27 December 2024
White-fronted nunbirds (Monasa morphoeus) are at their most interesting when they sing in “group choruses of loud gobbling, barking notes, sustained for up to 20 minutes at a time, chiefly at the beginning and end of day.” — quoted from Birds of the World.
If you wanted to hear them in the wild, go to these regions of Central and South America.
p.s. “White-fronted” describes birds whose foreheads are white such as the greater white-fronted goose and white-fronted nunbirds.
24 December 2024
A family in Arlington, Virginia was surprised this week by a live Christmas ornament on top of their tree.
A barred owl came down the chimney, found itself indoors and perched on a familiar object. The Christmas Owl.
16 December 2024
This giant shark snout in the sky is a flock of thousands of common starlings (Sturnus vulgaris) flying at dusk near Gretna, Scotland. As starlings gather to roost their tight flocks, called murmurations, wheel and turn in unison making beautiful patterns in the sky.
Sometimes the flock makes a recognizable shape like the hawk-bird in this video. They aren’t trying to do this. It just happens. Wow!
(video embedded from Stuart McNeil on YouTube)
Under pressure from a predator, starlings intentionally fly closer together and shape-shift into giant blobs, making it impossible for the predator to lock on to a single bird as prey.
Can you see the peregrine at top right, above, and to the left below?
The only way for a peregrine to catch dinner is to break the blob. He rushes the flock, trying to separate a few starlings away from the group. The blob gets even tighter!
Watch a peregrine shape-shift the starlings and ignite the magic in a murmuration.
5 December 2024
Crows are so vocal that we can’t help but think their caws are a language. So what are crows saying in their big boisterous flocks before they roost?
Dr. Douglas Wacker at University of Washington Bothell (UWB) wondered the same thing so in 2017 his team began recording and analyzing pre-roost aggregations on the UWB roofs. The rooftop recordings were not enough to crack the code so now the team has turned to spectrogram analysis.
Dr. Wacker presented information on crow vocalizations at the Olympic Peninsula Audubon Society in November 2024. To measure the calls they analyzed these components.
The team recorded crow vocalizations in various contexts and compared the spectrograms. And they discovered an unusual thing. Crows appear to be “saying” things in the silence between their caws (gaps) and the pauses between their calls.
If you want to know what a crow is saying, listen to their silences.
Learn more about crow language in this Olympic Peninsula Audubon Society’s video. I have set it to start nearly an hour into the meeting, beginning with spectrogram analysis of crow calls. I’ve included this 15 minute portion here because it is so interesting. Click here to see the entire 1.5 hour meeting.
Some day we might know what this crow is saying. In the meantime, listen to the gaps.
p.s. Dr. Wacker described an intriguing idea: The messages in human language come from our sounds. The messages in crow language appear to come from silences. Perhaps we can’t figure out what crows are saying because we aren’t used to listening to the silences.
6 December 2024
Since late October visiting crows have been pouring into town to join Pittsburgh’s enormous winter crow flock. Their numbers in Shadyside and Oakland grew from 3,600 in mid-October to over 8,000 in mid-November … and then I lost track of them because they moved the roost and changed their flight path.
Alas! The flock is still growing — perhaps to 20,000! — and just three weeks from now on Sat. 28 December will be the annual Pittsburgh Christmas Bird Count (CBC) when we’ll confirm the number of crows that come to town for the winter. If we can find them.
I had hopes last Saturday 30 November when Betty Rowland saw a huge flock staging at Schenley Park’s golf course, photo above. But when Betty checked again on Monday the crows were completely gone.
Our winter crows change or split their roost often in late December because they wear out their welcome so quickly. (See examples here.) So where are they now?
Please help. Let me know where you see lots of crows just before sunset or at night in the city and/or Allegheny County. Tell me about …
Your sightings are especially important in the week before the CBC, December 22-27.
To get you in the mood, here’s a video from Winter Crow Roost in Lawrence, Massachusetts where they’ve ramped up crow counting with photography and videos. Woo hoo!
For more about counting crows in Lawrence, MA see their website at Winter Crow Roost.
4 December 2024
In just 17 days the winter solstice on 21 December will bring us the shortest day and longest night. Since peregrines cue on the amount of daylight to trigger their breeding season, they aren’t in the mood for courtship right now. But the Pitt peregrines stay at the Cathedral of Learning year round and occasionally visit the nest ledge anyway in the off season. Sometimes they call for their mate to join them in a bowing session.
In the snapshot above Ecco calls for Carla to join him last week. “Hey, Carla. Come here!” She didn’t show up then, but she stopped by on Sunday. However Ecco didn’t arrive. (Note: The sun’s low angle made white dirt-spots glow on the camera housing.)
Finally on Monday Ecco and Carla met at the ledge (slideshow from the National Aviary snapshot camera).
2 December 2024
How do birds avoid midair collisions? In 2016 scientists learned that budgerigars flying head on toward each other avoid crashes by always turning right.
Researchers in Australia trained 14 male budgies to fly in a narrow well lit tunnel, one at a time. After the birds were acclimated they positioned one bird at each end of the tunnel and let them fly straight at each other. Two set of cameras recorded the birds’ reactions.
Over the course of four days, seven budgie pairs made 102 flights with no mishaps. When the researchers reviewed the video, they saw that the birds avoided any aerial mishaps thanks to two evolutionary traits. About 85 percent of the time, the birds turned right upon approach. “This seems to be a simple, efficient and effective strategy for avoiding head-on collisions,” Srinivasan said.
The budgies also seemed to decide whether to fly over or under an approaching bird, and the pairs rarely made the same choice. … The researchers speculate that either each budgie prefers one flying height over the other, or flock hierarchy determines who flies high and who flies low.
— Audubon Magazine: Birds Avoid Mid-Air Collisions By Following These Two Simple Rules
Here’s what the tests looked like.
We use the same principle in traffic. “Stay on the right.”
Well, actually, 70% of the world drives on the right, 30% on the left. Heaven help you when you drive in a country that does the opposite of what you’ve learned!
Fortunately budgies always use the same rule.
1 December 2024
White-breasted nuthatches (Sitta carolinensis) are small but spunky. When they have a good spot at the feeder they defend it by puffing up.
Sometimes it’s just a mild warning like this tail-fanning to a house sparrow.
Sometimes it’s an open wing display like this one to a tufted titmouse.
And if it’s really important the nuthatch opens its wings and sways side to side in a mesmerizing display. The bluebird on the other side of this feeder stares for a while and decides not to stick around.
I’ve never seen this swaying threat display but I learned about it in BirdNote’s podcast: Nuthatches Sweeping the Nest after they described another unusual nuthatch behavior.
Did you know that white-breasted nuthatches use crushed bugs and other items to lay scent outside the entrance to their nests? Listen to BirdNote to find out more …
… and then watch a nuthatch sweep a bug around its nest hole.
Now that winter is really here, fill your feeders and wait to see a nuthatch tell the other birds, “I’m warning you!”
29 November 2024
Now that Thanksgiving is over turkeys can own the road again.
It’s been a long time since I’ve seen a wild turkey cross the road in the City of Pittsburgh. Six years ago they were very common in Pittsburgh’s East End but there are gone now, perhaps because the City’s huge deer population eats all their winter food.
If you want to see a lot of turkeys visit Pittsburgh’s northern suburbs. In February I saw 20 cross the road near North Park.
Fortunately none of them wanted to challenge cars!
20 November 2024
The number of crows in the East End increased recently after they began roosting at Pitt again. On Saturday night I saw hundreds of crows in the trees at Carnegie Library and the Cathedral of Learning so on Monday afternoon I did a walk-about to count “crow trees” that showed evidence of roosting. (A big tree holds 250 crows.)
My tree count was way too high so on my way home I paused at Fifth and Craig to count the huge flock passing overhead on their way to Pitt. 8,000 to 8,500 crows.
On Tuesday evening I could see crows staging in the trees above Morewood Ave so I counted again. 8,000 crows. … And this is just the East End flock.
The crows may be wondering why I’m counting(*), but crows can count too though not so high. A study of carrion crows (Corvus corone), published in Science last May, showed that this Eurasian equivalent of the American crow can count up to 4 out loud, similar to human toddlers.
Three carrion crows were trained to vocalize with one, two, three, or four caws depending on the number they saw in front of them. They were also taught to tap the screen when they were done counting.
The birds boasted a 100 percent accuracy rate at counting to one, a roughly 60 percent success rate at counting to two and about a 50 percent accuracy rate for three.
Crows particularly “disliked” the number four (40 percent accuracy), sometimes refusing to caw at all when prompted and pecking at the screen to end the trial immediately, [according to] study co-author Diana Liao, an animal physiologist at the University of Tübingen.
Additionally, the crows paused before cawing correctly, showing longer reaction times before producing higher totals of vocalizations. This delay is consistent with mental planning.
— SMithsonian Magazine: Crows Can ‘Count’ Up to Four Like Human Toddlers, Study Suggests
The test reminds me of a story Chuck Tague told me many years ago. He and his wife Joan visited a bird blind to see an elusive bird that would not come out if a crow was watching. Unfortunately whenever he and Joan went to the blind a crow would follow them and wait for them to leave.
They decided to fool the crow. Both of them went into the blind but only Chuck came out. Surely the crow would leave and Joan would see that elusive bird. Nope. The crow counted two people going in and only one came out. They changed it up and Joan came out but it made no difference. The crow could certainly count two people.
Maybe I’ll have a chance to try this some day. Meanwhile, read more about the study in Audubon Magazine: Crows Can Count Aloud Much Like Toddlers, New Study Finds.
(*) p.s. I’m counting crows to get in practice for the Pittsburgh Christmas Bird Count on 28 December 2024, the Saturday after Christmas. Last year we counted 15,000!
