Today's new bird is an Old World species and the largest type of pigeon or dove found in Europe: the Common Wood Pigeon!

The Common Wood Pigeon is a large species of pigeon native to parts of Europe and Asia. They are fairly common and abundant throughout their natural range. They can be found in a variety of habitats, including wild woodlands, as well as rural, suburban and urban areas.

Tomorrow's new bird will be Birdorable #700! This is our all-time most requested bird ever. Can you guess what it will be?

Did you know that some species of bird feed their chicks milk? It's true, but it's not the same kind of milk that mammal mothers feed their young.

This baby bird food is secreted from the lining of the parent bird's crop and then regurgitated to the baby birds. It is high in protein and fat as well as other components important for their growing chicks to consume, like anti-oxidants, ("good") bacteria, and substances to improve the immune system.

All species of pigeons and doves feed crop milk to their young -- for these species the substance is called pigeon milk. Flamingos also feed their young a type of milk, though production occurs in more of the upper digestive tract than just the crop. Male Emperor Penguins produce a similar substance to feed their chicks when the mother bird is away at the time of hatching.

In pigeons and doves, parent birds begin to produce the milk days before their eggs hatch. The chicks, called squabs, eat only crop milk for the first week after hatching. Afterwards other foods are introduced, after being softened inside the parent bird's crop.

What do you know about the White-winged Dove? You may have heard about the bird in the 1981 song "Edge of Seventeen" by Stevie Nicks, which you can play in the video below. In the song the back-up singers sing "ooohh baby ooohh", which is what the bird's call sounds like.

The White-winged Dove can be found in the south-west of the United states and in Mexico, Central America and the Caribbean. Lately the bird has increased its range and expanded throughout Texas and further east due to increased urbanization and backyard feeding.

White-winged Doves are amazing birds and have adapted to life in the desert. They can fly up to 25 miles to find water and are able to get their needed moisture from the saguaro cactus, which they also use for food. They are so dependent on the saguaro cactus, of which they eat the nectar, pollen, fruit and seeds, that they time their migration and nesting to match the plants fruiting time.

And when these birds migrate they can travel in very large groups. At one time flocks of up to one million birds were seen feeding in grass fields in Texas! Oooh baby, that is a lot of birds!

White-winged Dove feeding on fruit by William Herron (CC BY-SA 2.0)

Today marks the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction.

Martha as a mounted specimen, by Robert W. Shufeldt, 1921

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

We know the exact moment that the Passenger Pigeon went extinct, because the last of the species was a known captive individual named Martha. The last known individual of a species (or sub-species) is sometimes known as an endling.

Martha is not the only endling known to the world. Here are some other notable individuals that were the last of their kind.

The Tasmanian Tiger was extinct in the wild by 1930. The last captive individual died at the Hobart Zoo on September 7, 1936. Since 1996, Australia has annually commemorated the date as National Threatened Species Day.

Very recently, a Pinta Island Tortoise named Lonesome George passed away on the Galapagos Islands. He was the last of his kind, a subspecies of Galápagos Tortoise. He was thought to be at least 100 years old when he passed away on June 24, 2012.

Lonesome George 2 by Mike Weston (CC BY 2.0)

The Quagga was a subspecies of the Plains Zebra that lived in South Africa. Dutch settlement of South Africa doomed the Quagga as it was in competition for food with domestic animals. The last wild Quagga died in South Africa by 1878. The last individual Quagga on earth died at the Artis Zoo in Amsterdam on August 12, 1883.

The Carolina Parakeet is another species of bird that went extinct in North America in the early 1900s. The last known wild bird was killed in 1904, while the last captive individual, a male named Incas, died at the Cincinnati Zoo on February 21, 1918.

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

Passenger Pigeons once ranged across a wide part of eastern North America. Their preferred breeding habitat was deciduous forest; winter roosting sites were either in swamps or pine forests. Here are some more interesting facts about this species.

1) When Europeans first arrived in North America, there were an estimated 3 to 6 billion Passenger Pigeons on the continent. They were certainly the most abundant bird species in North America, and possibly the entire world.

2) Passenger Pigeons could fly 50 to 60 or more miles per hour. They had very strong breast muscles and long wings for strong flying.

3) Passing flocks of Passenger Pigeons would darken the sky and take days to pass an area.

4) Passenger Pigeons were larger than the familiar Mourning Dove. From head to tail they measured 15 to 16.5 inches long and weighed 12-14 ounces.

5) Adult Passenger Pigeons pairs would raise just one chick per year. Both parents would incubate the egg and care for the growing chick.

6) Passenger Pigeon chicks were called squabs (as are other pigeon and dove babies). Fat Passenger Pigeon squabs would fall from the nest before their first flight. The baby would remain on the ground until it was able to fly, usually a few days later.

7) Passenger Pigeons nested in huge colonies, some covering up to 850 square miles or more. A single tree may have held up to 500 nests at one time.

8) Passenger Pigeons dined primarily on nuts: acorns, chestnuts, hickory nuts, and beech nuts.

9) The term "stool pigeon" originates from the culture of hunting Passenger Pigeons. A single captured pigeon would be tied to a stool and then dropped onto the ground. Pigeons flying above the unfortunate captive would take this as a sign to land in the same spot. In this way, entire flocks could be easily captured or shot.

10) After decades of decline due to both over-hunting and rapid deforestation, the last Passenger Pigeon, an individual named Martha, died at the Cincinnati Zoo on September 1, 1914. Her exact age was unknown, but she may have been as old as 29.

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

There's no shortage of books written about Passenger Pigeons. Their journey from incredible abundance to shocking extinction is well-known. Here are just a few titles relating to Martha and her species.

This book about the Passenger Pigeon, the first new major work about the species in over 50 years, was published earlier in 2014. A Feathered River Across the Sky: The Passenger Pigeon's Flight to Extinction by Joel Greenberg tells the epic story behind the extinction of the Passenger Pigeon while drawing ties to our current relationship with the natural world.

The Passenger Pigeon by W. B. Mershon was first published in 1907. Unlike modern works, here the author gives a first-hand account of interacting with the species, its decimation at the hand of man, and its apparent impending loss.

The Passenger Pigeon by Errol Fuller is another title being released in this anniversary year. Fuller has experience writing about extinct species; he has authored books about the Dodo, the Great Auk, and other Lost Animals.

The Silent Sky: The Incredible Extinction of the Passenger Pigeon, first published in 1965, tells the extinction story in readable novel form. The book follows the life and death of the last known wild Passenger Pigeon.

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

Fold the Flock is a project to help us remember the amazing Passenger Pigeon flocks of the past. The project involves participants folding origami pigeons; their goal is to accumulate a virtual flock of one million folded pigeons by the end of the year. The flock is now just over 300,000 400,000 birds strong.

Participants can download a free PDF origami sheet to fold, or purchase origami kits containing 50 sheets. Folding a origami Passenger Pigeon is fun and easy! The PDF download has clear instructions; this animation of the folding process clearly shows all the steps.

Once you've got the hang of it, using recycled paper can make your flock colorful and unique as well as environmentally friendly. Once you've folded one or more pigeons, add your bird(s) to the flock - an online registry of all of the origami Passenger Pigeons folded by participants around the world.

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

Among other goals, Project Passenger Pigeon (PPP) was created with the aim to "familiarize as many people as possible with the history of the passenger pigeon and its extinction; raise awareness of how the issue of extinction is ecologically, culturally, and morally relevant to the 21st Century; encourage and support respectful relationships with other species; motivate people to take actions to prevent human-caused extinction, and to promote biodiversity through habitat preservation and restoration, captive breeding programs, government initiatives, and other measures."

There are a lot of educational resources and activity ideas available on the site. In order to reach as many people as possible, PPP has listed several different ideas for getting everyone involved. These include lesson plans for elementary and high school students; a shareable Powerpoint presentation; theatrical plays; a symphonic composition; and more. If you are looking for an easy activity for younger children, consider downloading our free Birdorable Passenger Pigeon coloring page.

Monday, September 1st will mark the 100 year anniversary of the death of Martha, the last of her species, the Passenger Pigeon. With her death our planet lost another species forever to extinction. This week we'd like to share some of the commemorative events and educational opportunities that are taking place to mark this important centenary.

A new documentary about Passenger Pigeons was created to coincide with this anniversary. From Billions to None: The Passenger Pigeon's Flight to Extinction follows the amazing demise of what was probably the most abundant bird species on earth. It also notes the threats facing species today and what we can do to avoid the human-driven loss of more species. Here is a long trailer for the documentary created for its fund-raising campaign.

From Billions To None is now complete and recently had its world premiere screening in Chicago. Soon the documentary will air on PBS channels across the United States. The program is scheduled to air tonight on WNPT in Nashville, and later this month on public broadcasting stations in Indianapolis, Kentucky, and Chicago. A partial list of airings can be found here; follow the From Billions to None on Facebook to learn of more airings and/or check your local listings.