Gouldian finches (Erythrura gouldiae) are colorful Australian seed-eating birds that nest in tree holes in the wild or in nest boxes when bred in captivity. Their nests are always dark inside so the nestlings have unusual mouth markings to attract their parents’ attention. Each nestling has:

• Four opalescent tubercles at the corners of the gape that reflect a bluish light.
• Patterns inside the mouth that guide toward the gullet.

Words cannot describe Gouldian finch chicks! Thanks @SaveTheGouldian, gorgeous pic of a wild Gouldian nestling pic.twitter.com/MaFQUEqTkM

— Aus Bird Study Assoc (@ABSAbirds) June 30, 2015

To further attract attention, the nestlings hold up their mouths and rotate their heads as shown in this video of 3-day-old chicks.

The nestlings’ elaborate show may have evolved because …

Gouldians are among the most difficult finches to breed successfully because they are not wonderful parents and have a tendency to abandon both eggs and babies, or even refuse to nest at all. People who raise Gouldians usually keep society finches as well to serve as foster parents for eggs and babies. Societies are marvelous parents and will be happy to foster other species. 

— Gouldian finch description at Lafeber website

The babies that survive are the ones with beckoning beaks.

(photos from Wikimedia Commons and embedded from Twitter; click on the captions to see the originals)

p.s. See more examples of weird baby bird mouths at Audubon Magazine’s What’s Up With the Weird Mouths of These Finch Chicks?

When we find a feather we often wonder, “What bird dropped this feather? What species is this?” Here are some quick tips for identifying feathers.

Before we begin, keep in mind that without a permit it is illegal to collect and/or keep feathers of any native non-game species. You can touch feathers, flip them over, and take lots of photos but you must leave the feathers behind.

Photos are what you really need anyway. Include an object near the feather to give it a sense of scale (size). Remember the location and habitat where you found it so you know what species are possible. Now you’re ready to figure out whose feather it is.

First determine the feather type so you know where it came from on the bird’s body. At this point you don’t care about color.

In the wild you’re most likely to find tail, wing or contour feathers, the same ones you see on the bird. The descriptions below include parts of a feather vocabulary defined here.

• Rectrix (tail): Tail feathers (plural:rectrices) have barbs of equal length on both sides of the vane. (red arrows)
• Remige (wing): Wing feathers have short barbs on one side, long ones on the other. (yellow arrows short and long)
• Contour feather: covers the body
• Semiplume: insulation under the contour feathers
• Down: the warmest insulation near the skin
• Bristle: sensory vane near beak and eyes (unlikely to find)
• Fitoplume: sensory vane on wings (unlikely to find)

Next, think of birds with colors and patterns at that location on the body.

For additional help use the U.S. Fish and Wildlife Feather Atlas ID Tool for North American birds. At the Feather Atlas you’ll need to know the feather’s size in centimeters before you begin.

Ready for a quiz?

A. The feathers shown above are from a great spotted woodpecker eaten by a predator in Germany. What body part did they come from?

B. Here are two feathers of North American backyard birds. It’s a little harder to tell what body part they came from. (Length: red=9-10cm, blue=12-14cm) What do you think? Can you identify the species?

It’s challenging to identify feathers. Here are more resources to help.

• USFW Feather Atlas,
• David Sibley’s tips for identifying found feathers,
• Birdwatchers’ Digest Six Different Feather Types.

(photos from Wikimedia Commons; click on the captions to see the originals)

When we think of birds we take feathers for granted. But what do we really know?

How do feathers grow? What holds them on the bird? How are feathers replaced? Do feathers have nerves in them? How do they become curved?

On Throw Back Thursday, find the answers in this vintage article: Feather Facts.

(photo from Wikimedia Commons; click on the caption to see the original)

Why do so many soaring birds and seabirds have white wings with black tips? For starters, black plumes are more durable than white ones, providing an advantage at the tips. New research this summer shows another possibility.

A study at the University of Ghent determined that the black-and-white color combination generates extra lift because of the temperature difference between the colors.

Using taxidermied wings, a heat lamp and a wind tunnel, the researchers measured airflow over the wings in a variety of wind conditions. They found that:

… dark feathers grew hotter than lighter colored feathers and they also gained heat faster than lighter colors. The researchers found temperature differences as great as nine degrees between black and white feathers on the same wings—enough to create a convection current in the air just over the wing, moving from the bird’s body outward along the wing.

— from Study suggests dark-colored wing feathers may help birds fly more efficiently, phys.org

The study described a convection current that works like this.

American white pelicans and northern gannets both benefit from this additional lift.

So does the osprey because he’s black and white beneath his wings.

How ingenious!

Black wingtips help them soar.

(pelican and gannet photos from Wikimedia Commons; osprey photo by Dana Nesiti)