Canada goose challenges the photographer (photo by David Amamoto)
Canada geese challenge their enemies by honking and rushing forward with head low, mouth open and tongue raised. Normally we humans don’t see this up close but a goose challenged David Amamoto and revealed its amazing tongue to the camera.
Since Canada geese don’t have hands, their mouths are equipped with the tools they need for plucking grasses, sedges, grains and berries on land and in the water.
Their bills are serrated for cutting stems and threshing grain. Their tongues have serrated edges for sieving water from each mouthful of underwater food. The tongue’s crosswise bumps help grip the vegetation.
Evidence that the crows roosted here (photo by Kate St.John)
As I mentioned on Monday, thousands of crows are back in Oakland roosting near the University of Pittsburgh. Though the flock is spectacular they’ll soon be unwelcome.
If your neighborhood hosts a crow roost you know about the unpleasant debris left behind by these overnight visitors. Everything is dotted with bird poop. The sidewalks are slippery in the morning and the air smells “bird-y.” This fallout is the #1 reason why crow roosts aren’t welcome near us.
When people have had enough, the crows must go. The best way to move them is by persistent audio harassment.
In November 2013 the crows caused trouble night after night near the University of Pittsburgh Student Union so Maintenance set up a loud speaker that played bird distress calls and peregrine attack sounds over and over. In five nights the crows were gone.
I have a theory that my favorite bird helped move them. Read why at:
Jet airplanes cruise at 30,000 to 40,000 feet. Did you know that birds can fly at the low end of that range?
Birds’ respiratory systems are so efficient that they can pull oxygen out of very thin air. We know this because they migrate over the Himalayas.
Common cranes (Grus grus) are widespread across Europe and Asia, nesting from Norway to Siberia and wintering from Africa to southern China. Those that nest in eastern Kazakhstan and northwestern China fly over the Himalayas to spend the winter in India. They’ve been clocked at 33,000 feet!
Bar-headed geese (Anser indicus) nest in the Tibetan highlands and spend the winter in the lowlands of India. The shortest route from Tibet to the sea is to fly directly over the Himalayas, and so they do. They’ve been recorded at 29,600 feet and seen flying over Mount Everest! This video describes how they do it and asks questions for further study.
And even mallards, the ubiquitous ducks that eat bread at the boat launch, were seen migrating at 21,000 feet over Nevada.
Birds don’t need oxygen masks at those high altitudes. They just fly by.
(photo credits: All photos are Creative Commons licensed via Flickr. Click on each image to see its original:View from a jet over the Himalayas by David C. Jones on Flickr, Common cranes in flight by Ján Svetlík on Flickr, Mallards in flight by Ken Slade on Flickr, Video from FantasticAnimal on YouTube)
You’ve probably heard the phrase “the canary in the coal mine” and know it refers to advanced warning of a danger. In the centuries before air quality instruments, miners carried canaries in cages into the mines to detect carbon monoxide and methane before they reached dangerous levels for humans.
Why did we use birds to detect bad air? Why not some other small animal?
Birds are uniquely equipped to detect (and succumb!) to bad air because their respiratory systems are so efficient. Here’s why.
Our lungs suck in air, exchange oxygen for carbon dioxide, and push it out. This is slightly inefficient because some air remains in our lungs after we exhale. If you’ve ever had “the wind knocked out of you” you know it feels awful to lose that residual air.
Birds’ lungs don’t expand and contract; they only perform the oxygen-CO2 exchange. Instead birds have 7 to 12 air sacs that act like bellows, moving air in and out of the lungs and the body. The air sacs (pink below) move air in only one direction through the lungs (dark blue below), pushing all of one breath out when the next one comes in. No residual air!
Because the air sacs perform different functions, each air molecule takes 4 steps to pass through the bird’s body –> two in/out breaths.
1st Breath, Air molecule enters the bird.
1. Inhalation: Molecule is sucked into the body by the posterior (back of the bird) air sacs 2. Exhalation: Posterior air sac pushes molecule into bird’s lungs
2nd Breath, Air molecule leaves the bird.
3. Inhalation: Molecule is pulled out of the bird’s lungs by the anterior (front) air sacs 4. Exhalation: Anterior air sac pushes molecule out of the bird!
In this way, birds have more time to absorb oxygen from each breath and their bodies notice airborne poisons sooner than mammals do.
To put it all together, here’s a four and a half minute video that shows how it works.
One more amazing feat: The thin walls of birds’ air sacs can extend into the hollow bones of their wings and legs. They have extra places to store air!
(photo credits: Click on the captions to see the originals in context. *Station Officer John Scott with canary cage used in coal mines rescue training at Cannock Chase, UK. Image courtesy of the Museum of Cannock Chase. Copyright unknown. *Bird respiratory system diagram from Wikimedia Commons. *Video of bird respiration by Ammt Bio on YouTube)
Sparrows take a sip in Bolzano, Italy (photo from Wikimedia Commons)
On Throw Back Thursday:
Like us birds drink more water in the summer heat. Have you noticed they use different drinking techniques? Some drink with faces down, others tilt their faces up.
These house sparrows appear to be using the face-down technique on a martini. But wait! The glass held ice cream and they’re picking at the remains. So what do they really do?
Find out how birds drink in this vintage article from 2010:
Gray Catbird (photo by Alan Vernon from Wikimedia)
This week gray catbirds (Dumetella carolinensis) came back to Pittsburgh from their winter homes in Central America.
I saw my first one in Schenley Park on Tuesday (April 26) and now I hear them every day, singing from the coverts in my neighborhood. Here’s what they sound like:
“Grey Catbird (Dumetella carolinensis)” from xeno-canto by Antonio Xeira. Genre: Mimidae.
“Covert” means “thicket” but it’s also an ornithological term for feathers that cover the base of the main flight or tail feathers.
Gray catbirds have rust-colored undertail coverts. Read about them in this 2010 bird anatomy lesson: Undertail Coverts.
(photo by Alan Vernon in Wikimedia Commons. Click on the image to see the original)
Imagine a group is thrown together in a new social setting and each member has to figure out where he stands. You’ve experienced this. Remember the first day of high school?
Humans work out their social hierarchy fairly quickly and quietly though, thinking back to high school, some people pick fights to establish dominance.
At first the birds had no hierarchy and quietly assessed each others’ rank without fighting. After about a week the major rankings had shaken out and some of them started to fight.
For 24 days the humans kept track of the parakeets’ interactions, carefully noting who fought and who won. Interestingly, many birds didn’t fight and even those who did seemed to pick their battles.
Analysis of more than 2,300 interactions showed that the parakeets kept track of who won and lost and extrapolated the rankings to figure out their nearest competitors and those not worth challenging. They only bothered to fight if they were close in rank and couldn’t determine it by extrapolation. For example,
Able and Charlie know they’re both stronger than Baker (no fight necessary) so they must be roughly equal but don’t know who’s best unless they fight … except …
Dirk beat up Able yesterday and Charlie beat Dirk. By inference, this makes Charlie better than Able. After only two fights the pecking order is: Charlie > Dirk > Able > Baker.
This kind extrapolation involves a lot of math (logic) and is much harder to do in large groups but the birds are so smart that they avoid fights by doing the math in their heads.
Math comes in handy, even in social settings. There’s a good reason it’s taught in high school. 😉
p.p.s. Monk parakeets (also called Quaker parakeets) are “agricultural pests” in many states. In Pennsylvania they’re illegal to own and are removed when found in the wild. This is not the case in New York where monk parakeets hang out near JFK Airport, as shown in Gintarus Baltusis’ photo below.
Monk parakeets near JFK airport (photo by Gintaras Baltusis)
Leg and foot of ruby-throated hummingbird in bander’s hand (photo by Kate St. John, bander Bob Mulvihill)
2 September 2015
Here’s the leg of a ruby-throated hummingbird, so short that the toes make up nearly half its length.
Look closely and you’ll see the foot resembles a garden claw.
Garden claw (illustration from Clipartbest.com)
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This group of birds also has tiny feet shaped like garden claws.
White-throated swifts (Crossley ID Guide for Eastern Birds via Wikimedia Commons)
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Once you know their feet are similar, it’s not a big leap to realize that these birds are related.
Swifts (Apodidae) and hummingbirds (Trochilidae) are in the same the taxonomic order Apodiformes, a Greek word that means “A”=no, “pod”=foot.
“No feet.” 🙂
p.s. Click here to read more about the similarities between hummingbirds and swifts.
(hummingbird photo by Kate St. John, garden claw clip art from clipartbest.com, white-throated swifts illustration from the Crossley ID Guide for Eastern Birds, Creative Commons license, via Wikimedia Commons. Click on the images to see the originals)
Back in July at Cunkelman’s Neighborhood Nest Watch banding, Bob Mulvihill’s mist nests captured an immature blue-winged warbler (Vermivora cyanoptera). With the bird in hand he put his fingers lightly on the bird’s beak and it immediately opened its beak and pushed Bob’s fingers away. What an unusual talent! These warblers have extremely strong gaping muscles.
Golden-winged warblers, closely related to blue-wings, are so well studied that this fact is mentioned in the literature about them. Bob has also found it to be true of the (formerly*) Vermivora warblers and oriole species he’s banded in eastern North America.
Why this unusual talent? Vermivora literally means “worm eater” — vermi:worm, vora:eat. The “worms” are small caterpillars (not earthworms) that hide among leaves, often wrapped in cocoons or in curled up leaves. The warblers open the rolled leaves against the caterpillars’ will.
When you see these talented birds watch them probing among the leaves. They’re making a strong opening.
(photo by Kate St. John)
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And what’s all this about formerly(*)?
The genus Vermivora used to contain nine species including Tennessee, orange-crowned, Nashville, Virginia’s, Colima and Lucy’s warblers, but in 2010 the American Ornithological Union transferred all but Bachman’s (extinct), blue-winged and golden-winged to the genus Oreothlypis. After years of having nine Vermivoras, it’s hard to keep up with the changes.
