What Is a Bird?
Everyone knows what birds are – even the smallest child can tell the difference between a bird and, well, a non-bird! But what distinctive features are exclusive to birds? Is it the presence of wings, feathers, or the ability to fly? Is it the ability to lay eggs? Is it the presence of a beak and lack of teeth?
All of these features are found in birds. Birds can be described as warm-blooded vertebrate animals that have wings, feathers, a beak, and no teeth; a skeleton in which many bones are fused together or are absent; and an extremely efficient, one-way breathing system.
Check Your Thinking: If you were to pick just one feature however that is unique to birds and ONLY to birds, and is present in all birds, what would it be?
Before we delve further into the science of birds, let’s look at some of the amazing shapes and sizes of birds from around the world.
Central and South American Birds
![andeancock Figure 6.2: Andean Cock-of-the-Rock. Image from URL: http://en.wikipedia.org/wiki/File:Rupicola_peruviana_(male)_-San_Diego_Zoo-8a.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/andeancock.jpg)
Figure 6.2: Andean Cock-of-the-Rock.
Image from URL: http://en.wikipedia.org/wiki/File:Rupicola_peruviana_(male)_-San_Diego_Zoo-8a.jpg
![harpyeagle Figure 6.3: American Harpy Eagle. Image from URL: http://en.wikipedia.org/wiki/File:Harpia_harpyja_001_800.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/harpyeagle.jpg)
Figure 6.3: American Harpy Eagle.
Image from URL: http://en.wikipedia.org/wiki/File:Harpia_harpyja_001_800.jpg
![swordhumming Figure 6.4: Sword-billed Hummingbird. Image from URL: http://en.wikipedia.org/wiki/File:Sword-billed_Hummingbird_(Ensifera_ensifera).jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/swordhumming.jpg)
Figure 6.4: Sword-billed Hummingbird.
Image from URL: http://en.wikipedia.org/wiki/File:Sword-billed_Hummingbird_(Ensifera_ensifera).jpg
![potoo Figure 6.5: Common Potoo. Image from URL: http://en.wikipedia.org/wiki/File:Nyctibius_griseus_471885191_27f931630d_o.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/potoo.jpg)
Figure 6.5: Common Potoo.
Image from URL: http://en.wikipedia.org/wiki/File:Nyctibius_griseus_471885191_27f931630d_o.jpg
Birds of Australia and Outlying Islands
![lilpenguin Figure 6.8: Little Penguin or Fairy Penguin. Image from URL: http://en.wikipedia.org/wiki/File:Eudyptula_minor_Bruny_Island.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/lilpenguin.jpg)
Figure 6.8: Little Penguin or Fairy Penguin.
Image from URL: http://en.wikipedia.org/wiki/File:Eudyptula_minor_Bruny_Island.jpg
![kingparrot Figure 6.9: Australian King Parrot. Image from URL: http://en.wikipedia.org/wiki/File:Austkingparrot.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/kingparrot.png)
Figure 6.9: Australian King Parrot.
Image from URL: http://en.wikipedia.org/wiki/File:Austkingparrot.jpg
African Birds
![ostriches Figure 6.10: Ostriches. Image from URL: http://en.wikipedia.org/wiki/File:Ostriches_cape_point_cropped.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/ostriches.jpg)
Figure 6.10: Ostriches.
Image from URL: http://en.wikipedia.org/wiki/File:Ostriches_cape_point_cropped.jpg
![hamerkop Figure 6.11: Hamerkop. Image from URL: http://en.wikipedia.org/wiki/File:Scopus_umbretta_-Serengeti,_Tanzania-8.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/hamerkop.jpg)
Figure 6.11: Hamerkop.
Image from URL: http://en.wikipedia.org/wiki/File:Scopus_umbretta_-Serengeti,_Tanzania-8.jpg
![apenguin Figure 6.13: African Penguin. Image from URL: http://en.wikipedia.org/wiki/File:508px-African.penguin.bristol.750pix_(Pingstone).jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/apenguin.jpg)
Figure 6.13: African Penguin.
Image from URL: http://en.wikipedia.org/wiki/File:508px-African.penguin.bristol.750pix_(Pingstone).jpg
![eplover Figure 6.14: Egyptian Plover. Image from URL: http://en.wikipedia.org/wiki/File:Pluvianus_aegyptius_3_Luc_Viatour.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/eplover.jpg)
Figure 6.14: Egyptian Plover.
Image from URL: http://en.wikipedia.org/wiki/File:Pluvianus_aegyptius_3_Luc_Viatour.jpg
![koribustard Figure 6.15: Kori Bustard. Image from URL: http://en.wikipedia.org/wiki/File:Ardeotis_kori_Etosha.JPG](http://www.sciencepartners.info/wp-content/uploads/2012/08/koribustard.jpg)
Figure 6.15: Kori Bustard.
Image from URL: http://en.wikipedia.org/wiki/File:Ardeotis_kori_Etosha.JPG
![yellowbilled Figure 6.16: Yellow-Billed Hornbill. Image from URL: http://en.wikipedia.org/wiki/File:Tockus_flavirostris_-Discovery_Cove_-Orlando-8.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/yellowbilled.jpg)
Figure 6.16: Yellow-Billed Hornbill.
Image from URL: http://en.wikipedia.org/wiki/File:Tockus_flavirostris_-Discovery_Cove_-Orlando-8.jpg
![trumpeter Figure 6.17: Trumpeter Hornbill. Image from URL: http://en.wikipedia.org/wiki/File:Stavenn_Ceratogymna.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/trumpeter.jpg)
Figure 6.17: Trumpeter Hornbill.
Image from URL: http://en.wikipedia.org/wiki/File:Stavenn_Ceratogymna.jpg
Birds of North America
![pygmy-owl Figure 6.22: Northern Pygmy-owl. Image from URL: http://en.wikipedia.org/wiki/File:Northern_pygmy-owl.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/pygmy-owl.jpg)
Figure 6.22: Northern Pygmy-owl.
Image from URL: http://en.wikipedia.org/wiki/File:Northern_pygmy-owl.jpg
![baldeagle Figure 6.25: American Bald Eagle. Image from URL: http://en.wikipedia.org/wiki/File:Haliaeetus_leucocephalus_-Skagit_valley-8-2c.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/baldeagle.jpg)
Figure 6.25: American Bald Eagle.
Image from URL:
http://en.wikipedia.org/wiki/File:Haliaeetus_leucocephalus_-Skagit_valley-8-2c.jpg
![amrobin Figure 6.26: American Robin. Image from URL: http://en.wikipedia.org/wiki/File:Turdus-migratorius-002.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/amrobin.jpg)
Figure 6.26: American Robin.
Image from URL: http://en.wikipedia.org/wiki/File:Turdus-migratorius-002.jpg
![amraven Figure 6.27: American Raven. Image from URL: http://en.wikipedia.org/wiki/File:Corvus_corax_(NPS).jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/amraven.jpg)
Figure 6.27: American Raven.
Image from URL: http://en.wikipedia.org/wiki/File:Corvus_corax_(NPS).jpg
![blueheron Figure 6.28: Great Blue Heron. Image from URL: http://en.wikipedia.org/wiki/File:Lightmatter_greatblueheron2.jpg](http://www.sciencepartners.info/wp-content/uploads/2012/08/blueheron.jpg)
Figure 6.28: Great Blue Heron.
Image from URL: http://en.wikipedia.org/wiki/File:Lightmatter_greatblueheron2.jpg
Check Your Thinking: How many different species of hummingbirds are found in Australia? How many are found in Africa?