11 January 2016

Earth’s life history is in its rocks, layer upon layer, each one with a name.  Even if we can’t name all the geologic periods, we know at least one of them because of a movie — Jurassic Park.

Geoscientists identify epochs by the fossils and minerals they find in them.  Even the boundaries are interesting.  The Cretaceous period ends in a thin line, called the K-Pg (was K-T) boundary, that contains iridium from the asteroid that killed the dinosaurs. There the Cretaceous period (K) ended and the Paleogene (Pg) began. Above the line are seven epochs including the Holocene, the most recent 11,700 years in which human population has expanded and thrived.

Now pretend you’re a geoscientist 10 million years in the future and you’re identifying epochs in the rocks.  You see the K-Pg line and the seven epochs, and then on top of them, everywhere around the globe in rocks and ice, you find a layer containing substances never before seen on Earth or in outer space:  aluminum, concrete, plastics, fly ash (below) and nuclear fallout.

The substances are so unique that, as a geoscientist, you must define this layer as a new geologic epoch and name it for its distinctive feature. The substances were created by humans. The epoch is called the Anthropocene.

Since atmospheric chemist Paul Crutzen first proposed the Anthropocene as a geologic epoch in 2000, the idea has taken hold in the scientific community. An international working group is studying the evidence to determine whether the epoch should be formally accepted into the geologic time scale by the International Union of Geological Sciences.  Their recommendation is still postponed.

Meanwhile, the Anthropocene Working Group reported last week that the evidence is overwhelming.  Here’s their description of the epoch from an earlier report:

Members of the international working group formally analyzing the Anthropocene suggest that the key turning point happened in the mid-twentieth century. This was when humans did not just leave traces of their actions, but began to alter the whole Earth system. There was a ‘Great Acceleration’ of population, of carbon emissions, of species invasions and extinctions, of earth moving, of the production of concrete, plastics and metals.

— Science Daily: Did the Anthropocene begin with the nuclear age?

Official or not, we’re certainly in it.

Welcome to the Anthropocene.

(photos from Wikimedia Commons. Click on the captions to see the originals)

• “anthropo-” = Greek for human,  “-cene” = “new” and is the ending applied to all the epochs in the current era, the Cenozoic.
• The geologic terms epoch, period and era seem to be interchangeable but epochs are short time frames, periods are next in size, and eras are the longest.  Click here for definitions.

I usually don’t chase rare birds because it often ends in disappointment.  If I don’t find the bird, the trip was wasted.  If I do find it, it’s a let-down because the bird — or my view of it — is less exciting than I anticipated.

However, at dawn on New Years Day 11 of us piled into three cars and drove to Medina County, Ohio to chase the brambling.

If you’re new to birding, you may not have heard of this slightly eccentric activity. Chasing involves lots of hurry, planning, travel, high tech communication and patient waiting.  It does not mean we approach our object closely.  If the bird feels threatened it will fly away and no one will see it so those who approach too closely are told to back off.  Humans do freak out when we’ve spent time, money and anticipation on a spectacle that another human is about to wreck!

The rarer the bird, the more people chase it.  Bramblings (Fringilla montifringilla) are exceedingly rare in Ohio so this finch has attracted hundreds of people per day.

Common in Eurasia, bramblings nest from Norway to Siberia and spend the winter in a wide swath of Africa, Europe and Asia.  Sometimes one makes a wrong turn in the fall and migrates south through our continent. Solo bramblings usually end up in northern coastal or north central states.  This adult male is the first brambling in Ohio in 28 years.

And so we made the trip.

Our group arrived just after the brambling had visited the feeder and disappeared. The parking lot was emptying. We found good standing room in the viewing area.

And we waited.  The group swelled to about 60 people.

We’d heard that the bird appeared every 30 minutes.  Not so!  At just below freezing we were not dressed for a long wait but no one wanted to leave.  After two hours the bird appeared for three minutes.

My first view was similar to this photo by Donna Foyle.  That’s how I’ll remember the brambling.  I didn’t see the clear view Shawn Collins obtained above.

Through my scope I did see the bird’s back just before the flock scattered, as in Shawn’s photo below.  The brambling is very well camouflaged on the ground.

And then the flock lifted off and he disappeared.

But I saw him!  Fortunately everyone else in our group did, too. Others who missed the bird stayed behind to wait, perhaps for another two hours.

Hundreds, maybe thousands, of birders have seen the brambling in Medina County since he was announced on December 28. Read more about his fame and discovery at Cleveland.com.

(photos by Shawn Collins and Donna Foyle)