Little auks (Alle alle) at Svalbard breeding colony (photo from Wikimedia Commons)
Here’s amazing news: Seabird colonies help keep the Arctic cool.
Seabirds gather on Arctic islands to breed during the summer. Thousands of them nest close together and produce a lot of guano (bird poop).
Atmospheric scientists studying the Arctic noticed summertime bursts of ammonia-based particulate. These tiny particles cause clouds to form because they gather moisture as they move through the air. The clouds reflect sunlight and keep the land and water cool.
Where does the ammonia come from? It wafts off the guano at the seabird colonies.
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 shows how they do it.
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)
John Scott holding a canary cage used in coal mines rescue training at Cannock Chase, UK (Image courtesy of the Museum of Cannock Chase. Copyright unknown.)
Today, a bird anatomy lesson.
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.
Human lungs and diaphragm (animation from BIO 378, Prof. Gary Ritchison, Eastern Kentucky University)
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!
Bird respiratory system, air sacs highlighted (image from Wikimedia Commons)
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 each image to see its original 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.
*Human lungs and diaphragm. Image linked from Bio 378, Lecture 10, Prof. Gary Ritchison, Eastern Kentucky University
*Bird respiratory system diagram from Wikimedia Commons.
*Video of bird respiration by Ammt Bio on YouTube)