage they have feather crests and yellow chins. Click here for another view.
Spoonbills live in fresh and saltwater wetlands where they hunt for prey by sweeping their long bills side to side below the surface, snapping them shut when they feel prey close by.
Amazingly this spoonbill nests in both temperate and tropical zones. Though they're sparse in Europe, their range extends to Africa and wide swaths of Asia (see map). Four hundred years ago Eurasian spoonbills disappeared from the British Isles. Happily, they returned to breed in the marshes of Norfolk County in 2010.
Of the six spoonbill species on Earth, all but one are white. The pink one lives in our hemisphere, the roseate spoonbill (Platalea ajaja).
Click here to see the six species of spoonbills, Platalea. Ours is the one with "A ha ha!" in his name: Platalea ajaja!
Eurasian spoonbill by Andreas Trepte, www.photo-natur.net, via Wikimedia Commons
map of European breeding range from Wikimedia Commons; click on the map to see the original
Roseate spoonbill by Steve Gosser)
Did you know that your fingers will go numb or burn if you handle this bird? You'll be lucky if that's all that happens. This bird is poisonous!
Though it superficially resembles our orchard oriole the hooded pitohui (Pitohui dichrous) is an Old World oriole that lives on the islands of New Guinea. Its skin and feathers are poisonous to touch though not as deadly as the golden poison frog of South America shown below. Both animals exude batrachotoxin, a deadly neurotoxin that kills by paralysis and cardiac arrest. The frog is 50 times more poisonous than the bird. He contains enough poison to kill 10 men!
These animals are poisonous because they eat poisonous insects and yet they don't die!
The exhibit explores our relationships with poison in nature including how we avoid it, work around it, use it to kill or use it to cure. Throughout it all we are fascinated by its power. Here are a few of the cool things you'll see:
A terrarium with live golden poison frogs! (Find out why these particular frogs are harmless.)
Foods we eat that are/were partly poisonous. How about cashews?
The real poisons behind famous literary scenes in Macbeth's witches' brew, Alice in Wonderland's Mad Hatter, Sherlock Holmes and Agatha Christie.
What killed the Borgias' enemies? Cleopatra? Ponce de Leon?
Poisons that cure cancer and treat high blood pressure.
In the end you'll get to test your skills with solve-it-yourself poison mysteries.
Visit the Carnegie Museum's The Power of Poisonexhibit, now through September 4, and find out what's surprisingly poisonous.
In late May, you'll see white fluff in the air as you search the sky for birds. It's not dandelion fluff. This is cottonwood season.
The eastern cottonwood (Populus deltoides) grows in open and riparian habitats from the Rockies to the southeastern coast. Western Pennsylvania is on the eastern edge of their range.
Cottonwoods are one of the fastest growing and largest trees in North America. Reaching up to 130 feet tall the trunk can be more than five feet across. The trees require bare soil and full sun to germinate so you usually see them out in the open, sometimes alone.
Their species name, deltoides, describes the leaf shape that looks a lot like aspens. Both trees are in the willow family.
In early spring cottonwoods sprout male and female catkins. The females are fertilized by wind-blown pollen and become drooping strings of seed capsules. In May the capsules burst open to release thousands of tiny seeds, each one attached to a bit of "cotton" that carries it on the wind. (The brown spots in this photo are seed capsule covers, not the seeds.)
The fluff breaks off and blows away but each tree is so prolific that in windless conditions, when the fluff falls straight to the ground, it looks like snow.
Do you want to see a lot of cottonwood fluff? Drive north on Route 528 from the bridge over Moraine State Park's Lake Arthur. Eventually cottonwoods are on both sides of the road.
There's fluff in the air there!
fluff on the ground by Chris Evans, University of Illinois, Bugwood.org
range map from Wikimedia Commons; click on the image to see the original
clump of cottonwood trees by Steven Katovich, USDA Forest Service, Bugwood.org
cottonwood leaves by T. Davis Sydnor, The Ohio State University, Bugwood.org
cottonwood seeds on the branch by Troy Evans, Great Smoky Mountains National Park, Bugwood.org)
I'm taking a break from peregrines today. Here's a plant. 🙂
In Schenley Park, mayapples (Podophyllum peltatum) bloom in April and fruit in May. The plants must have two leaves to produce a flower because the flower stalk grows from the Y between the leaves.
Here's what they look like when they bloom.
The fertilized flower transitions from flower to apple in May, as shown in the photo at top.
You can eat a mayapple when it's ripe but Be Careful! The entire plant is poisonous and the apple is only edible when ripe! Find out more and see a mayapple sliced open in this vintage article from 2011: Eating Mayapples
(top photo by Kate St. John. Blooming photo from Wikimedia Commons; click on the image to see the original)