Last Sunday in Schenley Park I found these small hard berries littering the trails ... and then one fell on my head. I looked up to see a flock of robins knocking berries to the ground as they reached to eat them.
It's easy to identify the berries by the bark of their tree. The common hackberry (Celtis occidentalis) has distinctive layered ridges.
Here's a closeup of one ridge, photographed on a frosty morning.
Birds eat the berries. Deer eat the twigs.
Hackberry trees provide lots of food for wildlife.
The black silhouettes in this tree near the Cathedral of Learning are not leaves. They're crows.
Pittsburgh's crow population has swelled since the weather turned cold last weekend. On Monday I counted 4,000 flying into Oakland from the south, pausing on the roof of Carnegie Museum before heading to their final destination.
I couldn't even see the crows arriving from east, west and north but distant trees at Schenley Farms were coated with crows and hundreds, perhaps thousands, gathered on the rooftops north of Fifth Avenue. My cellphone barely captured a look at them as night was falling.
Where did they roost? I didn't stay long enough to find out, but they left their evidence behind.
On Tuesday Claire Staples sent me photos from St. Paul's Cathedral on Fifth Avenue. The crows left a mess on the wall and sidewalk below the stately London plane trees.
For now the crows are roosting near Fifth Ave and Craig Street but that will change. They're wearing out their welcome.
There are six falcons native to North America -- gyrfalcon, peregrine, prairie falcon, aplomado falcon, merlin and American kestrel -- but back in 2010 I had seen only four of them because I hadn't traveled west or south to the places that prairie and aplomado falcons call home.
That year I didn't need to leave Pennsylvania to find a prairie falcon. Since 2005 a single bird had spent the winter near Mud Level Road in Cumberland County. In November 2010 I decided it was time to chase that Life Bird.
Prairie falcons (Falco mexicanus) range in North America from the Great Plains westward to the Pacific coast. They move in spring and winter but normally travel north-south or up-slope/down-slope. Pennsylvania is not only wetter than their usual habitat but is very far away. The purple squares below show where they were reported on eBird, 2015-2017. The darkest purple is their most frequent location.
When a prairie falcon was first noticed at Mud Level Road in late fall 2005, birders assumed it was an escaped falconer's bird though it showed no signs of a former life, no jesses, no radio tracking antenna. They soon found out it roosted overnight at a nearby quarry. Then year after year the bird came back in November and left in early spring, obviously migrating. From the winter of 2005-2006 through the winter of 2013-2014 he returned for eight more years.
Like the peregrines I can identify as individuals because they're the only two on territory at Pitt, this prairie falcon was unique because of his location. He was not just any falcon. He was the prairie falcon.
The bloom reaches it peak in autumn. You can see the green muck from outer space in this satellite photo from September.
These algal blooms are triggered by warm water containing excessive nutrients: nitrogen from sewage and/or phosphates from fertilizer. In this century the water is warmer and it contains a lot of phosphorus flushed into the lake by heavy rain. Cleveland.com explains that "The Maumee River contributes half of all phosphorus in the lake, with about 85 percent of it from fertilizer runoff." (The Maumee enters the lake at Toldeo.)
We know how to fix this problem. We've done it before.
Back in 1969 Lake Erie was plagued by pollution, toxic algal blooms and dead fish. One of its tributaries, the Cuyahoga River, caught fire in Cleveland. Thanks to the Clean Water Act and the EPA established by President Nixon, Lake Erie was cleaned up quickly and stayed that way for 30 years.
Thirty years ago Japanese trains had a problem. They could travel fast but they caused sonic booms.
The answer was the bullet train. How did Japanese engineers develop it? They learned from birds.
Watch this 6+ minute video from Vox + 99% Invisible to learn how birds showed the way and follow one woman's quest to teach engineers that Nature has the answers. Our world can benefit from biomimicry.
For best results, copy birds.
Thank you to Holly Hickling for sharing this. For more cool videos, follow Vox (news site) or 99% Invisible (city design updates) on Facebook.
You know things are strange when there's an outbreak of 15 tornadoes in Ohio and western Pennsylvania in November.
Just over a week ago, on Sunday November 5, 2017, a cold front passed over the southern Great Lakes and Ohio River Valley. Before the front arrived it was humid and around 70 degrees -- as much as 17 degrees above normal -- so the front's leading edge spawned 15 tornadoes.
The National Weather Service in Cleveland mapped 14 of them in their region. I've added the EF-1 tornado in Calcutta, Ohio just west of Beaver County, PA reported by the National Weather Service in Pittsburgh. Yes, 15 tornadoes!
The tornado in Williamsfield, Ashtabula County, Ohio was one of the strongest, an EF-2 with winds of 127 miles per hour. It cut a swath 7 miles long ending at the western shore of Pymatuning Lake. The damaged house shown above makes me glad I wasn't there!
This [Calcutta, Ohio tornado] is the 14th confirmed tornado so far this year in our county warning area. On average, we see five tornadoes a year. This is the first November tornado since 2003 /14 years/ in New Philadelphia, Ohio. This is the 5th tornado in November for Columbiana county since 1950.
Experts say that climate change increases the frequency of severe weather. I'd say that 15 tornadoes in November look like a good example.
In autumn ginkgo trees (Ginkgo biloba) turn bright yellow and can lose all their leaves in as little as one day.
Yesterday morning I saw these ginkgos "snowing" so I stopped to film them (11 seconds). The scene is so bright that it's hard to see individual falling leaves ... but there are many.
I returned six hours later to see if the trees were bare. Not yet, but close.
Here's the before and after.
Before: 11 November 2017, 10:30am
After: 11 November 2017, 4:30pm:
If you want to see ginkgos make a carpet of leaves, I know of two places to go: Schenley Drive near Phipps Conservatory and Highland Avenue near the entrance to Highland Park. But watch them soon. They may be bare by the end of the day.
His new book shows how our view of birds has changed over time -- from objects of worship, food sources, ornamentation, sport, and status symbols to beautiful creatures we watch in the wild. His stories of collectors, breeders, watchers, scientists and conservationists are illustrated with rare and stunning artwork inspired by (our!) obsession.
Helen Macdonald, author of H Is for Hawk says of the book, "An exquisitely beautiful book ... These stories about birds are ultimately reflections on the curious nature of humanity itself."
What: Bernd Brunner, author of Birdmania, at Pittsburgh Arts & Lectures. A book signing will follow the lecture. Tickets $5. Where: Carnegie Library Lecture Hall, 4400 Forbes Avenue, Pittsburgh, 15213. When: Saturday November 18, 2017 at 2pm.
This week's cold weather bought winds from the north and flocks of tundra swans over western Pennsylvania. We usually hear them first, rush out to see them fly ... and then they're gone.
Where did they come from? Where are they going?
Most of "our" tundra swans breed in the north central territory of Canada (Nunavut) and north of Hudson Bay. This map from Xeno Canto shows their path in North America. (Breeding range is pink. Migration corridors are greenish yellow. Wintering sites are blue. I've added a purple dot for our location in western Pennsylvania.)
In late September tundra swan families assemble into flocks. Then "our" swans move south through Canada's prairies, arriving in North Dakota and the upper Mississippi River valley in early October where they eat and wait until winter hits.
On winter's first blast they fly southeast to Chesapeake Bay and eastern North Carolina, passing over Pennsylvania on their way.
Tundra swans typically fly 30 miles per hour but on a strong northwest wind they can clock 100 mph and fly non-stop for 1,000 miles.
Most flocks don't stop in western Pennsylvania but they take a break here if the "kids" get tired. That's what happened on Tuesday at Crooked Creek Lake.
Marge Van Tassel and a group of volunteers heard the swans coming and drove to a good vantage point to watch them come in. Marge's photo shows them descending to the lake like large beautiful snowflakes.
Listen for their sound overhead and you may see tundra swans, too.