BirdNote

When a Carolina Wren like this one sings, something remarkable happens. These birds can sing so loudly that you almost have to shout to be heard over their songs!

Why are some creatures rare and others common? What forces – natural and manmade – cause rarity? Eric Dinerstein of the World Wildlife Fund travels far and wide for answers. He wonders how different the world could be with a few changes: “. . .

Who among us hasn’t almost walked into a glass door? Birds though, especially when migrating, run the risk of colliding with reflective glass in urban areas.

When a Canyon Wren sings, the brilliance of its sweet music can stop you in your tracks. But when its cousin, the Marsh Wren (seen here), sings, you may reach for your earplugs. Why do two closely related birds sing such contrasting songs?

Heidi Hoelting, a musician, listens carefully to the songs of birds. In her piano studio at her home in the woods, she wrote down several variations of the different sounds a Song Sparrow makes. In this BirdNote, Nancy Rumbel plays some of those variations on a bamboo whistle.

Seabirds have no problem drinking sea water. The salt they take in is absorbed and moves through their blood stream into a pair of salt glands above their eyes. The densely salty fluid is excreted from the nostrils and runs down grooves in the bill.

Rock Pigeons are one of the most common urban birds. But why do we never see baby pigeons? Some baby birds - like down-covered ducks, geese, and chickens - leave their nest shortly after hatching and do a lot of growing up while following their parents around.

As the sun sets on a northern Midwest forest, an American Woodcock walks slowly from the cover of the forest to a nearby clearing. Then, the woodcock takes off on a courtship flight.

In January 2009, a US Airways flight completely lost power after striking a flock of Canada Geese. The captain was able to guide the crippled plane to an emergency landing in the Hudson River, and all passengers were safe. Protecting planes is a constant challenge.

Sitting on a piling, wings outstretched, the Double-crested Cormorant looks like a black Celtic cross. Cormorants dive from the water's surface, pursuing prey under water, propelled by powerful webbed feet.

April 1, 2013 - High above the clouds caressing the upper reaches of the mountains soars the most majestic bird you are never likely to see or hear: the Semi-Fixed-Wing Silver Delirian.

Inspired by a talented friend's painting called "Ballet of the Unhatched Chicks," Russian composer Modest Mussorgsky wrote a piano piece as part of his famous work Pictures at an Exhibition. The composition was later orchestrated by Maurice Ravel.

The soft whistles of this Great Tit, a common European bird, can be hard to hear over city noises. So these birds now sing at a higher pitch and faster than normal. This song carries better over the traffic noise of the city.

Darvin Gebhart is a champion goose-caller. But there are also birds that use human language. Sparkie Williams was a famous parakeet, or budgerigar, that lived in England in the 1950s.

Every spring, Great Blue Herons build sprawling nests high in trees, in colonies. The male heron finds and brings the sticks, and the female decides what goes where. Learn more about herons at Cornell's All About Birds. During nesting season, view a heron cam.