CLASS AVES: BIRDS
blue jay: Cyanocitta cristata
Have you ever wanted to swim year-round without ever being cold? If you have, here’s your answer: be a duck! How, you ask? I don’t know- that’s your problem!
Ducks, along with all other birds, have two layers of feathers- contour feathers and downy feathers. Downy feathers are soft and fluffy and are used to keep a bird warm, since birds are endotherms. Contour feathers are strong and light- perfect for flight (if you were the kid who wanted to fly, these ones are more your type). But these special feathers aren’t the only thing used for flight, - figures that flying would be more complicated than year-round swimming- you also need special bones. Birds have a complex skeleton made up of almost hollow bones with braces inside. Many of the bones are also joined together. Both of these adaptations allow for a light yet strong skeleton (sorry to burst your bubble- good luck getting those!) Bird eggs are fertilized internally, then a shell forms around the developing embryo. This way, every baby bird is equipped with a protective environment and food supply from the start. These lucky animals also get a 4-chambered heart like ours. This means that no mixing of oxygenated and deoxygenated blood ever occurs. The blood flows through a system of arteries, capillaries, and veins as it is pumped throughout the bird’s body.
If you live in Eastern to Central America, you probably recognize the bird above. The blue jay, or Cyanocitta cristata, is common in forested areas, feeding on seeds, nuts, acorns, caterpillars, beetles, and grasshoppers. A blue jay is known for its “Jay! Jay!” call, but that’s not all its voice is used for. These intelligent birds can mimic a large variety of calls, including a hawk’s, which can be used to warn friends that a hawk is near or scare another species. The oldest blue jay found in the wild was 17 years of age, but most live to about 7 years.