I believe I know the answer but I’m not absolutely sure so I’m asking you, dear readers.
What tree is this with such bountiful fruit? It’s a short, ornamental tree, probably non-native. Notice how the bright red fruit hangs in clusters from the branches. I’m amazed the birds were not eating it yet.
Want to see it for yourself? It’s one of several such trees in Schenley Park on the right side of the walk to the ice rink near Schenley Oval.
If you know its name – or even have a wild guess – leave a comment to let us know.
Human faces turn red with anger or embarassment and pale with fear. Do other animals do that?
Well, yes. Some vultures can rapidly change the skin color of their bare faces and throats in response to peers and rivals. Scientists in Namibia observed interactions among lappet-faced vultures at feeding sites and found that these birds have their own “vulture facebook” signals.
The scientists learned that lappet-faced vultures with pale skin are at the bottom of the pecking order, even lower than juveniles. Those with bright red skin, as seen on the throat of the vulture pictured here, are dominant over pale-skinned and juvenile birds and vultures with blue throats were dominant over all.
This knowledge adds a whole new dimension to vulture watching.
Do our turkey vultures do this?
I don’t know. Maybe they don’t use (vulture) Facebook.
(photo linked from Science Daily, credit: iStockphoto/Johan Swanepoel. Click on the photo to read the Science Daily article.)
Gray squirrels are, of course, gray — that’s how they got their name — but did you ever notice that in the summer they’re actually rather brown?
From March through June gray squirrels molt into a brown or tawny pelage that blends well with their summertime surroundings. Then in September and October they molt again, this time into paler, grayer winter coats so they’re ready when the cold winds blow. My backyard squirrels are making this change but their faces and ears are still brown.
Lately I’ve seen the squirrels on frequent caching expeditions up and down the street because my neighbor has a prolific black walnut tree. I’m sure the squirrels are burying walnuts but I only see evidence that they’re eating them. They leave behind little piles of broken shells and a permanent black stain on the cement.
I wish they wouldn’t pick my front steps for their walnut feasts but I can understand their urgency.
Winter’s coming. It’s enough to turn a squirrel’s hair gray.
(photo from Wikimedia Commons. Click the photo to see the original.)
I think the colors are subdued this fall because we’ve had a drought. Even so I saw some nice red leaves on Thursday evening in Schenley Park. It’s not a good picture but you get the idea.
And… the crows are back! Last night I saw more than 300 flying to the roost. This morning I counted about 1,000 flying southwest over my neighborhood.
I thought my blog’s anatomy series was nearly over because I was running out of material. Then last night Chuck Tague presented an excellent program at the Wissahickon Nature Club on how bird anatomy is adapted for flight. Now I’m inspired.
What most impressed me is that birds have the same basic internal equipment that we do — lungs, backbone, arms, toes, etc. — but the location, proportions and shapes of their body parts are altered because they fly.
For instance, human heads can afford to be heavy (and they are!) because we walk upright and easily balance our heads at the top of our bodies. Birds’ heads cannot be heavy unless something equally heavy balances them horizontally at the other end. Their solution is to have lightweight heads and alter the shape of their bodies to change the weight distribution.
Which leads me to the keeled sternum or breastbone. It provides the anchor for the flight muscles. Notice that it’s huge and sticks out! When a bird flies its keel is positioned in the air the same way a boat’s keel is positioned in the water — one of many reasons why the sternum takes this shape.
If humans had keeled breastbones we’d tip over as we walk. Instead our sternum is flat and positioned vertically.
There are a few birds who don’t have keeled breastbones and they are… can you guess?… birds that don’t fly. Ostriches, emus, cassowaries, rheas and kiwis all have flat sternums. A keel would get in their way and possibly throw them off balance as they walk. Their unusual sternum (for a bird) gave their group a name. Ratites means “raft-like sternum.”
(photo from Wikimedia Commons. Click on the photo to see the original.)
When I read the bird reports from eastern Pennsylvania I’m always a little jealous because they have such a wide variety of birds over there.
It’s unusual to see a species in western Pennsylvania that’s not common in the east as well. Rusty blackbirds are an exception to that rule.
Rusty blackbirds (Euphagus carolinus) breed in Alaska and across Canada in wooded swamps and willow thickets. No matter where they are, they prefer to keep their feet wet which means that glaciated, swampy, northwestern Pennsylvania is a great place to find them on migration.
Last Sunday I visited Glade Dam Lake in Butler County where a lot of the area is marked “subject to inundation” on the map. In other words, it’s a swamp ideal for rusty blackbirds — and they were there.
Because rusty blackbirds are declining and sometimes rare I’m always careful to get a good look at them before I get excited. Distant backlit flocks are difficult to identify in flight because they’re the same size as red-winged blackbirds. Up close they’re easy. Though they’re black in the breeding season they become rust-colored in the fall and their yellow eyes stand out. Even their voice is rusty, a noise that resembles a creaking rusty gate.
At Glade Dam Lake I heard their voices but couldn’t see them in the swampy woods until the flock grazed its way to the parking lot. Ta dah! Rusties!
Steve Gosser had a better view of them at Mosquito Lake, Ohio on October 14. That’s where he took this picture and a video of rusty blackbirds doing their favorite thing: keeping their feet wet.
We had a little peregrine excitement at the University of Pittsburgh yesterday.
Around 3:00pm Tony Bledsoe called to tell me that he was outdoors by the Cathedral of Learning and he could hear our peregrines chirping-cacking.
It’s unusual for them to make noise in the fall. As we remarked on this over the phone Tony saw why they were making noise. “There are three peregrines. They’re chasing each other! This might be a fight.”
Indeed a third peregrine had arrived on campus and the two residents were chasing him away. Tony saw a lot of chasing but nothing dangerous. Eventually two of the birds — both males — flew off to the south. Dorothy stayed at home to await further developments.
At 3:15pm I took my binoculars to the west window at WQED and tried to find the peregrines on the Cathedral of Learning. One of them was perched at the southeast 38th floor corner, E2’s favorite spot. As I watched he took off and flew toward me, pumping hard to chase a bird I couldn’t see to my east. Whoever it was got the message and left. E2 banked above Central Catholic and returned home. Within a minute both he and Dorothy were prominently perched atop the Cathedral of Learning, warning all other peregrines to stay away.
Later Dorothy stopped by the nestbox, scuffed at the gravel, and perched at the lookout. Waiting and watching.
October’s the time when arctic peregrines migrate through Pittsburgh and the mid-latitude falcons wander to find a territory. Dorothy and E2 are vigilant this month, defending the home front. They have no intention of losing their territory.
(photo from the National Aviary snapshot camera at the University of Pittsburgh)
On South Padre Island, Texas, peregrine falcons are helping scientists study the effects of BP’s Gulf oil spill.
Because peregrines are at the top of the food chain they’re a good indicator species for threats to the environment. Their population crash in the 1960’s showed us the dangers of DDT. Now they’ll tell us if BP’s oil spill has made its way into the food chain.
To do this, a team from The Peregrine Fund is taking blood samples from migrating peregrines who stopover at the Gulf of Mexico on their way to South America. While on South Padre visiting arctic peregrines eat birds, some of which may have been affected by the oil spill. Are there traces of oil in the peregrines’ blood? If so, the spill is having long-lasting effects.
The peregrines aren’t exactly willing participants in the study — they must be captured to get a sample — but their moment for science is brief and then they’re on their way.
As of last night, Pittsburgh’s huge winter flock of crows had not arrived yet but I expect them any day now. In the meantime I’ve been learning more about crows, and you can too.
Coming this Sunday, October 24, at 8:00pm on PBS’s Nature is an excellent program on crow intelligence called A Murder of Crows.
Crows have been watching us for a very, very long time but it’s only recently that scientists have begun to watch back. Here’s what they’ve found out. Did you know that…
Crows watch us more than we watch them.
Crows can recognize the faces of people who’ve hurt them.
Crows teach each other which people are dangerous so the entire flock knows who to avoid.
Crows probably got a bad reputation because we know they’re a lot like us (intelligent and social), but crows will do the things that humans will do that we aren’t particularly proud of.
This is just a taste of what you’ll learn from A Murder of Crows this Sunday, October 24 at 8:00pm on PBS.
In Pittsburgh, it’s on WQED. Perhaps our crows will arrive in time to see it.
p.s. A “murder of crows” is a flock. As the show opens there’s a very good black and white animation of a crow flock that is frankly rather scary. Even I, who love crows, found it disturbing but it was the only disturbing image in an otherwise upbeat and fascinating program.
If you didn’t have dark-eyed juncos in your neighborhood all summer, don’t worry they’re on their way.
Juncos breed in Canada and the mountainous parts of the United States. In October and November they move south or to lower elevations, but not far because they prefer cool climates. Some of them spend the winter in Pittsburgh.
I’m looking forward to their arrival in Schenley Park because “I like their clean little coveralls” (as William Stafford said in his poem Juncos).
